comment?D=FDA-2019-N-1482-0001 07 16 HIA Public... · HIA, our advocacy partner the U.S. Hemp Roundtable, and many scholars and others disagree with the agency’s position. Section

www.TheHIA.org 24 W Camelback Rd. #A449

(707) 874-3648 Phoenix, AZ

85013

July 16, 2019 Submitted Electronically Via https://www.regulations.gov/comment?D=FDA-2019-N-1482-0001 Dockets Management Staff (HFA-305) Food and Drug Administration 5630 Fishers Lane, Rm. 1061 Rockville, MD 20852 Re: Docket ID FDA-2019-N-1482-0001; Scientific Data and Information About Products

Containing Cannabis or Cannabis-Derived Compounds; Request for Comments To Whom It May Concern:

The Hemp Industries Association® (“HIA”) appreciates the opportunity to provide comments to the Food and Drug Administration (“FDA”) on the Scientific Data and Information About Products Containing Cannabis or Cannabis-Derived Compounds. Founded in 1994, the Hemp Industries Association is a membership-based non-profit trade association formed to educate the public and advance the hemp economy for the benefit of our Members, the public, and the planet. With over 1,700 members representing the industry from farm to finished product, the HIA® operates to support industry initiatives and now help re-establish the crop’s status as a beneficial food, fiber and therapeutic.

I. INTRODUCTION

The HIA, aligned with the clear intent of Congress, believes expedited consideration must be taken to open safe markets for this important crop. As such, the HIA recommends the FDA permit hemp-derived products to be excluded from DSHEA, as the crop and its extracts were in commerce prior to 1994 marketed as Cannabis oils; and that the FDA specifically uses its authority to allow cannabidiol (hereinafter “CBD”) products to be manufactured and marketed as dietary supplements and food additives despite the Investigational New Drug preclusion referenced in §201(ff)(3)(B)(ii) of the Food, Drug & Cosmetic Act (hereinafter the “IND Preclusion”).1 The League of Nations (now the United Nations) reported in 1934 that Cannabis and its compounds

1 Although the FDA has taken the position that dietary supplements and food are precluded from containing CBD, the HIA, our advocacy partner the U.S. Hemp Roundtable, and many scholars and others disagree with the agency’s position. Section 201(ff)(3)(B)(ii) of the FD&CA excludes from the definition of dietary supplement “an article authorized for investigation as a new drug…for which substantial clinical investigations have been instituted and for which the existence of such investigations has been made public,” unless the article was previously marketed as a dietary supplement or as a food. However, we contend that CBD does not fall under this preclusion because the Epidiolex clinical trials on CBD were extremely limited in scope and funding, and publication of these trials has also been limited.

http://www.thehia.org/

https://www.regulations.gov/comment?D=FDA-2019-N-1482-0001

July 16, 2019 Page 2

were a “mild counter irritant “and were beneficial for “encouraging sleep and soothing restlessness.” These products were manufactured by companies like Eli Lilly since the 1860s, not to mention used for millennia, naturally evolving with mankind.

Scientific research, while not abundant due to federal regulation prohibiting open research for over fifty years, but nonetheless valuable, provides evidence that non-intoxicating cannabinoids found in Cannabis like CBD are safe. Clinical trials dating 19952 and 20113 in medically sensitive populations and healthy populations found CBD is well tolerated with side effects occurring at levels up to 1500mg per serving. In addition, a 20184 study provided more evidence that healthy volunteers tolerated CBD doses up to 1500mg per serving with mild to moderate side effects, most commonly diarrhea and headache. This serving size of 1500mg is 10 times and up to 100 times higher than traditional servings used in the supplement and nutritional space.

However, just because side effects occur at high level dosages of pure CBD does not give reason for strict regulatory control. Safety concerns exist for various supplements and foods, but these products are still sold at local grocery stores, with risks of drug-drug interactions mitigated by health care providers. For example, supplements like Saint John’s Wort, Aconite, and Kava as well as Bitter Orange and Grapefruit, can cause serious drug-drug interactions as well as side effects such as liver damage, fainting, nausea, low blood pressure and even death.

Over-the-counter products like acetaminophen cause liver failure in high levels. Ibuprofen causes gastric bleeding with over 100,000 hospitalizations and 16,500 deaths per year, and even Epsom salts cause risk of intestinal rupture. Conversely, legal but age-restricted products like alcohol and tobacco are known to cause cancer, addiction, pregnancy risk, impairment and emphysema. Even too much water can kill an individual.

The FDA should take precautionary measures as they relate to these products; however, existing precautions are appropriate to ensure safety measures are intact. In order to protect the consumer, we believe the FDA should take the following courses of action.

1. Use the FDA’s authority to exclude hemp and its derivatives from DSHEA and allow for the manufacture and marketing of CBD and cannabinoids as dietary supplements and food additive, despite the IND Preclusion.

2. Work with Congress to appropriate research funding to study drug-drug interactions of hemp (and Cannabis) derived products.

3. Take action against companies making medical claims and adulterated products. 4. Work with industry organizations like the Hemp Industries Association and U.S. Hemp

Authority™ to develop proper cannabinoid analysis methods and labeling requirements related to consumer information, warnings, restrictions and urinalysis risk.

2 Zuardi, A.W., et al. (1995) Antipsychotic effect of cannabidiol. J. Clin Psychiatry, 56 (10); 485-6. 3 Bergamaschi M.M., et al. (2011) Safety and side effects of cannabidiol, a Cannabis sativa constituent. Curr Drug

Saff. 6 (4): 237-49. 4Taylor L., et al. (2018) A Phase I, Randomized, Double-Blind, Placebo-Controlled Single Ascending Dose,

Multiple Dose and Food Effect Trial of Safety, Tolerability and Pharmacokinetics of Highly Purified Cannabidiol in Healthy Subjects. CNS Drugs, 32, (11): 1053-1067. Attached hereto as Exhibit H.


5. Disallow/prohibit the manufacture and marketing of synthetic cannabinoids for human and animal consumption and application.

II. HEALTH & SAFETY RISKS

A. RESEARCH / STUDIES ON CBD’S SAFETY PROFILE

CBD has been evaluated for safety and side effect profiles in a number of studies including meta-analysis that evaluated over 100 clinical reports at a wide range of dosage and showed minimal levels of adverse side effects and no significant toxicity.

For example, please see Exhibit A attached hereto, “An Update on Safety and Side Effects of Cannabidiol: A Review of Clinical Data and Relevant Animal Studies”5 The results of this study show that, in general, the favorable safety profile of CBD in humans was confirmed and extended by the reviewed research. The majority of studies were performed for treatment of epilepsy and psychotic disorders. Here, the most commonly reported side effects were tiredness, diarrhea, and changes of appetite/weight. In comparison with other drugs, used for the treatment of these medical conditions, CBD has a better side effect profile.

Another example can be found at Exhibit B attached hereto, “Safety and Side Effects of Cannabidiol, a Cannabis sativa Constituent.”6 Several studies reviewed within this research suggest that CBD is non-toxic in non-transformed cells and does not induce changes on food intake, does not induce catalepsy, does not affect physiological parameters (heart rate, blood pressure and body temperature), does not affect gastrointestinal transit and does not alter psychomotor or psychological functions. It also demonstrates that chronic use and high doses up to 1,500 mg/day of CBD are reportedly well tolerated in humans.

Exhibit C attached hereto, “A Phase I, Randomized, Double-Blind, Placebo-Controlled, Single Ascending Dose, Multiple Dose, and Food Effect Trial of the Safety, Tolerability and Pharmacokinetics of Highly Purified Cannabidiol in Healthy Subjects,”7 involves 24 subjects tested with multiple doses of CBD ranging from 750 to 6000mg. Results show that CBD was generally well-tolerated and all adverse events were of mild or moderate severity; none were severe or serious. Diarrhea, nausea, headache, and somnolence were the most common adverse events across all trial arms, with an increased incidence of some gastrointestinal and nervous system disorder adverse events (most notably diarrhea and headache) apparent in subjects taking CBD compared with placebo. There were no clinically significant findings for laboratory parameters, physical examination, vital signs, ECG or body weight in any arm of the trial.

Additionally, Exhibit D attached hereto, “Prolonged Cannabidiol Treatment Lacks on Detrimental Effects on Memory, Motor Performance and Anxiety in C57BL/6J Mice,”8 shows prolonged cannabidiol treatment has no detrimental effects on memory, motor performance and anxiety in mice. Mice were daily injected with 20 mg/kg CBD for six weeks, and the results demonstrated

5 By Kerstin Iffland and Franjo Grotenhermen (2017). 6 Mateus Machado Bergamaschi, et al. (2011). 7 Taylor, et al. (2018). 8 Schleicher, et al. (2019).


CBD treatment does not influence motor performance, spatial learning and long-term memory, anxiety under stress, or hippocampal neuron number. Our results demonstrate that prolonged CBD treatment has no negative effect on the behavior of adult mice.

Exhibit E attached hereto, “Abuse Potential Assessment of Cannabidiol (CBD) in Recreational Polydrug Users: A Randomized, Double-Blind, Controlled Trial,”9 shows administration of a therapeutic dose of CBD (750 mg) showed significantly low abuse potential in a highly sensitive population of polydrug users; and that although high and supratherapeutic doses of CBD (1500 mg and 4500 mg, respectively) had detectable subjective effects compared with placebo, the effects were significantly lower than those observed with alprazolam and dronabinol.

B. JUNE 2018 WHO ECDD CRITICAL REVIEW REPORT ON CANNABIDIOL

The World Health Organization’s Expert Committee on Drug Dependence performed a Critical Review of CBD in June of 2018. According to that Report, attached here as Exhibit F:

• CBD is generally well tolerated with a good safety profile; • In humans, CBD exhibits no effects indicative of any abuse or dependency potential; and • To date there is no evidence of recreational use of CBD or any public health-related.

problems associated with the use of pure CBD.

C. LIVER TOXICITY

CBD has been shown to adversely affect liver function at high doses in subjects using other medications or those with moderate to severe hepatic impairment. The research also shows a contrast between the performance and side effects for purified CBD versus CBD-rich hemp extract.

Exhibit G attached hereto, “Key Pharmacological Differences Between Side Effects of Refined, Pharmaceutical CBD Formulations and Whole Plant Extracts,”10 involved an open-label trial of pure CBD with Lennox-Gastaut and Dravet patients wherein 79% of all patients reported side effects. Serious side effects in 30% of patients included status epilepticus in 6%, severe hepatotoxicity in one (1) patient, and hyperammonemia in another. This same research also shows that an Israeli study of Cannabis versus epilepsy, however, used natural extracts (as opposed to pure CBD) with a ratio of 20:1 CBD:THC and no hepatic side effects were noted. The CBD-rich extract group had a lower effective dose on average, 6.1 mg/kg while purified CBD required 27.1 mg/kg. Purified CBD also tripled the rate of both mild side effects such as appetite alteration, sleepiness, gastrointestinal disturbances/diarrhea, weight changes, fatigue, nausea, and severe side effects such as thrombocytopenia, respiratory infections, and alteration of liver enzymes.11 Exhibit H attached hereto, “A Phase 1, Open-Label, Parallel-Group, Single-Dose Trial of the Pharmacokinetics and Safety of Cannabidiol (CBD) in Subjects with Mild to Severe Hepatic 9 Schoedel, et al. (2018). 10 Holley, et al. (2018). 11 Fabricio A. Pamplona, Lorenzo Rolim da Silva, and Ana Carolina Coan; Potential Clinical Benefits of CBD-Rich

Cannabis Extracts Over Purified CBD in Treatment-Resistant Epilepsy: Observational Data Meta-analysis. Neurol. 9:759 (2018).


Impairment,”12 involved 22 subjects with hepatic impairment. There were clinically relevant increases [of liver dysfunction measurements] in subjects with moderate and severe hepatic impairment, relative to subjects with normal hepatic function. These findings indicate that dose modification is necessary in patients with moderate and severe hepatic impairment, and a lower starting dose and slower titration are necessary based on benefit-risk. It also shows that CBD was well tolerated, and there were no serious adverse events reported during the trial.

The differences between the high doses of CBD referenced in Exhibits G and H directly above and the average serving size of an oral dietary supplement product generally available in the open market must be recognized. For example, a general serving size is one (1) capsule at 15 mg of CBD each or a dropper of tincture containing 15 mg of CBD, which is one-thirteenth the size of a dose provided in the Exhibit H subjects with hepatic impairment.

The National Institute of Health’s Drug Record Report on acetaminophen indicates that chronic therapy with acetaminophen in doses of four (4) grams daily has been found to lead to transient elevations in serum aminotransferase levels in a proportion of subjects, generally starting after three (3) to seven (7) days, and with peak values rising above three-fold elevated in 39% of persons.13

In comparison, acetaminophen induces elevated liver enzymes at less than twice the maximum dose whereas CBD has been shown to increase liver enzymes in patients with an impaired liver at doses greater than thirteen times the standard serving size.

D. SYNTHETIC CANNABINOIDS

The public health dangers associated with synthetic cannabinoids, which include death, have been widely publicized14,15 and cannabimimetic agents are controlled substances for legitimate reasons. The HIA strongly believes that synthetic cannabinoids have no place in the human or animal health, food, or cosmetic systems. The FDA should prohibit the manufacture and marketing of synthetic cannabinoids for human and animal consumption and application.

III. MANUFACTURING AND PRODUCT QUALITY

In addition to requesting that the FDA use its authority to allow for the manufacture of CBD as a dietary supplement and food additive despite the IND Preclusion, the HIA believes that the Codes of Federal Regulation relevant to the manufacturing and product quality of dietary supplements, food/food additives, and cosmetics need only be augmented to accommodate hemp extract, hemp-derived CBD and other cannabinoids by addressing cannabinoid strength and purity. The FDA should work with industry organizations like the Hemp Industries Association and U.S. Hemp Authority to develop proper cannabinoid analysis methods.

12 Taylor, et al. (2019). 13 https://livertox.nih.gov/Acetaminophen.htm. 14 https://www.cdc.gov/mmwr/volumes/67/wr/mm6720a5.htm?s_cid=mm6720a5_w#T1_down;

https://www.cdc.gov/nceh/hsb/chemicals/sc/default.html; https://www.cdc.gov/mmwr/volumes/67/wr/mm6721a4.htm.

15 https://www.fda.gov/news-events/press-announcements/statement-fda-warning-about-significant-health-risks-contaminated-illegal-synthetic-cannabinoid

https://livertox.nih.gov/Acetaminophen.htm

https://www.cdc.gov/mmwr/volumes/67/wr/mm6720a5.htm?s_cid=mm6720a5_w#T1_down

https://www.cdc.gov/nceh/hsb/chemicals/sc/default.html

https://www.cdc.gov/mmwr/volumes/67/wr/mm6721a4.htm

https://www.fda.gov/news-events/press-announcements/statement-fda-warning-about-significant-health-risks-contaminated-illegal-synthetic-cannabinoid

https://www.fda.gov/news-events/press-announcements/statement-fda-warning-about-significant-health-risks-contaminated-illegal-synthetic-cannabinoid


IV. MARKETING/LABELING/SALES

In addition to requesting that the FDA use its authority to exclude hemp and its derivatives from DSHEA and allow for the marketing of CBD as a dietary supplement and food additive despite the IND Preclusion, the HIA believes that the Codes of Federal Regulation relevant to the marketing and labeling of dietary supplements, food/food additives, and cosmetics need only be augmented to accommodate hemp extract, hemp-derived CBD and other cannabinoids by regulating strength and purity, as well as requiring the labeling of (1) milligrams of CBD and primary cannabinoids per serving, (2) milligrams of CBD and primary cannabinoids per package, and (3) appropriate warnings, including urinalysis risk. The FDA should work with industry organizations like the Hemp Industries Association and U.S. Hemp Authority to develop proper labeling requirements related to this important consumer information.

* * * Thank you for the opportunity to comment on this matter, and we would be happy to answer any questions or discuss our comments with the agency in more detail.

Respectfully Submitted,

Sent Without Signatures to Avoid Delay THE BOARD OF DIRECTORS EXECUTIVE DIRECTOR

Joy Beckerman, President Colleen Keahey Lanier Rick Trojan, Vice President Tyler Frank, Secretary David Bush, Esq., Treasurer Anndrea Hermann M.Sc, B.Gs, P.Ag Courtney N. Moran Annie Rouse Dan Herer Brandon Beatty

Enclosures: ● Exhibit A: An Update on Safety and Side Effects of Cannabidiol: A Review of Clinical

Data and Relevant Animal Studies (2017) ● Exhibit B: Safety and Side Effects of Cannabidiol, a Cannabis sativa Constituent (2011) ● Exhibit C: A Phase I, Randomized, Double-Blind, Placebo-Controlled, Single Ascending

Dose, Multiple Dose, and Food Effect Trial of the Safety, Tolerability and Pharmacokinetics of Highly Purified Cannabidiol in Healthy Subjects (2018)

● Exhibit D: Prolonged Cannabidiol Treatment Lacks on Detrimental Effects on Memory, Motor Performance and Anxiety in C57BL/6J Mice (2019)

● Exhibit E: Abuse Potential Assessment of Cannabidiol (CBD) in Recreational Polydrug Users: A Randomized, Double-Blind, Controlled Trial (2018)


● Exhibit F: June 2018 World Health Organization ECDD Critical Review Report on Cannabidiol (CBD) (2018)

● Exhibit G: Key Pharmacological Differences Between Side Effects of Refined, Pharmaceutical CBD Formulations and Whole Plant Extracts (2018)

● Exhibit H: A Phase 1, Open-Label, Parallel-Group, Single-Dose Trial of the Pharmacokinetics and Safety of Cannabidiol (CBD) in Subjects with Mild to Severe Hepatic Impairment (2019)

Exhibit A

REVIEW Open Access

An Update on Safety and Side Effects of Cannabidiol:A Review of Clinical Data and Relevant Animal StudiesKerstin Iffland and Franjo Grotenhermen

AbstractIntroduction: This literature survey aims to extend the comprehensive survey performed by Bergamaschi et al. in2011 on cannabidiol (CBD) safety and side effects. Apart from updating the literature, this article focuses on clin-ical studies and CBD potential interactions with other drugs.Results: In general, the often described favorable safety profile of CBD in humans was confirmed and extendedby the reviewed research. The majority of studies were performed for treatment of epilepsy and psychotic dis-orders. Here, the most commonly reported side effects were tiredness, diarrhea, and changes of appetite/weight.In comparison with other drugs, used for the treatment of these medical conditions, CBD has a better side effectprofile. This could improve patients’ compliance and adherence to treatment. CBD is often used as adjunct ther-apy. Therefore, more clinical research is warranted on CBD action on hepatic enzymes, drug transporters, andinteractions with other drugs and to see if this mainly leads to positive or negative effects, for example, reducingthe needed clobazam doses in epilepsy and therefore clobazam’s side effects.Conclusion: This review also illustrates that some important toxicological parameters are yet to be studied, forexample, if CBD has an effect on hormones. Additionally, more clinical trials with a greater number of participantsand longer chronic CBD administration are still lacking.

Keywords: cannabidiol; cannabinoids; medical uses; safety; side effects; toxicity

IntroductionSince several years, other pharmacologically relevantconstituents of the Cannabis plant, apart from D9-THC, have come into the focus of research and legisla-tion. The most prominent of those is cannabidiol(CBD). In contrast to D9-THC, it is nonintoxicating,but exerts a number of beneficial pharmacologicaleffects. For instance, it is anxiolytic, anti-inflammatory,antiemetic, and antipsychotic. Moreover, neuropro-tective properties have been shown.1,2 Consequently,it could be used at high doses for the treatment of avariety of conditions ranging in psychiatric disorderssuch as schizophrenia and dementia, as well as diabe-tes and nausea.1,2

At lower doses, it has physiological effects that pro-mote and maintain health, including antioxidative,anti-inflammatory, and neuroprotection effects. For in-stance, CBD is more effective than vitamin C and E as aneuroprotective antioxidant and can ameliorate skinconditions such as acne.3,4

The comprehensive review of 132 original studies byBergamaschi et al. describes the safety profile of CBD,mentioning several properties: catalepsy is not inducedand physiological parameters are not altered (heartrate, blood pressure, and body temperature). Moreover,psychological and psychomotor functions are not ad-versely affected. The same holds true for gastrointesti-nal transit, food intake, and absence of toxicity for

nova-Institut, Hurth, Germany.

*Address correspondence to: Kerstin Iffland, nova-Institut, Industriestraße 300, Hurth 50354, Germany, E-mail: [email protected]

ª Kerstin Iffland and Franjo Grotenhermen 2017; Published by Mary Ann Liebert, Inc. This is an Open Access article distributed under the terms ofthe Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original workis properly cited.

Cannabis and Cannabinoid ResearchVolume 2.1, 2017DOI: 10.1089/can.2016.0034

Cannabis and

Cannabinoid Research

139

nontransformed cells. Chronic use and high doses ofup to 1500 mg per day have been repeatedly shownto be well tolerated by humans.1

Nonetheless, some side effects have been reportedfor CBD, but mainly in vitro or in animal studies.They include alterations of cell viability, reduced fertil-ization capacity, and inhibition of hepatic drug metab-olism and drug transporters (e.g., p-glycoprotein).1

Consequently, more human studies have to be con-ducted to see if these effects also occur in humans. Inthese studies, a large enough number of subjects haveto be enrolled to analyze long-term safety aspects andCBD possible interactions with other substances.

This review will build on the clinical studies men-tioned by Bergamaschi et al. and will update their sur-vey with new studies published until September 2016.

Relevant Preclinical StudiesBefore we discuss relevant animal research on CBDpossible effects on various parameters, several impor-tant differences between route of administration andpharmacokinetics between human and animal studieshave to be mentioned. First, CBD has been studied inhumans using oral administration or inhalation.Administration in rodents often occures either via in-traperitoneal injection or via the oral route. Second,the plasma levels reached via oral administration inrodents and humans can differ. Both these observa-tions can lead to differing active blood concentrationsof CBD.1,5,6

In addition, it is possible that CBD targets differ be-tween humans and animals. Therefore, the same bloodconcentration might still lead to different effects. Evenif the targets, to which CBD binds, are the same in bothstudied animals and humans, for example, the affinityor duration of CBD binding to its targets might differand consequently alter its effects.

The following study, which showed a positive effectof CBD on obsessive compulsive behavior in miceand reported no side effects, exemplifies the existingpharmacokinetic differences.5 When mice and hu-mans are given the same CBD dose, more of the com-pound becomes available in the mouse organism. Thishigher bioavailability, in turn, can cause larger CBDeffects.

Deiana et al. administered 120 mg/kg CBD eitherorally or intraperitoneally and measured peak plasmalevels.5 The group of mice, which received oral CBD,had plasma levels of 2.2 lg/ml CBD. In contrast, i.p. in-jections resulted in peak plasma levels of 14.3 lg/ml.

Administering 10 mg/kg oral CBD to humans leadsto blood levels of 0.01 lg/ml.6 This corresponds tohuman blood levels of 0.12 lg/ml, when 120 mg/kgCBD was given to humans. This calculation was per-formed assuming the pharmacokinetics of a hydro-philic compound, for simplicity’s sake. We are awarethat the actual levels of the lipophilic CBD will vary.

A second caveat of preclinical studies is that supra-physiological concentrations of compounds are oftenused. This means that the observed effects, for instance,are not caused by a specific binding of CBD to one of itsreceptors but are due to unspecific binding followingthe high compound concentration, which can inacti-vate the receptor or transporter.

The following example and calculations will dem-onstrate this. In vitro studies have shown that CBD in-hibits the ABC transporters P-gp (P glycoproteinalso referred to as ATP-binding cassette subfamily Bmember 1 = ABCB1; 3–100 lM CBD) and Bcrp(Breast Cancer Resistance Protein; also referred to asABCG2 = ATP-binding cassette subfamily G mem-ber 2).7 After 3 days, the P-gp protein expressionwas altered in leukemia cells. This can have severalimplications because various anticancer drugs alsobind to these membrane-bound, energy-dependent ef-flux transporters.1 The used CBD concentrations aresupraphysiological, however, 3 lM CBD approximatelycorresponds to plasma concentrations of 1 lg/ml. Onthe contrary, a 700 mg CBD oral dose reached a plasmalevel of 10 ng/ml.6 This means that to reach a 1 lg/mlplasma concentration, one would need to administerconsiderably higher doses of oral CBD. The highestever applied CBD dose was 1500 mg.1 Consequently,more research is warranted, where the CBD effect onABC transporters is analyzed using CBD concentra-tions of, for example, 0.03–0.06 lM. The rationale be-hind suggesting these concentrations is that studiessummarized by Bih et al. on CBD effect on ABCC1and ABCG2 in SF9 human cells showed that a CBDconcentration of 0.08 lM elicited the first effect.7

Using the pharmacokinetic relationships mentionedabove, one would need to administer an oral CBD doseof 2100 mg CBD to affect ABCC1 and ABCG2. Weused 10 ng/ml for these calculations and the ones inTable 1,6,8 based on a 6-week trial using a daily oral ad-ministration of 700 mg CBD, leading to mean plasmalevels of 6–11 ng/ml, which reflects the most realisticscenario of CBD administration in patients.6 Thatthese levels seem to be reproducible, and that chronicCBD administration does not lead to elevated mean

Iffland and Grotenhermen; Cannabis and Cannabinoid Research 2017, 2.1http://online.liebertpub.com/doi/10.1089/can.2016.0034

140

blood concentrations, was shown by another study. Asingle dose of 600 mg led to reduced anxiety andmean CBD blood concentrations of 4.7–17 ng/ml.9

It also seems warranted to assume that the meanplasma concentration exerts the total of observed CBDeffects, compared to using peak plasma levels, whichonly prevail for a short amount of time. This is notwithstanding, that a recent study measured Cmaxvalues for CBD of 221 ng/ml, 3 h after administrationof 1 mg/kg fentanyl concomitantly with a single oraldose of 800 mg CBD.10

CBD-drug interactionsCytochrome P450-complex enzymes. This paragraphdescribes CBD interaction with general (drug)-metabolizing enzymes, such as those belonging tothe cytochrome P450 family. This might have an effectfor coadministration of CBD with other drugs.7 Forinstance, CBD is metabolized, among others, via theCYP3A4 enzyme. Various drugs such as ketoconazol,itraconazol, ritonavir, and clarithromycin inhibit thisenzyme.11 This leads to slower CBD degradation andcan consequently lead to higher CBD doses that arelonger pharmaceutically active. In contrast, pheno-barbital, rifampicin, carbamazepine, and phenytoininduce CYP3A4, causing reduced CBD bioavailabili-ty.11 Approximately 60% of clinically prescribeddrugs are metabolized via CYP3A4.1 Table 1 showsan overview of the cytochrome inhibiting potentialof CBD. It has to be pointed out though, that thein vitro studies used supraphysiological CBD concen-trations.

Studies in mice have shown that CBD inactivatescytochrome P450 isozymes in the short term, butcan induce them after repeated administration. Thisis similar to their induction by phenobarbital, therebyimplying the 2b subfamily of isozymes.1 Anotherstudy showed this effect to be mediated by upregula-

tion of mRNA for CYP3A, 2C, and 2B10, after re-peated CBD administration.1

Hexobarbital is a CYP2C19 substrate, which is anenzyme that can be inhibited by CBD and can conse-quently increase hexobarbital availability in the organ-ism.12,13 Studies also propose that this effect might becaused in vivo by one of CBD metabolites.14,15 Gener-ally, the metabolite 6a-OH-CBD was already demon-strated to be an inducer of CYP2B10. Recorcinol wasalso found to be involved in CYP450 induction. Theenzymes CYP3A and CYP2B10 were induced after pro-longed CBD administration in mice livers, as well as forhuman CYP1A1 in vitro.14,15 On the contrary, CBDinduces CYP1A1, which is responsible for degradationof cancerogenic substances such as benzopyrene.CYP1A1 can be found in the intestine and CBD-induced higher activity could therefore prevent absorp-tion of cancerogenic substances into the bloodstreamand thereby help to protect DNA.2

Effects on P-glycoprotein activity and other drugtransporters. A recent study with P-gp, Bcrp, andP-gp/Bcrp knockout mice, where 10 mg/kg was injectedsubcutaneously, showed that CBD is not a substrate ofthese transporters itself. This means that they do notreduce CBD transport to the brain.16 This phenome-non also occurs with paracetamol and haloperidol,which both inhibit P-gp, but are not actively trans-ported substrates. The same goes for gefitinib inhibi-tion of Bcrp.

These proteins are also expressed at the blood–brainbarrier, where they can pump out drugs such as risper-idone. This is hypothesized to be a cause of treatment re-sistance.16 In addition, polymorphisms in these genes,making transport more efficient, have been implied ininterindividual differences in pharmacoresistance.10

Moreover, the CBD metabolite 7-COOH CBD mightbe a potent anticonvulsant itself.14 It will be interesting

Table 1. Inhibition of Human Metabolic Enzymes by Exogenous Cannabinoids In Vitro and the Extrapolated Levelsof Oral Daily CBD Administration in Humans Needed to Reach These In Vitro Concentrations (Adapted)6,8

CYP-450 isoform 1A1 1A2 1B1 2A6 2B6 2C9 2D6 3A4 3A5 3A7

CBD (in lM) 0.2 2.7 3.6 55.0 0.7 0.9–9.9 1.2–2.7 1.0 0.2 12.3aExtrapolated oral daily CBD doses

to reach the levels above (in mg)4900 63,000 84,000 1.28 Mio. Ca. 16,000 21,000–231,000 28,000–63,000 Ca. 23,000 4900 0.29 Mio.

aThe calculations made here are based on the assumption that the CBD distribution in the blood follows the pharmacokinetics of a hydrophilicsubstance such as alcohol. The reality is more complex, because CBD is lipophilic and, for example, will consequently accumulate in fat tissue.These calculations were made with the intention to give the reader an impression and an approximation of the supraphysiological levels used inin vitro studies.


141

to see whether it is a P-gp substrate and alters pharma-cokinetics of coadministered P-gp-substrate drugs.

An in vitro study using three types of trophoblast celllines and ex vivo placenta, perfused with 15 lM CBD,found BCRP inhibition leading to accumulation of xe-nobiotics in the fetal compartment.17 BCRP is expressedat the apical side of the syncytiotrophoblast and removesa wide variety of compounds forming a part of the pla-cental barrier. Seventy-two hours of chronic incubationwith 25 lM CBD also led to morphological changes inthe cell lines, but not to a direct cytotoxic effect. Incontrast, 1 lM CBD did not affect cell and placenta vi-ability.17 The authors consider this effect cytostatic.Nicardipine was used as the BCRP substrate in thein vitro studies, where the Jar cell line showed the larg-est increase in BCRP expression correlating with thehighest level of transport.17,and references therein

The ex vivo study used the antidiabetic drug andBCRP substrate glyburide.17 After 2 h of CBD perfu-sion, the largest difference between the CBD and theplacebo placentas (n = 8 each) was observed. CBD inhi-bition of the BCRP efflux function in the placental cot-yledon warrants further research of coadministrationof CBD with known BCRP substrates such as nitrofur-antoin, cimetidine, and sulfasalazine. In this study, adose–response curve should be established in maleand female subjects (CBD absorption was shown tobe higher in women) because the concentrations usedhere are usually not reached by oral or inhaled CBD ad-ministration. Nonetheless, CBD could accumulate inorgans physiologically restricted via a blood barrier.17

Physiological effectsCBD treatment of up to 14 days (3–30 mg/kg b.w. i.p.)did not affect blood pressure, heart rate, body temper-ature, glucose levels, pH, pCO2, pO2, hematocrit, K+ orNa+ levels, gastrointestinal transit, emesis, or rectaltemperature in a study with rodents.1

Mice treated with 60 mg/kg b.w. CBD i.p. for 12weeks (three times per week) did not show ataxia, ky-phosis, generalized tremor, swaying gait, tail stiffness,changes in vocalization behavior or open-field physio-logical activity (urination, defecation).1

Neurological and neurospychiatric effectsAnxiety and depression. Some studies indicate thatunder certain circumstances, CBD acute anxiolytic ef-fects in rats were reversed after repeated 14-day admin-istration of CBD.2 However, this finding might dependon the used animal model of anxiety or depression.

This is supported by a study, where CBD was admin-istered in an acute and ‘‘chronic’’ (2 weeks) regi-men, which measured anxiolytic/antidepressant effects,using behavioral and operative models (OBX = olfactorybulbectomy as model for depression).18 The only ob-served side effects were reduced sucrose preference,reduced food consumption and body weight in thenonoperated animals treated with CBD (50 mg/kg).Nonetheless, the behavioral tests (for OBX-induced hy-peractivity and anhedonia related to depression andopen field test for anxiety) in the CBD-treated OBX an-imals showed an improved emotional response. Usingmicrodialysis, the researchers could also show elevated5-HT and glutamate levels in the prefrontal cortex ofOBX animals only. This area was previously describedto be involved in maladaptive behavioral regulation indepressed patients and is a feature of the OBX animalmodel of depression. The fact that serotonin levels wereonly elevated in the OBX mice is similar to CBD differ-ential action under physiological and pathological con-ditions.

A similar effect was previously described in anxietyexperiments, where CBD proved to be only anxiolyticin subjects where stress had been induced before CBDadministration. Elevated glutamate levels have beenproposed to be responsible for ketamine’s fast antide-pressant function and its dysregulation has been de-scribed in OBX mice and depressed patients. ChronicCBD treatment did not elicit behavioral changes inthe nonoperated mice. In contrast, CBD was able to al-leviate the affected functionality of 5HT1A receptorsin limbic brain areas of OBX mice.18 and references therein

Schiavon et al. cite three studies that used chronicCBD administration to demonstrate its anxiolytic effectsin chronically stressed rats, which were mostly mediatedvia hippocampal neurogenesis.19 and references therein

For instance, animals received daily i.p. injections of5 mg/kg CBD. Applying a 5HT1A receptor antagonistin the DPAG (dorsal periaqueductal gray area), it wasimplied that CBD exerts its antipanic effects via theseserotonin receptors. No adverse effects were reportedin this study.

Psychosis and bipolar disorder. Various studies onCBD and psychosis have been conducted.20 For in-stance, an animal model of psychosis can be createdin mice by using the NMDAR antagonist MK-801.The behavioral changes (tested with the prepulse inhi-bition [PPI] test) were concomitant with decreasedmRNA expression of the NMDAR GluN1 subunit


142

gene (GRN1) in the hippocampus, decreased parvalbu-min expression (=a calcium-binding protein expressedin a subclass of GABAergic interneurons), and higherFosB/DFosB expression (=markers for neuronal activi-ty). After 6 days of MK-801 treatment, various CBDdoses were injected intraperitoneally (15, 30, 60 mg/kg)for 22 days. The two higher CBD doses had beneficial ef-fects comparable to the atypical antipsychotic drug clo-zapine and also attenuated the MK-801 effects on thethree markers mentioned above. The publication didnot record any side effects.21

One of the theories trying to explain the etiology ofbipolar disorder (BD) is that oxidative stress is crucialin its development. Valvassori et al. therefore used ananimal model of amphetamine-induced hyperactivityto model one of the symptoms of mania. Rats weretreated for 14 days with various CBD concentrations(15, 30, 60 mg/kg daily i.p.). Whereas CBD did nothave an effect on locomotion, it did increase brain-derived neurotrophic factor (BDNF) levels and couldprotect against amphetamine-induced oxidative damagein proteins of the hippocampus and striatum. No ad-verse effects were recorded in this study.22

Another model for BD and schizophrenia is PPI ofthe startle reflex both in humans and animals, whichis disrupted in these diseases. Peres et al., list five ani-mal studies, where mostly 30 mg/kg CBD was adminis-tered and had a positive effect on PPI.20 Nonetheless,some inconsistencies in explaining CBD effects onPPI as model for BD exist. For example, CBD some-times did not alter MK-801-induced PPI disruption,but disrupted PPI on its own.20 If this effect can be ob-served in future experiments, it could be considered tobe a possible side effect.

Addiction. CBD, which is nonhedonic, can reduceheroin-seeking behavior after, for example, cue-induced reinstatement. This was shown in an animalheroin self-administration study, where mice received5 mg/kg CBD i.p. injections. The observed effect lastedfor 2 weeks after CBD administration and could nor-malize the changes seen after stimulus cue-inducedheroin seeking (expression of AMPA, GluR1, andCB1R). In addition, the described study was able toreplicate previous findings showing no CBD side effectson locomotor behavior.23

Neuroprotection and neurogenesis. There are vari-ous mechanisms underlying neuroprotection, for ex-ample, energy metabolism (whose alteration has been

implied in several psychiatric disorders) and propermitochondrial functioning.24 An early study from1976 found no side effects and no effect of 0.3–300 lg/mg protein CBD after 1 h of incubation on mi-tochondrial monoamine oxidase activity in porcinebrains.25 In hypoischemic newborn pigs, CBD eliciteda neuroprotective effect, caused no side effects, andeven led to beneficial effects on ventilatory, cardiac,and hemodynamic functions.26

A study comparing acute and chronic CBD admin-istration in rats suggests an additional mechanism ofCBD neuroprotection: Animals received i.p. CBD (15,30, 60 mg/kg b.w.) or vehicle daily, for 14 days. Mito-chondrial activity was measured in the striatum, hippo-campus, and the prefrontal cortex.27 Acute and chronicCBD injections led to increased mitochondrial activity(complexes I-V) and creatine kinase, whereas no sideeffects were documented. Chronic CBD treatmentand the higher CBD doses tended to affect morebrain regions. The authors hypothesized that CBDchanged the intracellular Ca2 + flux to cause these ef-fects. Since the mitochondrial complexes I and IIhave been implied in various neurodegenerative dis-eases and also altered ROS (reactive oxygen species)levels, which have also been shown to be altered byCBD, this might be an additional mechanism ofCBD-mediated neuroprotection.1,27

Interestingly, it has recently been shown that thehigher ROS levels observed after CBD treatment wereconcomitant with higher mRNA and protein levelsof heat shock proteins (HSPs). In healthy cells, thiscan be interpreted as a way to protect against thehigher ROS levels resulting from more mitochondrialactivity. In addition, it was shown that HSP inhibitorsincrease the CBD anticancer effect in vitro.28 This is inline with the studies described by Bergamaschi et al.,which also imply ROS in CBD effect on (cancer) cellviability in addition to, for example, proapoptoticpathways such as via caspase-8/9 and inhibition ofthe procarcinogenic lipoxygenase pathway.1

Another publication studied the difference of acuteand chronic administration of two doses of CBD in non-stressed mice on anxiety. Already an acute i.p. adminis-tration of 3 mg/kg was anxiolytic to a degree comparableto 20 mg/kg imipramine (an selective serotonin reuptakeinhibitor [SSRI] commonly prescribed for anxiety anddepression). Fifteen days of repeated i.p. administrationof 3 mg/kg CBD also increased cell proliferation andneurogenesis (using three different markers) in the sub-ventricular zone and the hippocampal dentate gyrus.


143

Interestingly, the repeated administration of 30 mg/kgalso led to anxiolytic effects. However, the higherdose caused a decrease in neurogenesis and cell prolif-eration, indicating dissociation of behavioral and pro-liferative effects of chronic CBD treatment. The studydoes not mention adverse effects.19

Immune systemNumerous studies show the CBD immunomodulatoryrole in various diseases such as multiple sclerosis, ar-thritis, and diabetes. These animal and human ex vivostudies have been reviewed extensively elsewhere, butstudies with pure CBD are still lacking. Often combi-nations of THC and CBD were used. It would beespecially interesting to study when CBD is proin-flammatory and under which circumstances it isanti-inflammatory and whether this leads to side ef-fects (Burstein, 2015: Table 1 shows a summary ofits anti-inflammatory actions; McAllister et al. givean extensive overview in Table 1 of the interplay be-tween CBD anticancer effects and inflammationsignaling).29,30

In case of Alzheimer’s disease (AD), studies in miceand rats showed reduced amyloid beta neuroinflamma-tion (linked to reduced interleukin [IL]-6 and micro-glial activation) after CBD treatment. This led toamelioration of learning effects in a pharmacologicalmodel of AD. The chronic study we want to describein more detail here used a transgenic mouse model ofAD, where 2.5-month-old mice were treated with ei-ther placebo or daily oral CBD doses of 20 mg/kg for8 months (mice are relatively old at this point). CBDwas able to prevent the development of a social recog-nition deficit in the AD transgenic mice.

Moreover, the elevated IL-1 beta and TNF alpha levelsobserved in the transgenic mice could be reduced to WT(wild-type) levels with CBD treatment. Using statisticalanalysis by analysis of variance, this was shown to beonly a trend. This might have been caused by the highvariation in the transgenic mouse group, though. Also,CBD increased cholesterol levels in WT mice but not inCBD-treated transgenic mice. This was probably due toalready elevated cholesterol in the transgenic mice. Thestudy observed no side effects.31 and references within

In nonobese diabetes-prone female mice (NOD),CBD was administered i.p. for 4 weeks (5 days aweek) at a dose of 5 mg/kg per day. After CBD treat-ment was stopped, observation continued until themice were 24 weeks old. CBD treatment lead to consid-erable reduction of diabetes development (32% devel-

oped glucosuria in the CBD group compared to 100%in untreated controls) and to more intact islet of Lang-erhans cells. CBD increased IL-10 levels, which isthought to act as an anti-inflammatory cytokine inthis context. The IL-12 production of splenocytes wasreduced in the CBD group and no side effects wererecorded.32

After inducing arthritis in rats using Freund’s adju-vant, various CBD doses (0.6, 3.1, 6.2, or 62.3 mg/day) were applied daily in a gel for transdermal admin-istration for 4 days. CBD reduced joint swelling,immune cell infiltration. thickening of the synovialmembrane, and nociceptive sensitization/spontaneouspain in a dose-dependent manner, after four consecu-tive days of CBD treatment. Proinflammatory bio-markers were also reduced in a dose-dependentmanner in the dorsal root ganglia (TNF alpha) and spi-nal cord (CGRP, OX42). No side effects were evidentand exploratory behavior was not altered (in contrastto D9-THC, which caused hypolocomotion).33

Cell migrationEmbryogenesis. CBD was shown to be able to influ-ence migratory behavior in cancer, which is also an im-portant aspect of embryogenesis.1 For instance, it wasrecently shown that CBD inhibits Id-1. Helix-loop-helix Id proteins play a role in embryogenesis and nor-mal development via regulation of cell differentiation.High Id1-levels were also found in breast, prostate,brain, and head and neck tumor cells, which werehighly aggressive. In contrast, Id1 expression was lowin noninvasive tumor cells. Id1 seems to influence thetumor cell phenotype by regulation of invasion, epithe-lial to mesenchymal transition, angiogenesis, and cellproliferation.34

There only seems to exist one study that could notshow an adverse CBD effect on embryogenesis. Anin vitro study could show that the development oftwo-cell embryos was not arrested at CBD concentra-tions of 6.4, 32, and 160 nM.35

Cancer. Various studies have been performed tostudy CBD anticancer effects. CBD anti-invasive ac-tions seem to be mediated by its TRPV1 stimulationand its action on the CB receptors. Intraperitoneal ap-plication of 5 mg/kg b.w. CBD every 3 days for a total of28 weeks, almost completely reduced the developmentof metastatic nodules caused by injection of humanlung carcinoma cells (A549) in nude mice.36 This effectwas mediated by upregulation of ICAM1 and TIMP1.


144

This, in turn, was caused by upstream regulation of p38and p42/44 MAPK pathways. The typical side effects oftraditional anticancer medication, emesis, and collat-eral toxicity were not described in these studies. Conse-quently, CBD could be an alternative to other MMP1inhibitors such as marimastat and prinomastat, whichhave shown disappointing clinical results due to thesedrugs’ adverse muscoskeletal effects.37,38

Two studies showed in various cell lines and intumor-bearing mice that CBD was able to reducetumor metastasis.34,39 Unfortunately, the in vivo studywas only described in a conference abstract and noroute of administration or CBD doses were men-tioned.36 However, an earlier study used 0.1, 1.0, or1.5 lmol/L CBD for 3 days in the aggressive breast can-cer cells MDA-MB231. CBD downregulated Id1 at pro-moter level and reduced tumor aggressiveness.40

Another study used xenografts to study the proapop-totic effect of CBD, this time in LNCaP prostate carci-noma cells.36 In this 5-week study, 100 mg/kg CBD wasadministered daily i.p. Tumor volume was reduced by60% and no adverse effects of treatment were describedin the study. The authors assumed that the observedantitumor effects were mediated via TRPM8 togetherwith ROS release and p53 activation.41 It has to bepointed out though, that xenograft studies only havelimited predictive validity to results with humans.Moreover, to carry out these experiments, animalsare often immunologically compromised, to avoid im-munogenic reactions as a result to implantation ofhuman cells into the animals, which in turn can alsoaffect the results.42

Another approach was chosen by Aviello et al.43

They used the carcinogen azoxymethane to inducecolon cancer in mice. Treatment occurred using IP in-jections of 1 or 5 mg/kg CBD, three times a week for 3weeks (including 1 week before carcinogen adminis-tration). After 3 months, the number of aberrantcrypt foci, polyps, and tumors was analyzed. Thehigh CBD concentration led to a significant decreasein polyps and a return to near-normal levels of phos-phorylated Akt (elevation caused by the carcino-gen).42 No adverse effects were mentioned in thedescribed study.43

Food intake and glycemic effectsAnimal studies summarized by Bergamaschi et al.showed inconclusive effects of CBD on food intake1:i.p. administration of 3–100 mg/kg b.w. had no effecton food intake in mice and rats. On the contrary, the

induction of hyperphagia by CB1 and 5HT1A agonistsin rats could be decreased with CBD (20 mg/kg b.w.i.p.). Chronic administration (14 days, 2.5 or 5 mg/kg i.p.) reduced the weight gain in rats. This effectcould be inhibited by coadministration of a CB2Rantagonist.1

The positive effects of CBD on hyperglycemia seemto be mainly mediated via CBD anti-inflammatoryand antioxidant effects. For instance, in ob/ob mice(an animal model of obesity), 4-week treatment with3 mg/kg (route of administration was not mentioned)increased the HDL-C concentration by 55% and re-duced total cholesterol levels by more than 25%. Inaddition, treatment increased adiponectin and liverglycogen concentrations.44 and references therein

Endocrine effectsHigh CBD concentrations (1 mM) inhibited progester-one 17-hydroxylase, which creates precursors for sexsteroid and glucocorticoid synthesis, whereas 100 lMCBD did not in an in vitro experiment with primarytestis microsomes.45 Rats treated with 10 mg/kgi.p. b.w. CBD showed inhibition of testosterone oxida-tion in the liver.46

Genotoxicity and mutagenicityJones et al. mention that 120 mg/kg CBD deliveredintraperetonially to Wistar Kyoto rats showed no mu-tagenicity and genotoxicity based on personal commu-nication with GW Pharmaceuticals47,48 These data areyet to be published. The 2012 study with an epilepsymouse model could also show that CBD did not influ-ence grip strength, which the study describes as a ‘‘pu-tative test for functional neurotoxicity.’’48

Motor function was also tested on a rotarod, whichwas also not affected by CBD administration. Staticbeam performance, as an indicator of sensorimotor co-ordination, showed more footslips in the CBD group,but CBD treatment did not interfere with the animals’speed and ability to complete the test. Compared toother anticonvulsant drugs, this effect was minimal.48

Unfortunately, we could not find more studies solelyfocusing on genotoxicity by other research groups nei-ther in animals nor in humans.

Acute Clinical DataBergamaschi et al. list an impressive number of acuteand chronic studies in humans, showing CBD safetyfor a wide array of side effects.1 They also concludefrom their survey, that none of the studies reported


145

tolerance to CBD. Already in the 1970s, it was shownthat oral CBD (15–160 mg), iv injection (5–30 mg),and inhalation of 0.15 mg/kg b.w. CBD did not leadto adverse effects. In addition, psychomotor functionand psychological functions were not disturbed.Treatment with up to 600 mg CBD neither influencedphysiological parameters (blood pressure, heart rate)nor performance on a verbal paired-associate learn-ing test.1

Fasinu et al. created a table with an overview of clin-ical studies currently underway, registered in ClinicalTrials. gov.49 In the following chapter, we highlight re-cent, acute clinical studies with CBD.

CBD-drug interactionsCBD can inhibit CYP2D6, which is also targeted by ome-prazole and risperidone.2,14 There are also indicationsthat CBD inhibits the hepatic enzyme CYP2C9, reduc-ing the metabolization of warfarin and diclofenac.2,14

More clinical studies are needed, to check whether thisinteraction warrants an adaption of the used doses ofthe coadministered drugs.

The antibiotic rifampicin induces CYP3A4, leading toreduced CBD peak plasma concentrations.14 In contrast,the CYP3A4 inhibitor ketoconazole, an antifungal drug,almost doubles CBD peak plasma concentration. Inter-estingly, the CYP2C19 inhibitor omeprazole, used totreat gastroesophageal reflux, could not significantly af-fect the pharmacokinetics of CBD.14

A study, where a regimen of 6 · 100 mg CBD dailywas coadministered with hexobarbital in 10 subjects,found that CBD increased the bioavailability and elim-ination half-time of the latter. Unfortunately, it was notmentioned whether this effect was mediated via the cy-tochrome P450 complex.16

Another aspect, which has not been thoroughlylooked at, to our knowledge, is that several cytochromeisozymes are not only expressed in the liver but also inthe brain. It might be interesting to research organ-specific differences in the level of CBD inhibition ofvarious isozymes. Apart from altering the bioavailabilityin the overall plasma of the patient, this interactionmight alter therapeutic outcomes on another level. Dop-amine and tyramine are metabolized by CYP2D6, andneurosteroid metabolism also occurs via the isozymesof the CYP3A subgroup.50,51 Studying CBD interactionwith neurovascular cytochrome P450 enzymes mightalso offer new mechanisms of action. It could be possiblethat CBD-mediated CYP2D6 inhibition increases dopa-mine levels in the brain, which could help to explain the

positive CBD effects in addiction/withdrawal scenariosand might support its 5HT (=serotonin) elevating effectin depression.

Also, CBD can be a substrate of UDP glucuronosyl-transferase.14 Whether this enzyme is indeed involvedin the glucuronidation of CBD and also causes clini-cally relevant drug interactions in humans is yet to bedetermined in clinical studies. Generally, morehuman studies, which monitor CBD-drug interactions,are needed.

Physiological effectsIn a double-blind, placebo-controlled crossover study,CBD was coadministered with intravenous fentanyl toa total of 17 subjects.10 Blood samples were obtainedbefore and after 400 mg CBD (previously demon-strated to decrease blood flow to (para)limbic areasrelated to drug craving) or 800 mg CBD pretreatment.This was followed by a single 0.5 (Session 1) or 1.0lg/kg(Session 2, after 1 week of first administration to allowfor sufficient drug washout) intravenous fentanyl dose.Adverse effects and safety were evaluated with bothforms of the Systematic Assessment for TreatmentEmergent Events (SAFTEE). This extensive tool tests,for example, 78 adverse effects divided into 23 catego-ries corresponding to organ systems or body parts. TheSAFTEE outcomes were similar between groups. Norespiratory depression or cardiovascular complicationswere recorded during any test session.

The results of the evaluation of pharmacokinetics, tosee if interaction between the drugs occurred, were asfollows. Peak CBD plasma concentrations of the 400and 800 mg group were measured after 4 h in the firstsession (CBD administration 2 h after light breakfast).Peak urinary CBD and its metabolite concentrationsoccurred after 6 h in the low CBD group and after 4 hin the high CBD group. No effect was evident for uri-nary CBD and metabolite excretion except at thehigher fentanyl dose, in which CBD clearance was re-duced. Importantly, fentanyl coadministration didnot produce respiratory depression or cardiovascularcomplications during the test sessions and CBD didnot potentiate fentanyl’s effects. No correlation wasfound between CBD dose and plasma cortisol levels.

Various vital signs were also measured (blood pres-sure, respiratory/heart rate, oxygen saturation, EKG,respiratory function): CBD did not worsen the adverseeffects (e.g., cardiovascular compromise, respiratorydepression) of iv fentanyl. Coadministration was safeand well tolerated, paving the way to use CBD as a


146

potential treatment for opioid addiction. The validatedsubjective measures scales Anxiety (visual analog scale[VAS]), PANAS (positive and negative subscores), andOVAS (specific opiate VAS) were administered acrosseight time points for each session without any signifi-cant main effects for CBD for any of the subjective ef-fects on mood.10

A Dutch study compared subjective adverse effectsof three different strains of medicinal cannabis, dis-tributed via pharmacies, using VAS. ‘‘Visual analogscale is one of the most frequently used psychometricinstruments to measure the extent and nature of sub-jective effects and adverse effects. The 12 adjectivesused for this study were as follows: alertness, tranquil-ity, confidence, dejection, dizziness, confusion/disori-entation, fatigue, anxiety, irritability, appetite, creativestimulation, and sociability.’’ The high CBD straincontained the following concentrations: 6% D9-THC/7.5% CBD (n = 25). This strain showed signifi-cantly lower levels of anxiety and dejection. Moreover,appetite increased less in the high CBD strain. Thebiggest observed adverse effect was ‘‘fatigue’’ with ascore of 7 (out of 10), which did not differ betweenthe three strains.52

Neurological and neurospychiatric effectsAnxiety. Forty-eight participants received subanxio-lytic levels (32 mg) of CBD, either before or after theextinction phase in a double-blind, placebo-controlleddesign of a Pavlovian fear-conditioning experiment(recall with conditioned stimulus and context after48 h and exposure to unconditioned stimulus after re-instatement). Skin conductance (=autonomic responseto conditioning) and shock expectancy measures (=ex-plicit aspects) of conditioned responding were recordedthroughout. Among other scales, the Mood RatingScale (MRS) and the Bond and Bodily SymptomsScale were used to assess anxiety, current mood, andphysical symptoms. ‘‘CBD given postextinction (activeafter consolidation phase) enhanced consolidation ofextinction learning as assessed by shock expectancy.’’Apart from the extinction-enhancing effects of CBDin human aversive conditioned memory, CBD showeda trend toward some protection against reinstatementof contextual memory. No side/adverse effects werereported.53

Psychosis. The review by Bergamaschi et al. mentionsthree acute human studies that have demonstrated theCBD antipsychotic effect without any adverse effects

being observed. This holds especially true for the extra-pyramidal motor side effects elicited by classical anti-psychotic medication.1

Fifteen male, healthy subjects with minimal priorD9-THC exposure (<15 times) were tested for CBD af-fecting D9-THC propsychotic effects using functionalmagnetic resonance imaging (fMRI) and various ques-tionnaires on three occasions, at 1-month intervals,following administration of 10 mg delta-9-D9-THC,600 mg CBD, or placebo. Order of drug administrationwas pseudorandomized across subjects, so that anequal number of subjects received any of the drugs dur-ing the first, second, or third session in a double-blind,repeated-measures, within-subject design.54 No CBD ef-fect on psychotic symptoms as measured with PANSSpositive symptoms subscale, anxiety as indexed by theState Trait Anxiety Inventory (STAI) state, and VisualAnalogue Mood Scale (VAMS) tranquilization orcalming subscale, compared to the placebo group,was observed. The same is true for a verbal learningtask (=behavioral performance of the verbal memory).

Moreover, pretreatment with CBD and subsequentD9-THC administration could reduce the latter’s psy-chotic and anxiety symptoms, as measured using astandardized scale. This effect was caused by oppositeneural activation of relevant brain areas. In addition,no effects on peripheral cardiovascular measures suchas heart rate and blood pressure were measured.54

A randomized, double-blind, crossover, placebo-controlled trial was conducted in 16 healthy non-anxious subjects using a within-subject design. OralD9-THC = 10 mg, CBD = 600 mg, or placebo was ad-ministered in three consecutive sessions at 1-monthintervals. The doses were selected to only evoke neuro-cognitive effects without causing severe toxic, physical,or psychiatric reactions. The 600 mg CBD corre-sponded to mean (standard deviation) whole blood lev-els of 0.36 (0.64), 1.62 (2.98), and 3.4 (6.42) ng/mL, 1, 2,and 3 h after administration, respectively.

Physiological measures and symptomatic effectswere assessed before, and at 1, 2, and 3 h postdrug ad-ministration using PANSS (a 30-item rating instru-ment used to assess psychotic symptoms, with ratingsbased on a semistructured clinical interview yieldingsubscores for positive, negative, and general psychopa-thology domains), the self-administered VAMS with 16items (e.g., mental sedation or intellectual impairment,physical sedation or bodily impairments, anxiety effectsand other types of feelings or attitudes), the ARCI (Addic-tion Research Center Inventory; containing empirically


147

derived drug-induced euphoria; stimulant-like effects;intellectual efficiency and energy; sedation; dysphoria;and somatic effects) to assess drug effects and theSTAI-T/S, where subjects were evaluated on their cur-rent mood and their feelings in general.

There were no significant differences between the ef-fects of CBD and placebo on positive and negative psy-chotic symptoms, general psychopathology (PANSS),anxiety (STAI-S), dysphoria (ARCI), sedation (VAMS,ARCI), and the level of subjective intoxication (ASI,ARCI), where D9-THC did have a pronounced effect.The physiological parameters, heart rate and blood pres-sure, were also monitored and no significant differencebetween the placebo and the CBD group was observed.55

Addiction. A case study describes a patient treated forcannabis withdrawal according to the following CBDregimen: ‘‘treated with oral 300 mg on Day 1; CBD600 mg on Days 2–10 (divided into two doses of300 mg), and CBD 300 mg on Day 11.’’ CBD treatmentresulted in a fast and progressive reduction in with-drawal, dissociative and anxiety symptoms, as mea-sured with the Withdrawal Discomfort Score, theMarijuana Withdrawal Symptom Checklist, BeckAnxiety Inventory, and Beck Depression Inventory(BDI). Hepatic enzymes were also measured daily,but no effect was reported.56

Naturalistic studies with smokers inhaling cannabiswith varying amounts of CBD showed that the CBDlevels were not altering psychomimetic symptoms.1

Interestingly, CBD was able to reduce the ‘‘wanting/liking’’ = implicit attentional bias caused by exposureto cannabis and food-related stimuli. CBD mightwork to alleviate disorders of addiction, by alteringthe attentive salience of drug cues. The study did notfurther measure side effects.57

CBD can also reduce heroin-seeking behaviors (e.g.,induced by a conditioned cue). This was shown in thepreclinical data mentioned earlier and was also repli-cated in a small double-blind pilot study with individu-als addicted to opioids, who have been abstinent for7 days.52,53 They either received placebo or 400 or800 mg oral CBD on three consecutive days. Cravingwas induced with a cue-induced reinstatement para-digm (1 h after CBD administration). One hour afterthe video session, subjective craving was already reducedafter a single CBD administration. The effect persistedfor 7 days after the last CBD treatment. Interestingly,anxiety measures were also reduced after treatment,whereas no adverse effects were described.23,58

A pilot study with 24 subjects was conducted in arandomized, double-blind, placebo-controlled designto evaluate the impact of the ad hoc use of CBDin smokers, who wished to stop smoking. Pre- andpost-testing for mood and craving of the participantswas executed. These tests included the BehaviourImpulsivity Scale, BDI, STAI, and the Severity ofDependence Scale. During the week of CBD inhalatoruse, subjects used a diary to log their craving (ona scale from 1 to 100 = VAS measuring momentarysubjective craving), the cigarettes smoked, and thenumber of times they used the inhaler. Craving wasassessed using the Tiffany Craving Questionnaire(11). On day 1 and 7, exhaled CO was measured totest smoking status. Sedation, depression, and anxietywere evaluated with the MRS.

Over the course of 1 week, participants used the in-haler when they felt the urge to smoke and received adose of 400 lg CBD via the inhaler (leading to >65%bioavailability); this significantly reduced the numberof cigarettes smoked by ca. 40%, while craving wasnot significantly different in the groups post-test. Atday 7, the anxiety levels for placebo and CBD groupdid not differ. CBD did not increase depression (incontract to the selective CB1 antagonist rimonabant).CBD might weaken the attentional bias to smokingcues or could have disrupted reconsolidation, therebydestabilizing drug-related memories.59

Cell migrationAccording to our literature survey, there currently areno studies about CBD role in embryogenesis/cell mi-gration in humans, even though cell migration doesplay a role in embryogenesis and CBD was shownto be able to at least influence migratory behavior incancer.1

Endocrine effects and glycemic (including appetite)effectsTo the best of our knowledge, no acute studieswere performed that solely concentrated on CBDglycemic effects. Moreover, the only acute studythat also measured CBD effect on appetite was thestudy we described above, comparing different can-nabis strains. In this study, the strain high in CBDelicited less appetite increase compared to the THC-only strain.52

Eleven healthy volunteers were treated with 300 mg(seven patients) and 600 mg (four patients) oral CBDin a double-blind, placebo-controlled study. Growth


148

hormone and prolactin levels were unchanged. In con-trast, the normal decrease of cortisol levels in the morn-ing (basal measurement = 11.0 – 3.7 lg/dl; 120 min afterplacebo = 7.1 – 3.9 lg/dl) was inhibited by CBD treat-ment (basal measurement = 10.5 – 4.9 lg/dl; 120 minafter 300 mg CBD = 9.9 – 6.2 lg/dl; 120 min after600 mg CBD = 11.6 – 11.6 lg/dl).60

A more recent study also used 600 mg oral CBD for aweek and compared 24 healthy subjects to people atrisk for psychosis (n = 32; 16 received placebo and 16CBD). Serum cortisol levels were taken before theTSST (Trier Social Stress Test), immediately after, aswell as 10 and 20 min after the test. Compared to thehealthy individuals, the cortisol levels increased lessafter TSST in the 32 at-risk individuals. The CBDgroup showed less reduced cortisol levels but differ-ences were not significant.61 It has to be mentionedthat these data were presented at a conference andare not yet published (to our knowledge) in a peer-reviewed journal.

Chronic CBD Studies in HumansTruly chronic studies with CBD are still scarce. Onecan often argue that what the studies call ‘‘chronic’’CBD administration only differs to acute treatment, be-cause of repeated administration of CBD. Nonetheless,we also included these studies with repeated CBD treat-ment, because we think that compared to a one-timedose of CBD, repeated CBD regimens add value andknowledge to the field and therefore should be men-tioned here.

CBD-drug interactionsAn 8-week-long clinical study, including 13 childrenwho were treated for epilepsy with clobazam (initial av-erage dose of 1 mg/kg b.w.) and CBD (oral; startingdose of 5 mg/kg b.w. raised to maximum of 25 mg/kgb.w.), showed the following. The CBD interactionwith isozymes CYP3A4 and CYP2C19 caused in-creased clobazam bioavailability, making it possible toreduce the dose of the antiepileptic drug, which inturn reduced its side effects.62

These results are supported by another study de-scribed in the review by Grotenhermen et al.63 In thisstudy, 33 children were treated with a daily doseof 5 mg/kg CBD, which was increased every weekby 5 mg/kg increments, up to a maximum level of25 mg/kg. CBD was administered on average withthree other drugs, including clobazam (54.5%), val-proic acid (36.4%), levetiracetam (30.3%), felbamate

(21.2%), lamotrigine (18.2%), and zonisamide(18.2%). The coadministration led to an alteration ofblood levels of several antiepileptic drugs. In the caseof clobazam this led to sedation, and its levels were sub-sequently lowered in the course of the study.

Physiological effectsA first pilot study in healthy volunteers in 1973 by Min-cis et al. administering 10 mg oral CBD for 21 days didnot find any neurological and clinical changes (EEG;EKG).64 The same holds true for psychiatry andblood and urine examinations. A similar testing batterywas performed in 1980, at weekly intervals for 30 dayswith daily oral CBD administration of 3 mg/kg b.w.,which had the same result.65

Neurological and neuropsychiatric effectsAnxiety. Clinical chronic (lasting longer than a coupleof weeks) studies in humans are crucial here but weremostly still lacking at the time of writing this review.They hopefully will shed light on the inconsistenciesobserverd in animal studies. Chronic studies in humansmay, for instance, help to test whether, for example, ananxiolytic effect always prevails after chronic CBD treat-ment or whether this was an artifact of using differentanimal models of anxiety or depression.2,18

Psychosis and bipolar disorder. In a 4-week opentrial, CBD was tested on Parkinson’s patients with psy-chotic symptoms. Oral doses of 150–400 mg/day CBD(in the last week) were administered. This led to a re-duction of their psychotic symptoms. Moreover, no se-rious side effects or cognitive and motor symptomswere reported.66

Bergamaschi et al. describe a chronic study, where ateenager with severe side effects of traditional antipsy-chotics was treated with up to 1500 mg/day of CBD for4 weeks. No adverse effects were observed and hersymptoms improved. The same positive outcome wasregistered in another study described by Bergamaschiet al., where three patients were treated with a startingdose of CBD of 40 mg, which was ramped up to1280 mg/day for 4 weeks.1 A double-blind, randomizedclinical trial of CBD versus amisulpride, a potent anti-psychotic in acute schizophrenia, was performed on atotal of 42 subjects, who were treated for 28 days start-ing with 200 mg CBD per day each.67 The dose was in-creased stepwise by 200 mg per day to 4 · 200 mgCBD daily (total 800 mg per day) within the firstweek. The respective treatment was maintained for


149

three additional weeks. A reduction of each treatmentto 600 mg per day was allowed for clinical reasons,such as unwanted side effects after week 2. This wasthe case for three patients in the CBD group and fivepatients in the amisulpride group. While both treat-ments were effective (no significant difference inPANSS total score), CBD showed the better side effectprofile. Amisulpride, working as a dopamine D2/D3-receptor antagonist, is one of the most effective treat-ment options for schizophrenia. CBD treatment wasaccompanied by a substantial increase in serum anan-damide levels, which was significantly associated withclinical improvement, suggesting inhibition of ananda-mide deactivation via reduced FAAH activity.

In addition, the FAAH substrates palmitoylethano-lamide and linoleoyl-ethanolamide (both lipid media-tors) were also elevated in the CBD group. CBDshowed less serum prolactin increase (predictor of gal-actorrhoea and sexual dysfunction), fewer extrapyra-midal symptoms measured with the ExtrapyramidalSymptom Scale, and less weight gain. Moreover, elec-trocardiograms as well as routine blood parameterswere other parameters whose effects were measuredbut not reported in the study. CBD better safety profilemight improve acute compliance and long-term treat-ment adherence.67,68

A press release by GW Pharmaceuticals of Septem-ber 15th, 2015, described 88 patients with treatment-resistant schizophrenic psychosis, treated either withCBD (in addition to their regular medication) or pla-cebo. Important clinical parameters improved in theCBD group and the number of mild side effects wascomparable to the placebo group.2 Table 2 shows anoverview of studies with CBD for the treatment of psy-

chotic symptoms and its positive effect on symptom-atology and the absence of side effects.69

Treatment of two patients for 24 days with 600–1200 mg/day CBD, who were suffering from BD, didnot lead to side effects.70 Apart from the study withtwo patients mentioned above, CBD has not beentested systematically in acute or chronic administrationscenarios in humans for BD according to our own lit-erature search.71

Epilepsy. Epileptic patients were treated for 135 dayswith 200–300 mg oral CBD daily and evaluated everyweek for changes in urine and blood. Moreover, neuro-logical and physiological examinations were per-formed, which neither showed signs of CBD toxicitynor severe side effects. The study also illustrated thatCBD was well tolerated.65

A review by Grotenhermen and Muller-Vahl de-scribes several clinical studies with CBD2: 23 patientswith therapy-resistant epilepsy (e.g., Dravet syndrome)were treated for 3 months with increasing doses of upto 25 mg/kg b.w. CBD in addition to their regular epi-lepsy medication. Apart from reducing the seizure fre-quency in 39% of the patients, the side effects were onlymild to moderate and included reduced/increased ap-petite, weight gain/loss, and tiredness.

Another clinical study lasting at least 3 months with137 children and young adults with various forms ofepilepsy, who were treated with the CBD drug Epi-diolex, was presented at the American Academy forNeurology in 2015. The patients were suffering fromDravet syndrome (16%), Lennox–Gastaut syndrome(16%), and 10 other forms of epilepsy (some amongthem were very rare conditions). In this study, almost

Table 2. Studies with CBD with Patients with Psychotic Symptoms (Adapted)69

Assessment Oral CBD administration

Total numberof study

participants Main findings

BPRS (brief psychiatricrating scale)

Up to 1500 mg/day for 26 days 1 Improvement of symptomatology, no side effects

BPRS Up to 1280 mg/day for 4 weeks 3 Mild improvement of symptomatology of 1 patient,no side effects

BPRS, Parkinson PsychosisQuestionnaire (PPQ)

Up to 600 mg/day for 4 weeks 6 Improvement of symptomatology, no side effects

Stroop Color Word Test,BPRS, PANSS (positive andnegative symptom scale)

Single doses of 300 or 600 mg 28 Performance after placebo and CBD 300 mg comparedto CBD 600 mg; no effects on symptomatology

BPRS, PANSS Up to 800 mg/day for 4 weeks 39 CBD as effective as amisulpride in terms of improvementof symptomatology; CBD displayed superior sideeffect profile


150

50% of the patients experienced a reduction of seizurefrequency. The reported side effects were 21% experi-enced tiredness, 17% diarrhea, and 16% reduced appe-tite. In a few cases, severe side effects occurred, but itis not clear, if these were caused by Epidiolex. Thesewere status epilepticus (n = 10), diarrhea (n = 3),weight loss (n = 2), and liver damage in one case.

The largest CBD study conducted thus far was anopen-label study with Epidiolex in 261 patients (mainlychildren, the average age of the participants was 11)suffering from severe epilepsy, who could not be trea-ted sufficiently with standard medication. After 3months of treatment, where patients received CBD to-gether with their regular medication, a median reduc-tion of seizure frequency of 45% was observed. Tenpercent of the patients reported side effects (tiredness,diarrhea, and exhaustion).2

After extensive literature study of the available trialsperformed until September 2016, CBD side effects weregenerally mild and infrequent. The only exceptionseems to be a multicenter open-label study with atotal of 162 patients aged 1–30 years, with treatment-resistant epilepsy. Subjects were treated for 1 yearwith a maximum of 25 mg/kg (in some clinics 50 mg/kg) oral CBD, in addition to their standard medication.

This led to a reduction in seizure frequency. In thisstudy, 79% of the cohort experienced side effects. Thethree most common adverse effects were somnolence(n = 41 [25%]), decreased appetite (n = 31 [19%]), anddiarrhea (n = 31 [19%]).72 It has to be pointed outthat no control group existed in this study (e.g., placeboor another drug). It is therefore difficult to put the sideeffect frequency into perspective. Attributing the sideeffects to CBD is also not straightforward in severelysick patients. Thus, it is not possible to draw reliableconclusions on the causation of the observed side ef-fects in this study.

Parkinson’s disease. In a study with a total of 21 Par-kinson’s patients (without comorbid psychiatric condi-tions or dementia) who were treated with eitherplacebo, 75 mg/day CBD or 300 mg/day CBD in an ex-ploratory double-blind trial for 6 weeks, the higherCBD dose showed significant improvement of qualityof life, as measured with PDQ-39. This rating instru-ment comprised the following factors: mobility, activi-ties of daily living, emotional well-being, stigma, socialsupport, cognition, communication, and bodily dis-comfort. For the factor, ‘‘activities of daily living,’’ apossible dose-dependent relationship could exist be-

tween the low and high CBD group—the two CBDgroups scored significantly different here. Side effectswere evaluated with the UKU (Udvalg for KliniskeUndersøgelser). This assessment instrument analyzesadverse medication effects, including psychic, neuro-logic, autonomic, and other manifestations. Using theUKU and verbal reports, no significant side effectswere recognized in any of the CBD groups.73

Huntington’s disease. Fifteen neuroleptic-free pa-tients with Huntington’s disease were treated with ei-ther placebo or oral CBD (10 mg/kg b.w. per day) for6 weeks in a double-blind, randomized, crossoverstudy design. Using various safety outcome variables,clinical tests, and the cannabis side effect inventory, itwas shown that there were no differences between theplacebo group and the CBD group in the observedside effects.6

Immune systemForty-eight patients were treated with 300 mg/kg oralCBD, 7 days before and until 30 days after the trans-plantation of allogeneic hematopoietic cells from anunrelated donor to treat acute leukemia or myelodys-plastic syndrome in combination with standard mea-sures to avoid GVHD (graft vs. host disease;cyclosporine and short course of MTX). The occur-rence of various degrees of GVHD was comparedwith historical data from 108 patients, who had only re-ceived the standard treatment. Patients treated withCBD did not develop acute GVHD. In the 16 monthsafter transplantation, the incidence of GHVD was sig-nificantly reduced in the CBD group. Side effects weregraded using the Common Terminology Criteria forAdverse Events (CTCAE v4.0) classification, whichdid not detect severe adverse effects.74

Endocrine and glycemic (including appetite, weightgain) effectsIn a placebo-controlled, randomized, double-blindstudy with 62 subjects with noninsulin-treated type 2diabetes, 13 patients were treated with twice-dailyoral doses of 100 mg CBD for 13 weeks. This resultedin lower resistin levels compared to baseline. The hor-mone resistin is associated with obesity and insulin re-sistance. Compared to baseline, glucose-dependentinsulinotropic peptide levels were elevated after CBDtreatment. This incretin hormone is produced in theproximal duodenum by K cells and has insulinotropicand pancreatic b cell preserving effects. CBD was well


151

tolerated in the patients. However, with the compara-tively low CBD concentrations used in this phase-2-trial, no overall improvement of glycemic control wasobserved.40

When weight and appetite were measured as part of ameasurement battery for side effects, results were incon-clusive. For instance, the study mentioned above, where23 children with Dravet syndrome were treated, in-creases as well as decreases in appetite and weightwere observed as side effects.2 An open-label trial with214 patients suffering from treatment-resistant epilepsyshowed decreased appetite in 32 cases. However, in thesafety analysis group, consisting of 162 subjects, 10showed decreased weight and 12 had gained weight.52

This could be either due to the fact that CBD only hasa small effect on these factors, or appetite and weightare complex endpoints influenced by multiple factorssuch as diet and genetic predisposition. Both these fac-tors were not controlled for in the reviewed studies.

ConclusionThis review could substantiate and expand the findingsof Bergamaschi et al. about CBD favorable safety pro-file.1 Nonetheless, various areas of CBD researchshould be extended. First, more studies researchingCBD side effects after real chronic administrationneed to be conducted. Many so-called chronic admin-istration studies, cited here were only a couple of weekslong. Second, many trials were conducted with a smallnumber of individuals only. To perform a throroughgeneral safety evaluation, more individuals have to berecruited into future clinical trials. Third, several as-pects of a toxicological evaluation of a compoundsuch as genotoxicity studies and research evaluatingCBD effect on hormones are still scarce. Especially,chronic studies on CBD effect on, for example, geno-toxicity and the immune system are still missing.Last, studies that evaluate whether CBD-drug interac-tions occur in clinical trials have to be performed.

In conclusion, CBD safety profile is already estab-lished in a plethora of ways. However, some knowledgegaps detailed above should be closed by additional clin-ical trials to have a completely well-tested pharmaceu-tical compound.

AcknowledgmentsThe study was commissioned by the European IndustrialHemp Association. The authors thank Michal Carus,Executive Director of the EIHA, for making this reviewpossible, for his encouragement, and helpful hints.

Author Disclosure StatementEIHA paid nova-Institute for the review. F.G. is Exec-utive Director of IACM.

References1. Bergamaschi MM, Queiroz RH, Zuardi AW, et al. Safety and side effects

of cannabidiol, a Cannabis sativa constituent. Curr Drug Saf. 2011;6:237–249.

2. Grotenhermen F, Muller-Vahl K. Cannabis und Cannabinoide in derMedizin: Fakten und Ausblick. Suchttherapie. 2016;17:71–76.

3. Hampson AJ, Grimaldi M, Axelrod J, et al. Cannabidiol and D9-tetrahydrocannabinol are neuroprotective antioxidants. PNAS.1998;95:8268–8273.

4. Olah A, Toth BI, Borbıro I, et al. Cannabidiol exerts sebostatic andantiinflammatory effects on human sebocytes. J Clin Invest.2014:124:3713.

5. Deiana S, Watanabe A, Yamasaki Y, et al. Plasma and brain pharmacoki-netic profile of Cannabidiol (CBD), cannabidivarine (CBDV), Delta (9)-tetrahydrocannabivarin (D9-THCV) and cannabigerol (CBG) in rats andmice following oral and intraperitoneal administration and CBD action onobsessive compulsive behaviour. Psychopharmacology. 2012;219:859–873.

6. Consroe P, Laguna J, Allender J, et al. Controlled clinical trial of canna-bidiol in Huntington’s disease. Pharmacol Biochem Beh. 1991;40:701–708.

7. Bih CI, Chen T, Nunn AV, et al. Molecular targets of cannabidiol in neu-rological disorders. Neurotherapeutics. 2015;12:699–730.

8. Stout SM, Cimino NM. Exogenous cannabinoids as substrates, inhibitors,and inducers of human drug metabolizing enzymes: a systematic review.Drug Metab Rev. 2014;46:86–95.

9. Fusar-Poli P, Crippa JA, Bhattacharyya S, et al. Distinct effects of D9-tetrahydro-cannabinoland cannabidiol on neural activation during emo-tional processing. Arch Gen Psychiat. 2009;66:95.

10. Manini AF, Yiannoulos G, Bergamaschi MM, et al. Safety andpharmacokinetics of oral cannabidiol when administered concomi-tantly with intravenous fentanyl in humans. J Addict Med. 2014;9:204–210.

11. Monographie NN. Cannabidiol. Deutscher Arzneimittel-Codex (DAC) inkl.Neues Rezeptur-Formularium (NRF). DAC/NRF October 22, 2015.

12. Pelkonen O, Maeenpaea J, Taavitsainen P, et al. Inhibition and inductionof human cytochrome P450 (CYP) enzymes. Xenobiotica. 1998;28:1203–1253.

13. Karlgren M, Bergstrom CA. How physicochemical properties of drugsaffect their metabolism and clearance. In: New horizons in predictivedrug metabolism and pharmacokinetics. Royal Society of Chemistry:Cambridge, UK, 2015.

14. Ujvary I, Hanus L. Human metabolites of cannabidiol: a review on theirformation, biological activity, and relevance in therapy. Cannabis Can-nabinoid Res. 2016;1:90–101.

15. Bornheim LM, Everhart ET, Li J, et al. Induction and genetic regulation ofmouse hepatic cytochrome P450 by cannabidiol. Biochem Pharmacol.1994;48:161–171.

16. Brzozowska N, Li KM, Wang XS, et al. ABC transporters P-gp and Bcrpdo not limit the brain uptake of the novel antipsychotic and anti-convulsant drug cannabidiol in mice. Peer J. 2016;4:e2081.

17. Feinshtein V, Erez O, Ben-Zvi Z, et al. Cannabidiol enhances xenobioticpermeability through the human placental barrier by direct inhibition ofbreast cancer resistance protein: an ex vivo study. Am J Obstet Gynecol.2013;209:573-e1.

18. Linge R, Jimenez-Sanchez L, Campa L, et al. Cannabidiol induces rapid-acting antidepressant-like effects and enhances cortical 5-HT/glutamateneurotransmission: role of 5-HT 1A receptors. Neuropharmacology.2016;103:16–26.

19. Schiavon AP, Bonato JM, Milani H, et al. Influence of single and repeatedcannabidiol administration on emotional behavior and markers of cellproliferation and neurogenesis in non-stressed mice. Prog Neuropsy-chopharmacol. 2016;64:27–34.

20. Peres FF, Levin R, Almeida V, et al. Cannabidiol, among other cannabinoiddrugs, modulates prepulse inhibition of startle in the SHR animal model:


152

implications for schizophrenia pharmacotherapy. Front Pharmacol.2016;7:303.

21. Gomes FV, Issy AC, Ferreira FR, et al. Cannabidiol attenuates sensori-motor gating disruption and molecular changes induced by chronicantagonism of NMDA receptors in mice. J Neuropsychopharmacol.2015;18:pyu041.

22. Valvassori SS, Elias G, de Souza B, et al. Effects of cannabidiol onamphetamine-induced oxidative stress generation in an animal model ofmania. J Psychopharmacol. 2011;25:274–280.

23. Ren Y, Whittard J, Higuera-Matas A, et al. Cannabidiol, a nonpsychotropiccomponent of cannabis, inhibits cue-induced heroin seeking and nor-malizes discrete mesolimbic neuronal disturbances. J Neurosci.2009;29:14764–14769.

24. Sun S, Hu F, Wu J, Zhang S. Cannabidiol attenuates OGD/R-induceddamage by enhancing mitochondrial bioenergetics and modulatingglucose metabolism via pentose-phosphate pathway in hippocampalneurons. Redox Biol. 2017;11:577–585.

25. Schurr A, Livne A. Differential inhibition of mitochondrial monoamineoxidase from brain by hashish components. Biochem Pharmacol.1976;25:1201–1203.

26. Alvarez FJ, Lafuente H, Rey-Santano MC. Neuroprotective effects of thenonpsychoactive cannabinoid cannabidiol in hypoxicischemic newbornpiglets. Pediatr Res. 2008;64:653–658.

27. Valvassori SS, Bavaresco DV, Scaini G. Acute and chronic administra-tion of cannabidiol increases mitochondrial complex and creatinekinase activity in the rat brain. Rev Bras Psiquiatr. 2013;35:380–386.

28. Scott KA, Dennis, JL, Dalgleish AG, et al. Inhibiting heat shock proteins canpotentiate the cytotoxic effect of cannabidiol in human glioma cells.Anticancer Res. 2015;35:5827–5837.

29. Burstein S. Cannabidiol (CBD) and its analogs: a review of their effects oninflammation. Bioorg Med Chem. 2015;23:1377–1385.

30. McAllister SD, Soroceanu L, Desprez PY. The antitumor activity of plant-derived non-psychoactive cannabinoids. J Neuroimmune Pharmacol.2015;10:255–267.

31. Cheng D, Spiro AS, Jenner AM, et al. Long-term cannabidiol treatmentprevents the development of social recognition memory deficits inAlzheimer’s disease transgenic mice. J Alzheimers Dis. 2014;42:1383–1396.

32. Weiss L, Zeira M, Reich S, et al. Cannabidiol arrests onset of autoimmunediabetes in NOD mice. Neuropharmacology. 2008;54:244–249.

33. Hammell DC, Zhang LP, Ma F, et al. Transdermal cannabidiol reducesinflammation and pain-related behaviours in a rat model of arthritis. Eur JPain. 2015;20:936–948.

34. Murase R, Limbad C, Murase R. Id-1 gene and protein as novel therapeutictargets for metastatic cancer. Cancer Res. 2012;72:5308.

35. Paria, BC, Das SK, Dey SK. The preimplantation mouse embryo is atarget for cannabinoid ligand-receptor signaling. PNAS. 1995;92:9460–9464.

36. Leanza L, Manago A, Zoratti M, et al. Pharmacological targeting of ionchannels for cancer therapy: in vivo evidences. Biochim Biophys Acta.2016;1863:1385–1397.

37. Ramer R, Merkord J, Rohde H, et al. Cannabidiol inhibits cancer cell in-vasion via upregulation of tissue inhibitor of matrix metalloproteinases-1.Biochem Pharmacol. 2010;79:955–966.

38. Ramer R, Bublitz K, Freimuth N. Cannabidiol inhibits lung cancer cell in-vasion and metastasis via intercellular adhesion molecule-1. FASEB J.2012;26:1535–1548.

39. Benhamou Y. Gene and protein as novel therapeutic targets for meta-static cancer. Available at www.marschallplan.at (accessed on October 1,2016).

40. McAllister SD, Christian RT, Horowitz MP. Cannabidiol as a novel inhibitorof Id-1 gene expression in aggressive breast cancer cells. Mol Cancer Ther.2007;6:2921–2927.

41. De Petrocellis L, Ligresti A, Schiano Moriello A, et al. Non-D9-THC can-nabinoids inhibit prostate carcinoma growth in vitro and in vivo: pro-apoptotic effects and underlying mechanisms. Br J Pharmacol.2013;168:79–102.

42. Fowler CJ. Delta9-tetrahydrocannabinol and cannabidiol as potentialcurative agents for cancer: a critical examination of the preclinical liter-ature. Pharmacol Ther. 2015;97:587–596.

43. Aviello G, Romano B, Borrelli F, et al. Chemopreventive effect of the non-psychotropic phytocannabinoid cannabidiol on experimental coloncancer. J Mol Med. 2012;90:925–934.

44. Jadoon KA, Ratcliffe SH, Barrett DA. Efficacy and safety of cannabidiol andtetrahydrocannabivarin on glycemic and lipid parameters in patientswith type 2 diabetes: a randomized, double-blind, placebo-controlled,parallel group pilot study. Diabetes Care. 2016;39:1777–1786.

45. Watanabe K, Motoya E, Matsuzawa N, et al. Marijuana extracts possess theeffects like the endocrine disrupting chemicals. Toxicology.2005;206:471–478.

46. Narimatsu S, Watanabe K, Yamamoto I. Inhibition of hepatic microsomalcytochrome P450 by cannabidiol in adult male rats. Chem Pharm Bull.1990;38:1365–1368.

47. Jones NA, Hill AJ, Smith I, et al. Cannabidiol displays antiepileptiform andantiseizure properties in vitro and in vivo. J Pharm Ex Ther. 2010;332:569–577.

48. Jones NA, Glyn SE, Akiyama S, et al. Cannabidiol exerts anti-convulsanteffects in animal models of temporal lobe and partial seizures. Seizure.2012;21:344–352.

49. Fasinu PS, Phillips S, ElSohly MA, et al. Current status and prospects forcannabidiol preparations as new therapeutic agents. Pharmacotherapy.2016;36:781–796.

50. Persson A, Ingelman-Sundberg M. Pharmacogenomics of cytochromeP450 dependent metabolism of endogenous compounds: implicationsfor behavior, psychopathology and treatment. J PharmacogenomicsPharmacoproteomics 2014;5:127.

51. Ghosh C, Hossain M, Solanki J, et al. Pathophysiological implications ofneurovascular P450 in brain disorders. Drug Discov Today. 2016;21:1609–1619.

52. Brunt TM, van Genugten M, Honer-Snoeken K, et al. Therapeutic satis-faction and subjective effects of different strains of pharmaceutical-gradecannabis. J Clin Psychopharmacol. 2014;34:344–349.

53. Das RK, Kamboj SK, Ramadas M, et al. Cannabidiol enhances consolida-tion of explicit fear extinction in humans. Psychopharmacology.2013;226:781–792.

54. Bhattacharyya S, Morrison PD, Fusar-Poli P, et al. Opposite effects ofD-9-tetrahydrocannabinol and cannabidiol on human brain functionand psychopathology. Neuropsychopharmacology. 2010;35:764–774.

55. Martin-Santos R, Crippa J, Batalla A. Acute effects of a single, oraldose of d9-tetrahydrocannabinol (D9-THC) and cannabidiol (CBD)administration in healthy volunteers. Curr Pharm Des. 2012;18:4966–4979.

56. Crippa JAS, Hallak JEC, Machado-de-Sousa JP, et al. Cannabidiol for thetreatment of cannabis withdrawal syndrome: a case report. J Clin PharmTher. 2013;38:162–164.

57. Morgan CJ, Freeman TP, Schafer GL. Cannabidiol attenuates theappetitive effects of D9-tetrahydrocannabinol in humans smokingtheir chosen cannabis. Neuropsychopharmacology. 2010;35:1879–1885.

58. Hurd YL, Yoon M, Manini AF. Early phase in the development of canna-bidiol as a treatment for addiction: opioid relapse takes initial centerstage. Neurotherapeutics. 2015;12:807–815.

59. Morgan CJ, Das RK, Joye A, et al. Cannabidiol reduces cigarette con-sumption in tobacco smokers: preliminary findings. Addictive Behav.2013;38:2433–2436.

60. Zuardi AW, Guimaraes FS, Moreira AC. Effect of cannabidiol on plasmaprolactin, growth hormone and cortisol in human volunteers. Braz J MedBiol Res. 1993;26:213–217.

61. Appiah-Kusi E, Mondelli V, McGuire P, et al. Effects of cannabidioltreatment on cortisol response to social stress in subjects at high riskof developing psychosis. Psychoneuroendocrinology. 2016;7(Supplement):23–24.

62. Geffrey AL, Pollack SF, Bruno PL, et al. Drug–drug interaction betweenclobazam and cannabidiol in children with refractory epilepsy. Epilepsia.2015;56:1246–1251.

63. Grotenhermen F, Gebhardt K, Berger M. Cannabidiol. NachtschattenVerlag: Solothurn, Switzerland, 2016.

64. Mincis M, Pfeferman A, Guimaraes RX. Chronic administration ofcannabidiol in man. Pilot study. AMB Rev Assoc Med Bras. 1973;19:185–190.

65. Cunha J, Carlini EA, Pereira AE, et al. Chronic administration of cannabidiolto healthy volunteers and epileptic patients. Pharmacology. 1980;21:175–185.


153

66. Zuardi AW, Crippa JAS, Hallak JEC, et al. Cannabidiol for the treatmentof psychosis in Parkinson’s disease. J Psychopharmacol. 2009;3:979–983.

67. Leweke FM, Piomelli D, Pahlisch F. Cannabidiol enhances anandamidesignaling and alleviates psychotic symptoms of schizophrenia. Translpsychiatry. 2012;2:e94.

68. Leweke F, Koethe D, Gerth C. Cannabidiol as an antipsychotic: a double-blind, controlled clinical trial of cannabidiol versus amisulpiride in acuteschizophrenia. In: 15th annual symposium on cannabinoids. CannabinoidResearch Society: Clearwater Beach, FL, 2005.

69. Iseger TA, Bossong MG. A systematic review of the antipsychoticproperties of cannabidiol in humans. Schizophr Res. 2015;162:153–161.

70. Zuardi AW, Crippa JAS, Dursun SM, et al. Cannabidiol was ineffective formanic episode of bipolar affective disorder. J Psychopharmacol.2010;24:135–137.

71. Braga RJ, Abdelmessih S, Tseng J, et al. Cannabinoids and bipolardisorder. Cannabinoids in neurologic and mental disease. Elsevier,Amsterdam, 2015, p. 205.

72. Devinsky O, Marsh E, Friedman D, et al. Cannabidiol in patients withtreatment-resistant epilepsy: an open-label interventional trial. LancetNeurol. 2016;15:270–278.

73. Chagas MHN, Zuardi AW, Tumas V, et al. Effects of cannabidiol in thetreatment of patients with Parkinson’s disease: an exploratory double-blind trial. J Psychopharmacol. 2014;28:1088–1098.

74. Yeshurun M, Shpilberg O, Herscovici C, et al. Cannabidiol for the pre-vention of graft-versus- host-disease after allogeneic hematopoietic celltransplantation: results of a phase II study. Biol Blood Marrow Transplant.2015;21:1770–1775.

Cite this article: Iffland K, Grotenhermen F (2017) An update onsafety and side effects of cannabidiol: a review of clinical data andrelevant animal studies, Cannabis and Cannabinoid Research 2:1,139–154, DOI: 10.1089/can.2016.0034.

Abbreviations UsedAD¼Alzheimer’s disease

ARCI¼Addiction Research Center InventoryBD¼ bipolar disorder

BDI¼ Beck Depression InventoryCBD¼ cannabidiolHSP¼ heat shock protein

IL¼ interleukinMRS¼Mood Rating Scale

PPI¼ prepulse inhibitionROS¼ reactive oxygen species

SAFTEE¼ Systematic Assessment for Treatment Emergent EventsSTAI¼ State Trait Anxiety InventoryTSST¼ Trier Social Stress TestUKU¼Udvalg for Kliniske Undersøgelser

VAMS¼ Visual Analogue Mood ScaleVAS¼ Visual Analog Scales

Publish in Cannabis and Cannabinoid Research

- Immediate, unrestricted online access- Rigorous peer review- Compliance with open access mandates- Authors retain copyright- Highly indexed- Targeted email marketing

liebertpub.com/can


154

http://www.liebertpub.com/can#utm_campaign=can&utm_medium=article&utm_source=advert

Exhibit B

Current Drug Safety, 2011, 6, 000-000 1

1574-8863/11 $58.00+.00 © 2011 Bentham Science Publishers

Safety and Side Effects of Cannabidiol, a Cannabis sativa Constituent

Mateus Machado Bergamaschi1,2

, Regina Helena Costa Queiroz1, José Alexandre S. Crippa

*,2 and

Antonio Waldo Zuardi2

1Department of Clinical, Toxicological and Food Sciences Analysis, School of Pharmaceutical Sciences of Ribeirão

Preto, University of São Paulo, SP, Brazil

2Department of Neuroscience and Behavior, School of Medicine, University of São Paulo and National Institute of

Translational Medicine (INCT-TM, CNPq) Ribeirão Preto, São Paulo, Brazil

Abstract: Cannabidiol (CBD), a major nonpsychotropic constituent of Cannabis, has multiple pharmacological actions,

including anxiolytic, antipsychotic, antiemetic and anti-inflammatory properties. However, little is known about its safety

and side effect profile in animals and humans. This review describes in vivo and in vitro reports of CBD administration

across a wide range of concentrations, based on reports retrieved from Web of Science, Scielo and Medline. The

keywords searched were “cannabinoids”, “cannabidiol” and “side effects”. Several studies suggest that CBD is non-toxic

in non-transformed cells and does not induce changes on food intake, does not induce catalepsy, does not affect

physiological parameters (heart rate, blood pressure and body temperature), does not affect gastrointestinal transit and

does not alter psychomotor or psychological functions. Also, chronic use and high doses up to 1,500 mg/day of CBD are

reportedly well tolerated in humans. Conversely, some studies reported that this cannabinoid can induce some side effects,

including inhibition of hepatic drug metabolism, alterations of in vitro cell viability, decreased fertilization capacity, and

decreased activities of p-glycoprotein and other drug transporters. Based on recent advances in cannabinoid administration

in humans, controlled CBD may be safe in humans and animals. However, further studies are needed to clarify these

reported in vitro and in vivo side effects.

Keywords: Cannabidiol, cannabinoid, cannabis sativa, CBD, marijuana, safety, side effects, toxicity.

INTRODUCTION

Cannabidiol (CBD) is a component of Cannabis sativa and constitutes up to 40% of the extracts of the plant [1]. However, CBD concentrations are highly variable and depend on the growing conditions, the different phenotypes of illicit cannabis, and on the part of the plant analyzed [2][3]. Evidence suggests that the potency of CBD has decreased in recent years, while THC concentrations have increased, since the use of varieties such as sensimillia (‘skunk’), provided by ilegal cannabis growers, currently dominates the supply of cannabis in many countries [3].

CBD induces markedly different psychological effects compared to the best known marijuana compound, �9-tetrahydrocannabinol (THC) [4][5]. Despite presenting low affinity for CB1 and CB2 receptors, CBD can still interact with these receptors at doses equal to or lower than 1 μM. Therefore, there is no certainty about whether this antagonism is non-competitive. CBD can also act as a CB1 receptor inverse agonist at concentrations below those needed to bind to the CB1 orthosteric site. Moreover, CBD can antagonize THC effects via non-CB1/CB2 receptors, such as GPR55, which is activated by THC and blocked by CBD [6]. The time between the intake of CBD and THC, as well as the CBD/THC ratio, seem to play an important role

*Address correspondence to this author at the Departamento de

Neurociências e Ciências do Comportamento, Faculdade de Medicina de

Ribeirão Preto, Universidade de São Paulo, Hospital das Clínicas - Terceiro

Andar, Av. Bandeirantes, 3900, Ribeirão Preto, ZIP Code: 14049-900, São

Paulo, Brazil; Tel: +55 16 36022703; Fax: +55 16 36020713; E-mail:

[email protected]

in the interaction between these two cannabinoids. CBD can increase the potency of THC by pharmacokinetic interaction if CBD is administrated before THC, or a pharmacodynamic interaction may occur when both cannabinoids are taken together, mainly at a high dose ratio of CBD/THC [7].

CBD was first isolated by Adams et al. in 1940 [8], and its structure was identified 23 years later [9]. Since then, a considerable number of published articles have dealt with its chemistry, biochemistry, pharmacology and clinical effects. By the year 2000, the primary research topics regarding possible therapeutic effects of CBD were related to its antiepileptic, sedative, anxiolytic and antipsychotic activities [10][11]. The last decade has shown a notable increase in scientific literature on CBD, owing to the identification of its anti-inflammatory and neuroprotective effects. These studies have raised the possibility of therapeutic effects of CBD for diverse conditions, including dementias, cerebral ischemia, diabetes, inflammatory diseases, nausea and psychiatric disorders [12].

� � ��

��

�� 1 and CB2 receptors, CBD is capable of antagonizing CB1 / CB2 receptor agonists at reasonably low concentrations. At CB2 receptors, CBD acts as an inverse agonist. Other mechanisms of action include antagonism of the recently discovered GPR55 receptor; transient receptor potential vanilloid type 1 (TRPV1) agonism; transient receptor potential vanilloid type 2 (TRPV2) agonism; 5-HT1A agonism; antagonism of the putative abnormal-CBD receptor; and regulation of intracellular [Ca

2+] [13].

2 Current Drug Safety, 2011, Vol. 6, No. 4 Bergamaschi et al.

Inhibition of adenosine uptake leads to increased adenosine signaling, which may explain the ability of CBD to decrease inflammation and to present neuroprotective effects [14][15]. Another similar mechanism has also been reported for CBD, according to which this cannabinoid could block anandamide uptake and inhibit its enzymatic hydrolysis [16].

Few studies have been completed concerning the safety and side effects of CBD after its administration in vivo and in vitro, but this review will summarize such findings. First, CBD safety in animals and humans will be discussed. Second, side effects of CBD intake will be discussed, as well as the biological parameters affected by CBD interaction with other substances. Finally, some toxicology aspect studied in monkey will be shown.

METHOD

This review was conducted using reports retrieved from Web of Science, Scielo and Medline. The keywords searched were “cannabinoids”, “cannabidiol” and “side effects.” No time limits were imposed on the search criteria.

We included papers in English, Portuguese and Spanish languages that described research in humans or animals using CBD alone. The reference lists of eligible papers were checked for additional relevant studies. Studies describing mixed cannabinoids or CBD extracts were excluded. A total of 132 papers were selected for the review.

RESULTS

Safety of CBD

Effect on Cell Growth and Embryogenesis

CBD exerts anti-proliferative and pro-apoptotic effects in tumor cell lines. There are several mechanisms by which CBD exhibits its effects, including the production of reactive oxygen species (ROS) and concomitant activation of initiator caspase-8 and caspase-9 [17], inhibition of the procarcinogenic lipoxygenase pathway [18], and induction of apoptosis, inhibition of tumor grown [16].

In order to investigate the selectivity of CBD’s effects in tumoral and nontumoral cells, several concentrations of CBD (1-25�M) were tested in vitro on different stabilized nontumor cell lines, such as human keratinocyte, rat preadipocytes, and mouse monocytemacrophages. CBD does not affect the vitality of nontumor cell lines, contrary to what occurs with human breast carcinoma cells, human prostate carcinoma cells, human colorectal carcinoma cells, human gastric adenocarcinoma cells, rat glioma cells, rat thyroid cells transformed with the v-K-ras oncogene, and rat basophilic leukemia cells [16]. Glial cells were also tested against CBD toxicity and their viability was not affected by the treatment with CBD up to 50μM. The safety of CBD on non-transformed cells may be explained by the lack of ROS damage in glial cells [17].

Analysis of CBD’s effects on embryo development is also important, because it raises the question whether expectant mothers can take CBD, and, consequently, whether it affects fetal development. In vitro results revealed

that CBD did not significantly alter embryonic development at concentrations of 6.4, 32 and 160 nM [19].

Effect on Food Intake

One common effect of THC is increased food intake [20][22], which is mediated by CB1 and induced by stimulation of dopamine release in the nucleus accumbens [6].

CBD has a low affinity for the CB1 receptor, and concentrations of 3 to 100 mg/kg body weight (bw) administered intraperitoneally (i.p.) resulted in no significant effects on food intake in mice [23][25] or rats. However, CBD (20mg/kg bw i.p.) decreased hyperphagia induced by CB1 and 5-HT1A receptor agonists in rats [26].

Conversely, chronic use of CBD for up to 14 days reduced body weight gain in rats at doses of 2.5 and 5 mg/kg bw. This effect was prevented by co-administration of a CB2 receptor antagonist [27].

Cataleptic Effects and Motor Changes

Typical antipsychotic drugs exhibit catalepsy as a side effect, which is mediated by the blockade of dopamine receptors in the dorsal striatum. These drugs may counteract the stereotypical actions of dopaminergic agents in rodents, including d-amphetamine, and hyperlocomotion induced by dopaminergic agents or antagonism of the N-methyl-d-aspartate (NMDA) glutamate-receptor subtype. Moreover, these dopaminergic agents cause decreased social interaction and disruption of the prepulse inhibition of the startle reflex. The antagonism of these effects is predictive for compounds with antipsychotic activity [28].

Several studies have evaluated the antipsychotic-like properties of CBD in animal models. This cannabinoid has not been shown to induce catalepsy, even at doses as high as 480 mg/kg bw [12][29][32].

Motor changes were investigated in studies of possible anxiolytic and antidepressant effects of CBD. Antidepressant drugs activate the 5-HT1A receptors [33], and CBD may also exhibit agonist properties at 5-HT1A receptors [34]. CBD shows anxiolytic-like and antidepressant-like effects with an inverted U-shaped profile, but does not induce motor changes [23][28][35][36].

Effects on Physiological Parameters in Animals

Several studies administering CBD by different routes have shown it to be safe, in regards to the effects on physiological parameters.

At a wide range of doses (3-30mg/kg bw i.p.), CBD does not affect blood pressure, heart rate, body temperature, glucose levels, pH, Pco2, Po2, hematocrit, K

+ or Na

+ levels,

gastrointestinal transit or rectal temperature in rodents [24][37][42]. The results were the same, even after 14 days of treatment [43]. An in vitro study showed that the cannabinoid failed to induce contraction in mouse small intestine at concentrations ranging from 0.01�mol/L to 10.0�mol/L [37]. Furthermore, CBD has not shown significant effects on open-field physiological activity (defecation and urination) nor on vocalization behavior [39]. Mice treated with 60 mg/kg bw CBD i.p. three times per

Safety, Side Effects of Cannabidiol Current Drug Safety, 2011, Vol. 6, No. 4 3

week for 12 weeks did not experience significant side effects such as ataxia, kyphosis,

generalized tremor, swaying gait, or

tail stiffness [44]. Finally, CBD at 10 and 20mg/kg bw i.p. did not produce emesis in mice [45].

Another study performed to determine whether CBD is an agonist at rat TRPV1 receptors in vivo demonstrated the safety of this cannabinoid in other physiological parameters. Rats received a CBD injection (0.003-6.36�mol; 1-2,000�g intra-arterially), but did not exhibit appreciable effects on mean blood pressure, arterial blood gas tensions, pH, ventilatory responses or respiratory minute volume. This study provided evidence that CBD does not affect ventilation [46].

Cannabinoids interact at different degrees with TRP channels, being CBD most potent at TRPV1 [47]. Stimulation of vanilloid receptors induces vasodilation and inflammation. CBD has been shown to be a full agonist of human TRPV1 at concentrations lower than those needed to bind to CB1/CB2 receptors, usually at doses ranging from 10 to 50 mg/kg in humans, followed by a quick desensitization of TRPV1 receptors, which leads to the depletion of sensory nociceptors [48].

CBD (0.1-30mg/kg bw intravenously (i.v.)) had no effect on the rate of intestinal transit or the rate of gastric emptying, or cardiovascular, antinociception, hypothermia or respiratory parameters [29][49][50]. An evaluation of the neuroprotective activity of CBD revealed that CBD was not only free from significant side effects, but also associated with cardiac, hemodynamic, and ventilatory benefits in piglets [51].

It is important to note that the lack of CBD side effects was observed during studies whose primary objectives were not to evaluate CBD´s safety, but to study cannabinoid activity. Furthermore, several other studies that evaluated the anxiolytic effects of CBD in rodents demonstrated the safety and tolerability of this drug in rodents [52-57].

Effects on Monoamine Oxidase Activity

CBD (0.3-300�g/mg protein) was ineffective at inhibiting porcine monoamine oxidase activity of brain and liver mitochondria after 1 hr of incubation with mitochondrial preparation [58].

Effects on Memory

Short-term memory and other cognitive deficits have been reported in humans after smoking marijuana. In rats tested against a delayed match to sample task, THC showed a correlation between delay and dose-dependent behavioral deficit produced in this task. This performance was selectively impaired by a lack of discharge of hippocampal neurons. However, CBD at doses of 0.75-2.0mg/kg bw (i.p.) were tested in the same task and no significant effect on performance was observed [59].

Effects at Estrogen Receptors

Compounds possessing the tricyclic cannabinoid structure, including CBD, have been reported to interact with rodent estrogen receptors. To test the hypothesis that cannabinoids produce a direct activation of estrogen receptors, Ruh et al. [60] investigated whether cannabinoid

compounds exhibit estrogen-induced mitogenesis in MCF-7 breast cancer cells. CBD (1 and 10μM) did not significantly stimulate the proliferative response or transcriptional activity compared to controls. As a result, CBD failed to behave as an estrogen receptor agonist in vitro.

Studies in Humans

In human studies, CBD administration did not induce side effects across a wide range of dosages, including acute and chronic dose regimens, and tolerance to CBD did not develop.

Acute Studies

In the 1970s, human studies showed that oral CBD intake from 15 to 160mg [61-63], inhalation of 0.15mg/kg bw [64] or intravenous injection from 5 to 30mg [4][61] were not followed by ill effects.

CBD does not interfere with several psychomotor and psychological functions in humans. CBD does not affect heart rate, blood pressure, or performance in the verbal paired-associate learning test as measured by recall score at doses up to 600mg [5][62][65][74].

Subsequent studies concerning the antipsychotic effects of CBD have not reported any side effects after CBD intake [75-77].

Chronic Studies

Chronic oral administration of 10mg CBD daily for 21 days did not induce any changes in neurological (including electroencephalogram (EEG)), clinical (including electrocardiogram (EKG)), psychiatric, blood or urine examinations [78]. Likewise, oral CBD administration in healthy participants (3mg/kg bw daily for 30 days) and in epileptic patients (200-300mg daily for 135 days) was well tolerated and no signs of toxicity or serious side effects were detected on neurological and physical examinations, blood and urine analysis, or EKG and EEG, which were performed at weekly intervals [10].

CBD was evaluated for symptomatic efficacy and safety in 15 neuroleptic-free patients with Huntington's Disease. Effects after oral CBD (10mg/kg bw /day for 6 weeks) or placebo (sesame oil for 6 weeks) intake were evaluated weekly under a double-blind, randomized crossover design. CBD showed no significant or clinical differences compared to placebo in the Cannabis side effect inventory, clinical lab tests or other safety outcome variables. Also, weekly plasma levels of CBD (mean range 5.9 to 11.2 ng/ml), assayed by GC/MS, did not differ significantly over the 6 weeks of CBD administration [79].

A previous case report of a teenager diagnosed with schizophrenia who experienced severe side effects after treatment with conventional antipsychotics demonstrated significant improvement of symptoms with no adverse effects after hospitalization and 4 weeks of treatment with increasing doses of CBD up to 1,500mg/day [80]. More recently, CBD monotherapy was administered to three patients with treatment-resistant schizophrenia (initial oral dose of 40 mg, increased to 1,280mg/day) for up to 4 weeks with no side effects reported, even at the highest dose [81]. A similar result was observed in two patients with bipolar affective disorder who received CBD (600-1,200mg/day) for


up to 24 days [82]. A double-blind study with 42 patients diagnosed with schizophrenia or schizophreniform disorder (DSM-IV) in an acute episode showed that CBD (800mg) significantly reduced psychotic symptoms after 2 to 4 weeks of treatment and induced fewer side effects, such as extrapyramidal symptoms, increased prolactin levels, and weight gain, compared to amilsupride [83].

The efficacy and safety of CBD on Parkinson’s disease patients with psychotic symptoms were study in a 4-week open trial. A flexible oral dose of CBD, ranging from 150mg/day to 400mg/day in the last week, plus patients’ usual treatments showed that psychotic symptoms were significantly reduced; cognitive and motor symptoms were not affected by the cannabinoid and no serious side effects were reported [84]. A double-blind placebo controlled trial is currently underway by our group to evaluate the efficacy, safety, and tolerability of CBD in patients with Parkinson’s disease and psychosis.

Finally, a 19-year old female with a history of cannabis addiction received CBD 300mg on day 1, 600mg/day divided into two doses days 2 through 10, and CBD 300mg on day 11. During treatment with CBD, the patient did not report any marijuana withdrawal symptoms, and she did not experience anxiety or dissociative symptoms [67] or improved sleep quality, as assessed by standardized rating scales.

We did not include in this review studies on cannabis extracts or CBD-rich extracts, as the other several compounds may have multiple interactions with CBD. However, some clinical trials in multiple sclerosis have shown that the 1:1 mix of THC and CBD, which is available as an oromucosal spray (Sativex®) at doses ranging from 2.5 to 120 mg of each cannabinoid, showed no adverse effects on cognition or mood [85] or other than those observed with psychoactive drugs for pain treatment [86].

These studies concerning the safety of CBD administration are summarized in Tables 1 and 2.

Side Effects of CBD

Effect of Cannabidiol in the Human Immune System

The majority of available literature shows inhibitory capacities of cannabinoids, including CBD, on cells of the human immune system. CBD (2.5-10�g/ml) strongly inhibited interleukin (IL)-10 production in a virus-negative T-cell line, and increased IL-8, macrophage inflammatory protein 1� (MIP-1�) and MIP-1� production in an eosinophilic leukemia cell line and inhibited IL-8 production by B-cells. Since CBD decreased production of IL-8 and CC chemokines (MIP-1� and MIP-1�) by B-cells, a patient’s risk of infection with human immunodeficiency virus – 1 (HIV-1) or other infectious organisms may increase, along with a risk of disease progression. Previous reports suggested that IL-10 inhibits HIV-1 expression by infected macrophages [87-89]. Therefore, the strong inhibition of IL-10 production by CBD could be another mechanism by which this cannabinoid can up regulate HIV-1 production [90].

In summary, although these effects are of potential benefit in some conditions, they may worsen disease progression, HIV infection, tumor genesis, and metastases, and exacerbate allergic inflammation in the lung [90]. However, some results suggested that CBD could yield a biphasic response in the immune system with stimulatory capacity at lower doses (nanomolar concentrations) and inhibitory activity at higher doses (micromolar concentrations). Accordingly, an enhancement of mitogen-induced indoleamine 2,3-dioxygenase activity and secretion of interferon (IFN)-� by CBD (10-100ng/ml) and suppression of these activities at higher doses (1-10μg/ml) were observed in human peripheral blood mononuclear cells [91].

In in vivo evaluations of CBD in humans, significant correlations were found between IFN-� blood levels, neopterin, and the kynurenine-to-tryptophan ratio in various diseases, including human immunodeficiency virus

Table 1. Effects of CBD Administration in In Vitro Studies

Study Reference Cell Lines Dose Relevant Information

Ligresti et al. (2006) [16] tumoral cell lines 1-25μM no significant effect on non-transformed cells

Massi et al. (2006) [17] U87 human glioma cells 0-50�M no significant effect on non-transformed cells

Massi et al. (2008) [18] U87 human glioma cells 10-16�mol/L no significant effect on non-transformed cells

Paria et al. (1995) [19] mouse's embryo 6.4 -160nM no significant effect on embryonic development

de Filippis et al. (2008)

[37] mouse's small intestine muscle strips 0.01-10�mol/L no significant effects on inducing contraction

Schurr et al. (1976) [58] porcine's brain and liver mitochondria 0.3-300�g/mg protein no inhibition on porcine monoamine oxidase

activity

Ruh et al. (1997) [60] MCF-7 breast cancer cells 1–10�M no significant effect on estrogen receptors

Gallily et al. (2003) [101] human PBMC 1-15�g/ml no significant effect on non-transformed cells

Steger et al. (1990) [127] rat's pituitaries 0.1-10mg/kg bw no significant effect on luteinizing hormone

secretion

Abbreviations: bw, body weight; PBMC, peripheral blood mononuclear cells.


Table 2. Effects of CBD Administration in In Vivo Studies

Study Reference Species Route Dose Relevant Information

Zuardi et al. (1982) [5] human oral 1mg/kg bw no significant effects on heart rate and bodily

symptoms

Cunha et al. (1980) [10] human oral 3mg/kg bw; 200 and 300mg/day

no significant effects on neurological and physical examinations, blood and urine

analysis, electrocardiogram and

electroencephalogram

Ligresti et al. (2006)

[16] mouse intratumor 5mg/kg bw lower potency in noncancer cells

Massi et al. (2008) [18] mouse peritumoral 0.5 mg/mouse no significant effect on non-transformed cells

Riedel et al. (2009) [23] mouse intraperitoneal 10mg/kg bw no significant effects on weight gain and on

locomotor activity

El-Remessy et al. (2006)

[24] mouse intraperitoneal 10mg/kg bw no significant effect on weight gain and on

blood glucose levels

Wiley et al. (2005) [25] mouse intraperitoneal 0-100mg/kg bw no significant effect on weight gain

Scopinho et al. (2011)

[26] rat intraperitoneal 20mg/kg bw decreased induced-hyperphagia

Varvel et al. (2006) [29] mouse intravenous 1–30mg/kg bw no significant effects on catalepsy, antinociception and hypothermia

Zuardi et al. (1991) [30] rat intraperitoneal 15-480mg/kg bw no significant effect on catalepsy

Fairbairn et al. (1979)

[31] mouse oral 3.13-100mg/kg bw no significant effects on catalepsy

Pertwee et al. (1972)

[32] mouse intraperitoneal 5-100mg/kg bw no significant effect on catalepsy

Zanelati et al. (2010)

[35] mouse intraperitoneal 3-100mg/kg bw did not induce motor changes

Guimarães et al. (1990)

[36] rat intraperitoneal 2.5-20mg/kg bw did not induce motor changes

de Filippis et al. (2008)

[37] mouse intraperitoneal 10mg/kg bw no significant effects on gastrointestinal

motility

Hayakawa et al. (2007)

[38] mouse intraperitoneal 3mg/kg bw no significant effects on blood pH, Pco2, Po2, hematocrit, K+ and Na+ levels, glucose, blood

pressure, heart rate and rectal temperature

Hiltunen et al. (1988)

[39] rat intraperitoneal 10and 30mg/kg bw no significant effects on rectal temperature,

open-field physiological activity and on vocalization behavior

Hampson et al. (2000)

[40] rat intraperitoneal 20mg/kg bw no significant effects on Pco2, Po2, glucose,

blood pressure and rectal temperature

Resstel et al. (2006) [41] rat intraperitoneal 10mg/kg bw no significant effects on blood pressure and

heart rate

Chesher et al. (1973)

[42] mouse oral 6-30mg/kg bw no significant effects on gastrointestinal

motility

Hayakawa et al. (2007)

[43] mouse intraperitoneal 3mg/kg bw no significant effects on blood pH, Pco2, Po2,

hematocrit, K+ and Na+ levels and rectal

temperature

Dirikoc et al. (2007)

[44] mouse intraperitoneal 60mg/kg bw no significant effects on ataxia, kyphosis,

generalized tremor, swaying gait, tail stiffness

Darmani (2002) [45] shrew intraperitoneal 10 and 20mg/kg bw did not induce motor changes

McQueen et al. (2004)

[46] rat intra-arterial 0.003-6.36�mol; 1-

2,000�g

no significant effects on blood pressure, arterial blood gas tensions, pH, ventilatory responses

and respiratory minute volume

Shook et al. (1989) [49] mouse intravenous 0.1 - 100mg/kg bw no significant effects on the rate of intestinal

transit and of gastric emptying


(Table 2) contd…..


Graham et al. (1973)

[50] rat intravenous 1mg/kg bw no significant effect on cardiovascular and

respiratory parameters

Alvarez et al. (2008)

[51] piglet intravenous 0.1mg/kg bw no significant effects on blood pH, Pco2, Po2, heart rate, blood pressure, hemodynamic and

respiratory parameters

Heyser et al. (1993) [59] rat intraperitoneal 0.75-2.0mg/kg bw no effect delayed match to sample task

performance

Hollister (1973) [61] human oral 20-100mg no significant side effect

Hollister (1973) [61] human intravenous 5-30mg no significant side effect

Karniol et al. (1974)

[62] human oral 15-60mg no significant effects on heart rate, psychological

reactions and on time prduction tasks

Bergamaschi et al. (2011)

[65] human oral 600mg no significant effects on heart rate, blood

pressure, skin conductance, bodily symptoms

and psychological measurements

Crippa et al. (2011) [66] human oral 400mg no significant effects on subjective and

psychological measurements

Crippa et al. (2010) [67] human oral 300-600mg/day no significant side effect

Fusar-Poli et al. (2009)

[68] human oral 600mg no significant effects on heart rate, blood

pressure, task performance and psychological

measurements

Fusar-Poli et al. (2009)

[69] human oral 600mg no significant side effect

Bhattacharyya et al. (2009)

[70] human oral 600mg no significant effects on verbal learning task

and psychotic symptoms

Borgwardt et al. (2008)

[71] human oral 600mg no significant effects on intoxication, sedation, psychotic symptoms and motor inhibition task

Crippa et al. (2004) [72] human oral 400mg no significant effects psychological

measurements

Zuardi et al. (1993) [73] human oral 300mg no significant effects on heart rate, blood

pressure, psychomotor performance, bodily symptoms and psychological measurements

Consroe et al. (1979)

[74] human oral 200mg no significant impairments of motor and mental

performances

Hallak et al. (2011) [75] human oral 600mg no significant effects on heart rate, blood

pressure and behavior measurements

Bhattacharyya et al. (2010)

[76] human oral 600mg no significant effects on heart rate and

psychotic symptoms

Hallak et al. (2010) [77] human oral 300 and 600mg no significant side effect

Mincis et al. (1973) [78] human oral 10mg no significant change in neurological, clinical,

psychiatric, blood and urine examinations

Consroe et al. (1991)

[79] human oral 10mg/kg/day no significant side effect

Zuardi et al. (1995) [80] human oral 1,500mg/day no significant side effect

Zuardi et al. (2006) [81] human oral 40-1,280mg/day no significant side effect

Zuardi et al. (2010) [82] human oral 600-1,200mg/day no significant side effect

Leweke et al. (2007)

[83] human oral 800mg/day less side effect than amisulpride

Zuardi et al. (2009) [84] human oral 150-400mg/day no significant side effect

Steger et al. (1990) [127] rat oral 0.1-10mg/kg bw no significant effect on gonadal hormone levels

Abbreviations: bw, body weight; Pco2, carbon dioxide partial pressure;Po2, oxygen partial pressure; K+, potassium; Na+, sodium.


infection, malignancy and autoimmune syndromes [92-94]. Moreover, there are significant correlations between the decrease of tryptophan levels and the increased susceptibility of patients to mood disturbances and depression [95-97]. Activation of indoleamine 2,3-dioxygenase could represent a link between the immunological network and the pathogenesis of depression, when the availability of tryptophan limits serotonin biosynthesis [91, 96, 98].

Effects on Cell Viability

Studies of CBD evaluating cell viability and apoptosis have been conducted for decades [99]. The induction of apoptosis by the cannabinoids has been demonstrated primarily in leukemia, breast carcinoma, and glioma cells [100], but little information pertaining to primary cells is available. Some reports have shown a differential sensitivity between transformed and nontransformed monocytes and glia cells to CBD-induced apoptosis [16, 17, [101], implicating the potential use of CBD as an anticancer agent against sensitive tumors [102].

However, exposure of thymocytes to CBD (4–16μM) for 2h increased the mean fluorescence of 2',7'-dichlorofluorescin (DCF) in a concentration-related manner, indicating an elevated cellular ROS production. Nonetheless, CBD treatment significantly increased the DCF fluorescence in thymocytes and EL-4 thymoma cells. Time-course analyses revealed that CBD-mediated apoptosis occurred earlier in EL-4 cells than in thymocytes [102]. Several studies have reported a crucial role for ROS in CBD-induced apoptosis in glioma and leukemia cells [17][100].

Primary monocytes and glia cells are reportedly non-sensitive to CBD-induced apoptosis [17][101], but an enhancement of apoptosis by CBD treatment was observed in normal lymphocytes. CBD also increased splenocyte apoptosis via ROS-dependent activation of caspase-8 [102]. Exposure of splenocytes to CBD (4–8μM) elicited an early production of ROS with peak response at 1h post-CBD treatment and a parallel gradual decrease in cellular glutathione. In addition, CBD treatment (8μM) significantly stimulated caspase-8 activation. Although it did not demonstrate a positive impact on ROS production, pretreatment of splenocytes with a cell-permeable inhibitor for caspase-8 significantly attenuated CBD-mediated apoptosis in a concentration-dependent manner [103].

This pro-apoptotic property induced by CBD in normal lymphocytes could contribute to the immunosuppressive effects induced by this cannabinoid. The repercussions of this effect in patients with infectious diseases need to be investigated.

Inhibition of Hepatic Drug Metabolism

Cannabidiol is a potent inhibitor of hepatic drug metabolism and this effect raises the question of whether CBD can inhibit the metabolism of other drugs in vivo, affecting their metabolite concentration in the central nervous system [104][105].

The CBD-mediated inhibition of drug metabolism is likely a result of the covalent binding of a reactive CBD metabolite to hepatic microsomal P450 [106], which affect specific isozymes. Acute treatment with CBD in male rats

decreased hepatic cytochrome P450 content [107]. A similar effect was observed in mice, showing inactivation of specific cytochrome P450 isoforms belonging to the 2C and 3A subfamilies [108][109]. Orthologs of these P450s are also found in human liver microsomes, and immune inhibition studies show that their metabolite profiles are qualitatively similar to those of their mouse counterparts [110]. Furthermore, CBD can inactivate human P450 3A4 [111], which is responsible for metabolizing more than 60% of clinically prescribed drugs [112].

The metabolism of the main active constituent of Cannabis, THC, and the endogenous cannabinoid anandamide are inhibited by CBD. To determine the effect of CBD in P450-catalyzed anandamide metabolism, mice were treated with CBD (120mg/kg bw) before hepatic microsomes were prepared and incubated with anandamide. CBD treatment significantly inhibited the formation of two anandamide metabolites. Thus, mouse hepatic P450s 2C and 3A, which are selectively inactivated by CBD [113], may be involved in the formation of some, but not all, anandamide metabolites [114].

Vitamin A and the cannabinoids are metabolized by P450s 2C, and CBD-mediated inhibition of this enzyme may alter vitamin A metabolism. This interaction may be clinically important, especially when large doses of vitamin A are therapeutically employed in xerophthalmia treatment [108].

Compounds that inhibit or inactivate cytochrome P450s after acute treatment can also induce P450s after long-term exposure. For example, CBD can inactivate cytochrome P450s after acute administration and can also induce P450s after repeated use in mice. In fact, Bornheim and Correia [115] showed that acute CBD treatment decreased the mouse hepatic cytochrome P450 content, while multiple CBD treatment regimens induced cytochrome P450s, which was indistinguishable from induction by phenobarbital, suggesting the involvement of the 2B subfamily [116]. Mice treated with CBD showed initial inactivation of P450s 3A and 2C, with a subsequent increase in mRNA encoding P450s 3A, 2C, and 2BlO after repeated administration [117].

In summary, the metabolism of drugs by cytochrome P450s 3A, 2C and 2B subfamilies can be affected when CBD in simultaneously administered. On the other hand, CBD extracts or Sativex� do not seem to inhibit or induce hepatic CYP450, probably because the administration of CBD and THC is simultaneous, which avoids the pharmacokinetic interaction, in addition to the fact that the dose ratios are very low (=1) to induce pharmacokinetic blockade [118][119].

Effects on P-Glycoprotein Activity and Other Drug

Transporters

P-glycoprotein (P-gp) is a protein that plays an important role in the disposition of many endogenous and exogenous compounds. P-gp is an ATP-dependent efflux transporter coded by the multidrug resistance 1 (MDR1) gene. Usually, P-gp activity is measured in the distal region of the small intestine where basal expression levels of this protein are higher than in other regions of the body. Human polymorphisms in the MDR1 gene can alter P-gp expression


and function, yielding altered drug pharmacokinetics and pharmacodynamics. MDR1 polymorphisms are one of the primary mechanisms responsible for the low oral bioavailability and limited brain penetration of many therapeutic drugs [120].

An in vitro P-gp activity assay was performed using different CBD concentrations (0.1, 1, 25, 50 and 100μM). Depending on the P-gp substrates, CBD (3-100μM) exhibited potent inhibitory effects on P-gp efflux and on P-gp ATPase activity, leading to an increased intracellular accumulation of these substrates [116][120]. One hour of CBD exposure did not inhibit P-gp activity in drug-selected human MDR leukemia cells that over-expressed P-gp, but 3 days of repeat exposure to CBD decreased P-gp expression in these cell lines [121].

Cannabis and cannabinoids could interact with a range of cancer drugs, due to the overlapping substrate specificities of the multidrug transporters. Multidrug resistance-related protein 1 (ABCC1/MRPP1) is a membrane-bound, energy-dependent efflux transporter, which transports several drugs used clinically for cancer treatment. Additionally, breast cancer resistance protein (ABCG2/BCRP) is a transport protein found in cancer cell lines. CBD increased the intracellular accumulation of these substrates in vitro [122][123].

These findings are important since cannabinoid preparations are used to attenuate nausea and vomiting induced by cancer chemotherapy and are likely to be co-administered with anticancer drugs. Although inhibition of these transporters may be considered a side effect, this CBD-transporter interaction may lead to an increased bioavailability of cancer treatment drugs. However, it is important to remember that some pharmacokinetic and pharmacodynamic interactions may occur with these anticancer drugs, leading to undesirable effects, such as overdosing and toxicity.

Effects on Sex Steroids and Reproduction

CBD can inhibit fertilization in sea urchin Strongylocentrotus purpuratus by decreasing sperm fertilizing capacity and by inhibiting acrosome reaction in a concentration- and time-dependent manner. The receptivity of eggs to sperm is likely not affected [124][125].

Suppression of follicular steroidogenesis (production of testosterone, progesterone and estradiol-17�) has been demonstrated in vitro at a wide range of CBD concentrations (100-200μM). Luteinizing hormone-stimulated accumulation of progesterone and testosterone decreased, while estradiol accumulation was only slightly affected. A probable mechanism is that cannabinoids modulate the release of cholesterol from its ester storage in lipid droplets and, thus, limit the availability of the substrate for steroidogenesis [126]. Contradicting these results, no significant effect of CBD (0.1, 1 and 10 mg/kg bw) treatment was observed on luteinizing hormone levels, plasma follicle-stimulating hormone levels or testosterone levels in rats. None of the treatments altered rat luteinizing releasing hormone content. Moreover, CBD administration did not change luteinizing hormone secretion after in vitro luteinizing releasing hormone stimulation [127].

The enzyme progesterone 17�-hydroxylase generates precursors for the synthesis of glucocorticoids and sex steroids. It was inhibited by a high concentration of CBD (1mM), but was not significantly affected at lower concentrations (100�M), which can lead to time- and concentration- dependent inactivation. CBD treatment (10 and 120mg/kg bw) in rats showed inhibition of hepatic testosterone hydroxylase [107][108][128].

Toxicology

High Doses of Cannabidiol in Monkeys

The acute (i.v.) and subchronic (oral) effects of CBD at high doses were studied in rhesus monkeys [129]. CBD was injected at doses of 150, 200, 225, 250, or 300mg/kg bw i.v. Tremors were evident at all doses and the central nervous system inhibition progressed from sedation to prostration within 30min. Convulsions and emesis occurred at intermediate doses. Hyperpnoea was observed at the lowest dose and hypopnoea at higher doses. Changes in rectal temperatures were of borderline significance, but declined rapidly at higher doses. A dose- and time-related bradycardia occurred, which terminated in cardiac failure at the higher doses. Respiratory arrest and cardiac failure accounted for the death of the monkeys at doses above 200mg/kg bw. After smaller doses, survivors recovered in one to three days and liver weights increased from 19 to 142%; no changes in liver weight were observed at 300mg/kg bw, a dose that caused rapid death. There was a marked 57% decrease in relative testicular weight at 200mg/kg bw and a 33% increase in ovarian weight at this same dose.

In a study of the effects of subchronic CBD, four monkeys/sex/dose received oral treatment with CBD at doses of 30, 100, or 300mg/kg bw daily for 90 days. Clinical measures, growth rates, rectal temperatures and EKG recordings were within normal limits. Significant changes were observed in organ relative weights (ratio to brain weight). Liver weights of both sexes increased 13 to 56% and kidney weights increased 16 to 22%. These increases were not strictly related to the dose administered. Heart weights increased 16 to 22% at the highest dose. A dose-related decrease in testicular size was observed after 90 days. After a 30-day recovery interval, testicular size remained diminished. Inhibition of spermatogenesis occurred in all monkeys that received the highest dose of CBD.

A brief summary of these reported side effects are described in Tables 3 and 4.

CONCLUSION

Several studies suggest that CBD is well tolerated and safe in humans at high doses and with chronic use. However, in vitro and in vivo studies showed potential drug metabolism interactions, cytotoxicity, and decreased receptor activity. This data highlights the need for careful monitoring of CBD use in humans, especially when CBD is used in clinical practice, such as in the treatment of psychiatric disorders or as an option for drug abuse treatment [130].

Nonetheless, some pharmacokinetic data regarding CBD should be highlighted. High inter-individual variability was


noted by the smoked route, with an average of 31% (11- 45%). CBD has a half-life of 24 hours on average, with a twofold in the time noted by i.v. route and average of 31 hours by smoke route. CBD is cleared from a plasma at rates between 960 and 1560 ml/min and its distribution volume is estimated to be around 30L/kg [131].

Since several studies on CBD involve animals, the different metabolic profiles between species must be taken into account. CBD metabolism seems to follow the same pathways across species, although variations may occur, such as the involvement of different enzymes leading to diverse positions of hydroxylated compounds, or still the enrollment of a different type of sugar (or more than one) during conjugation, which could explain some slight differences in CBD effects or in metabolites between species [132].

Owing to advances in legislation concerning Cannabis use and newly available phytocannabinoid-based drugs for the treatment of chronic diseases, including multiple sclerosis, the public and scientific interest in Cannabis research and administration in humans has increased. Thus, in vivo studies, as well as randomized, double-blind placebo-controlled clinical studies, are still needed to assess cannabinoid effects in biological systems.

CONFLICTS OF INTEREST

The authors declare that they have no conflicts of interest.

ACKNOWLEDGMENTS

M.M.B. received grants from FAPESP and CAPES. A.W.Z. and J.A.S.C are recipients of CNPq Productivity Awards.

Table 3. Effects of CBD Administration in In Vitro Studies

Study Reference Cell lines Dose Relevant Information

Srivastava et al. (1998)

[90] HUT-78 2.5-10�g/ml inhibited IL-10 production


[90] SRIS-EOSL 2.5-5�g/ml increased IL-8, MIP-1� and MIP-1� production


[90] SRIH-B (ATL) 2.5-10�g/ml decreased IL-8, MIP-1� and MIP-1� production

Jenny et al. (2009)

[91] human PBMC 10-100ng/ml increased mitogen-induced indoleamine 2,3-dioxygenase and

IFN-� activity

Jenny et al. (2009)

[91] human PBMC 1–10μg/ml decreased mitogen-induced indoleamine 2,3-dioxygenase and

IFN-� activity

Lee et al. (2008) [102] mouse thymocyte and EL-4

thymoma line 12–16μM induced apoptosis in non-transformed cells

Wu et al. (2008) [103] mouse splenocytes 4-8μM induced apoptosis in non-transformed cells

Paton et al. (1972) [105] mouse liver homogenate 12.7-

254.8�mol/L inhibition on hepatic drug metabolism

Zhu et al. (2006) [120] human P-gp membranes 5-100μM decreased P-gp ATPase activity

Holland et al. (2006)

[121] T lymphoblastoid leukaemia

cell line 1-10μM decreased P-gp expression


[122] human ovarian carcinoma cell

line 50-200μM decreased ABCC1 activity


[123] mouse embryonic fibroblasts 10-50μM decreased ABCG2 activity

Schuel et al. (1987)

[124] sea urchin sperms 0.1-10μM decreased fertilizing capacity

Schuel et al. (1991)

[125] sea urchin sperms 0.1-100μM inhibited acrosome reaction

Reich et al. (1982)

[126] rat Graafian follicle 100-200μM decreased steroid accumulation

Watanabe et al. (2005)

[128] rat testis microsomes 1mM decreased progesterone 17-hydroxylase activity

Watanabe et al. (2005)

[128] rat liver microsomes 100-1000μM decreased testosterone metabolism

Abbreviations: HUT-78, HTLV-1 genome positive, virus negative T cell line; SRIS-EOSL, eosinophilic leukemia cell line; SRIH-B (ATL), HTLV-1 positive B cell line; PBMC, peripheral blood mononuclear cells; IL-10, Interleukin-10; IL-8, Interleukin-8; MIP-1�, Macrophage inflammatory protein-1�; MIP-1�, Macrophage inflammatory protein-1�; IFN-

�, Interferon gamma; P-gp, P-glycoprotein; ABCC1, ATP-binding cassette transporter; ABCG2, ATP-binding cassette sub-family G member 2.


REFERENCES

[1] Grlie L. A comparative study on some chemical and biological characteristics of various samples of cannabis resin. Bull Narcot

1976; 14: 37–46. [2] Mehmedic Z, Chandra S, Slade D, et al. Potency trends of �9-THC

and other cannabinoids in confiscated cannabis preparations from 1993 to 2008. J Forensic Sci 2010; 55: 1209-17.

[3] Potter DJ, Clark P, Brown MB. Potency of delta 9-THC and other cannabinoids in cannabis in England in 2005: implications for

psychoactivity and pharmacology. J Forensic Sci 2008; 53: 90-4. [4] Perez-Reyes M, Timmons MC, Davis KH, Wall ME. A comparison

of the pharmacological activity in man of intravenously administered delta-9-tetrahydrocannabinol, cannabinol and

cannabidiol. Experientia 1973; 29: 1368-9. [5] Zuardi AW, Shirakawa I, Finkelfarb E, Karniol IG. Action of

cannabidiol on the anxiety and other effects produced by delta 9-THC in normal subjects. Psychopharmacology (Berl) 1982; 76:

245–50. [6] Pertwee RG. The diverse CB1 and CB2 receptor pharmacology of

three plant cannabinoids: delta9-tetrahydrocannabinol, cannabidiol and delta9-tetrahydrocannabivarin. Br J Pharmacol 2008; 153(2):

199-215. [7] Zuardi AW, Hallak JE, Crippa JA. Interaction between cannabidiol

(CBD) and �(9)-tetrahydrocannabinol (THC): influence of administration interval and dose ratio between the cannabinoids.

Psychopharmacology (Berl) 2011; IN PRESS. [8] Adams R, Hunt M, Clark JH. Structure of cannabidiol, a product

isolated from the marihuana extract of Minnesota wild hemp. J Am Chem Soc 1940; 62: 196-200.

[9] Mechoulam R, Shvo Y. The structure of cannabidiol. Tetrahedron 1963; 19: 2073-8.

[10] Cunha JM, Carlini EA, Pereira AE, et al. Chronic administration of cannabidiol to healthy volunteers and epileptic patients.

Pharmacology 1980; 21: 175-85. [11] Zuardi AW, Crippa JA, Hallak JE, Moreira FA, Guimarães FS.

Cannabidiol, a Cannabis sativa constituent, as an antipsychotic drug. Braz J Med Biol Res 2006; 39(4): 421-9.

[12] Zuardi AW. Cannabidiol: from an inactive cannabinoid to a drug with wide spectrum of action. Rev Bras Psiquiatr 2008; 30(3): 271-

80. [13] Izzo AA, Borrelli F, Capasso R, Di Marzo V, Mechoulam R. Non-

psychotropic plant cannabinoids: new therapeutic opportunities from an ancient herb. Trends Pharmacol Sci 2009; 30(10): 515-27.

[14] Carrier EJ, Auchampach JA, Hillard CJ. Inhibition of an equilibrative nucleoside transporter by cannabidiol: a mechanism

of cannabinoid immunosuppression. Proc Natl Acad Sci U S A 2006; 103(20): 7895-900.

[15] Castillo A, Tolón MR, Fernández-Ruiz J, et al. The neuroprotective effect of cannabidiol in an in vitro model of newborn hypoxic-

ischemic brain damage in mice is mediated by CB(2) and adenosine receptors. Neurobiol Dis 2010; 37(2): 434-40.

[16] Ligresti A, Moriello AS, Starowicz K, et al. Antitumor activity of plant cannabinoids with emphasis on the effect of cannabidiol on

human breast carcinoma. J Pharmacol Exp Ther 2006; 318(3): 1375-87.

[17] Massi P, Vaccani A, Bianchessi S, Costa B, Macchi P, Parolaro D. The non-psychoactive cannabidiol triggers caspase activation and

oxidative stress in human glioma cells. Cell Mol Life Sci 2006; 63(17): 2057-66.

[18] Massi P, Valenti M, Vaccani A, et al. 5-Lipoxygenase and anandamide hydrolase (FAAH) mediate the antitumor activity of

cannabidiol, a nonpsychoactive cannabinoid. J Neurochem 2008; 104: 1091–1100.

Table 4. Effects of CBD Administration in In Vivo Studies


Jones et al. (1972)

[104] mouse intraperitoneal 50mg/kg bw inhibition on hepatic drug metabolism

Paton et al. (1972)

[105] mouse intraperitoneal 12.5-50mg/kg bw inhibition on hepatic drug metabolism

Bornheim et al. (1994)

[106] mouse intraperitoneal 120mg/kg bw changed hepatic cytochrome P450 content

Narimatsu et al. (1990)

[107] rat intraperitoneal 10mg/kg bw changed hepatic cytochrome P450 content, decreased

testosterone metabolism





Jaeger et al. (1992)






Comelli et al. (2008)

[116] rat oral 10mg/kg bw changed hepatic cytochrome P450 content


[117] mouse intraperitoneal 120mg/kg bw changed hepatic cytochrome P450 genetic expression

Rosenkrantz et al. (1981)

[129] monkey Intravenous 150-300mg/kg bw tremors, hypopnoea, hyperpnoea, convulsion, emesis,

bradycardia, liver and testicular weights changes

Rosenkrantz et al. (1981)

[129] monkey oral 30-300mg/kg bw heart, kidney and liver weights changes, testicular

size reduced and Inhibition of spermatogenesis

Abbreviations: bw, body weight.


[19] Paria BC, Das SK, Dey SK. The preimplantation mouse embryo is

a target for cannabinoid ligand-receptor signaling. Proc Natl Acad Sci USA 1995; 92(21): 9460-4.

[20] Hart CL, Ward AS, Haney M, Comer SD, Foltin RW, Fischman MW. Comparison of smoked marijuana and oral D9-

tetrahydrocannabinol in humans. Psychopharmacology 2002; 164: 407–415.

[21] Williams CM, Rogers PJ, Kirkham TC. Hyperphagia in pre-fed rats following oral D9-THC. Physiol Behav 1998; 65: 343–6.

[22] Koch JE. Delta(9)-THC stimulates food intake in Lewis rats: effects on chow, high-fat and sweet high-fat diets. Pharmacol

Biochem Behav 2001; 68: 539–43. [23] Riedel G, Fadda P, McKillop-Smith S, Pertwee RG, Platt B,

Robinson L. Synthetic and plant-derived cannabinoid receptor antagonists show hypophagic properties in fasted and non-fasted

mice. Br J Pharmacol 2009; 156(7): 1154-66. [24] El-Remessy AB, Al-Shabrawey M, Khalifa Y, Tsai NT, Caldwell

RB, Liou GI. Neuroprotective and blood-retinal barrier-preserving effects of cannabidiol in experimental diabetes. Am J Pathol 2006;

168(1): 235-44. [25] Wiley JL, Burston JJ, Leggett DC, et al. CB1 cannabinoid receptor-

mediated modulation of food intake in mice. Br J Pharmacol 2005; 145(3): 293-300.

[26] Scopinho AA, Guimarães FS, Corrêa FM, Resstel LB. Cannabidiol inhibits the hyperphagia induced by cannabinoid-1 or serotonin-1A

receptor agonists. Pharmacol Biochem Behav 2011; 98(2): 268-72. [27] Ignatowska-Jankowska B, Jankowski MM, Swiergiel AH.

Cannabidiol decreases body weight gain in rats: involvement of CB2 receptors. Neurosci Lett 2011; 490(1): 82-4

[28] Moreira FA, Guimarães FS. Cannabidiol inhibits the hyperlocomotion induced by psychotomimetic drugs in mice. Eur J

Pharmacol 2005; 512(2-3): 199-205. [29] Varvel SA, Wiley JL, Yang R, et al. Interactions between THC and

cannabidiol in mouse models of cannabinoid activity. Psychopharmacology (Berl) 2006; 186(2): 226-34.

[30] Zuardi AW, Rodrigues JA, Cunha JM. Effects of cannabidiol in animal models predictive of antipsychotic activity.

Psychopharmacology (Berl) 1991; 104(2): 260-4. [31] Fairbairn JW, Pickens JT. The oral activity of delta9-

tetrahydrocannabinol and its dependence on prostaglandin E2. Br J Pharmacol 1979; 67(3): 379-85.

[32] Pertwee RG. The ring test - a quantitative method for assessing the 'cataleptic' effect of cannabis in mice. Br J Pharmac 1972; 46: 753-

763. [33] Savitz J, Lucki I, Drevets WC. 5-HT1A receptor function in major

depressive disorder. Prog Neurobiol 2009; 88: 17–31. [34] Russo EB, Burnett A, Hall B, Parker KK. Agonistic properties of

cannabidiol at 5-HT1a receptors. Neurochem Res 2005; 30: 1037–1043.

[35] Zanelati TV, Biojone C, Moreira FA, Guimarães FS, Joca SR. Antidepressant-like effects of cannabidiol in mice: possible

involvement of 5-HT1A receptors. Br J Pharmacol 2010; 159(1): 122-8.

[36] Guimarães FS, Chiaretti TM, Graeff FG, Zuardi AW Antianxiety effect of cannabidiol in the elevated plus-maze.

Psychopharmacology (Berl) 1990; 100: 558–9. [37] de Filippis D, Iuvone T, d'amico A, et al. Effect of cannabidiol on

sepsis-induced motility disturbances in mice: involvement of CB receptors and fatty acid amide hydrolase. Neurogastroenterol Motil

2008; 20(8): 919-27. [38] Hayakawa K, Mishima K, Nozako M, Hazekawa M, Irie K,

Fujioka M. Delayed treatment with cannabidiol has a cerebroprotective action via a cannabinoid receptor-independent

myeloperoxidase-inhibiting mechanism. J Neurochem 2007; 102(5): 1488-96.

[39] Hiltunen AJ, Järbe TU, Wängdahl K. Cannabinol and cannabidiol in combination: temperature, open-field activity, and vocalization.

Pharmacol Biochem Behav 1988; 30(3): 675-8. [40] Hampson AJ, Grimaldi M, Lolic M, Wink D, Rosenthal R, Axelrod

J. Neuroprotective antioxidants from marijuana. Ann N Y Acad Sci 2000; 899: 274-82.

[41] Resstel LB, Joca SR, Moreira FA, Corrêa FM, Guimarães FS. Effects of cannabidiol and diazepam on behavioral and

cardiovascular responses induced by contextual conditioned fear in rats. Behav Brain Res 2006; 172(2): 294-8.

[42] Chesher GB, Dahl CJ, Everingham M, Jackson DM, Marchant-

Williams H, Starmer GA. The effect of cannabinoids on intestinal motility and their antinociceptive effect in mice. Br J Pharmacol

1973; 49(4): 588-94. [43] Hayakawa K, Mishima K, Nozako M, et al. Repeated treatment

with cannabidiol but not D9-tetrahydrocannabinol has a neuroprotective effect without the development of tolerance.

Neuropharmacology 2007; 52: 1079-87. [44] Dirikoc S, Priola SA, Marella M, Zsürger N, Chabry J.

Nonpsychoactive cannabidiol prevents prion accumulation and protects neurons against prion toxicity. J Neurosci 2007; 27(36):

9537-44. [45] Darmani, N. A. The potent emetogenic effects of the

endocannabinoid, 2-AG (2-arachidonoylglycerol) are blocked by delta(9)-tetrahydrocannabinol and other cannnabinoids. J

Pharmacol Exp Ther 2002; 300(1): 34-42. [46] McQueen DS, Bond SM, Smith PJ, Balali-Mood K, Smart D.

Cannabidiol lacks the vanilloid VR1-mediated vasorespiratory effects of capsaicin and anandamide in anaesthetised rats. Eur J

Pharmacol 2004; 491(2-3): 181-9. [47] De Petrocellis L, Ligresti A, Moriello AS, et al. Effects of

cannabinoids and cannabinoid-enriched Cannabis extracts on TRP channels and endocannabinoid metabolic enzymes. Br J Pharmacol

2011; 163(7): 1479-94. [48] Bisogno T, Hanus L, De Petrocellis L, et al. Molecular targets for

cannabidiol and its synthetic analogues: effect on vanilloid VR1 receptors and on the cellular uptake and enzymatic hydrolysis of

anandamide. Br J Pharmacol 2001; 134(4): 845-52. [49] Shook JE, Burks TF. Psychoactive cannabinoids reduce

gastrointestinal propulsion and motility in rodents. J Pharmacol Exp Ther 1989; 249(2): 444-9.

[50] Graham JD, Li DM. Cardiovascular and respiratory effects of cannabis in cat and rat. Br J Pharmacol 1973; 49(1): 1-10.

[51] Alvarez FJ, Lafuente H, Rey-Santano MC, et al. Neuroprotective effects of the nonpsychoactive cannabinoid cannabidiol in hypoxic-

ischemic newborn piglets. Pediatr Res 2008; 64(6): 653-8. [52] Campos AC, Guimarães FS. Evidence for a potential role for

TRPV1 receptors in the dorsolateral periaqueductal gray in the attenuation of the anxiolytic effects of cannabinoids. Prog

Neuropsychopharmacol Biol Psychiatry 2009; 33(8): 1517-21. [53] Resstel LB, Tavares RF, Lisboa SF, Joca SR, Corrê a FM,

Guimarães FS. 5-HT1A receptors are involved in the cannabidiol-induced attenuation of behavioural and cardiovascular responses to

acute restraint stress in rats. Br J Pharmacol 2009; 156(1): 181-8. [54] Campos AC, Guimara �es FS. Involvement of 5HT1A receptors in

the anxiolytic- like effects of cannabidiol injected into the dorsolateral periaqueductal gray of rats. Psychopharmacology

(Berl) 2008; 199(2): 223-30. [55] Moreira FA, Campos AC, Guimarães FS. Involvement of 5HT1A

receptors in the anxiolytic-like effects of cannabidiol injected into the dorsolateral periaqueductal gray of rats. Psychopharmacology

(Berl) 2008; 199(2): 223-30. [56] Moreira FA, Aguiar DC, Guimarães FS. Anxiolytic-like effect of

cannabidiol in the rat Vogel conflict test. Prog Neuropsychopharmacol Biol Psychiatry 2006; 30(8): 1466-71.

[57] Zuardi AW, Karniol IG. Changes in the conditioned emotional response of rats induced by �9-THC, CBD and mixture of the two

cannabinoids. Arq Biol Tecnol 1983; 26: 391-7. [58] Schurr A, Livne A. Differential inhibition of mitochondrial

monoamine oxidase from brain by hashish components. Biochem Pharmacol 1976; 25(10): 1201-3.

[59] Heyser CJ, Hampson RE, Deadwyler SA. Effects of delta-9-tetrahydrocannabinol on delayed match to sample performance in

rats: alterations in short-term memory associated with changes in task specific firing of hippocampal cells. J Pharmacol Exp Ther

1993; 264(1): 294-307. [60] Ruh MF, Taylor JA, Howlett AC, Welshons WV. Failure of

cannabinoid compounds to stimulate estrogen receptors. Biochem Pharmacol 1997; 53(1): 35-41.

[61] Hollister, L.E. Cannabidiol and cannabinol in man. Experientia 1973; 29: 825-6.

[62] Karniol IG, Shirakawa I, Kasinski N, Pfeferman A, Carlini EA. Cannabidiol interferes with the effects of delta 9 -

tetrahydrocannabinol in man. Eur J Pharmacol 1974; 28(1): 172-7.


[63] Carlini EA, Masur J, Magalhães CCPB. Possível efeito hipnótico

do cannabidiol no ser humano. Estudo preliminar. Ciência e Cultura 1979; 31: 315-322.

[64] Dalton WS, Martz R, Lemberger L, Rodda BE, Forney RB. Influence of cannabidiol on delta-9-tetrahydrocannabinol effects.

Clin. Pharmacol. Ther 1976; 19: 300-9. [65] Bergamaschi MM, Queiroz RH, Chagas MH, et al. Cannabidiol

reduces the anxiety induced by simulated public speaking in treatment-naïve social phobia patients. Neuropsychopharmacology

2011; 36(6): 1219-26. [66] Crippa JA, Derenusson GN, Ferrari TB et al. Neural basis of

anxiolytic effects of cannabidiol (CBD) in generalized social anxiety disorder: a preliminary report. J Psychopharmacol 2011;

25(1): 121-30. [67] Crippa JA, Zuardi AW, Hallak JE. Therapeutical use of the

cannabinoids in psychiatry. Rev Bras Psiquiatr. 2010; 32 Suppl 1: S56-66.

[68] Fusar-Poli P, Crippa JA, Bhattacharyya S, et al. Distinct effects of (delta)9-tetrahydrocannabinol and cannabidiol on neural activation

during emotional processing. Arch Gen Psychiatry 2009; 66(1): 95-105.

[69] Fusar-Poli P, Allen P, Bhattacharyya S, et al. Modulation of effective connectivity during emotional processing by Delta9-

tetrahydrocannabinol and cannabidiol. Int J Neuropsychopharmacol 2009; 24: 1-12.

[70] Bhattacharyya S, Fusar-Poli P, Borgwardt S, et al. Modulation of mediotemporal and ventrostriatal function in humans by Delta9-

tetrahydrocannabinol: a neural basis for the effects of Cannabis sativa on learning and psychosis. Arch Gen Psychiatry 2009; 66(4):

442-51. [71] Borgwardt SJ, Allen P, Bhattacharyya S, et al. Neural basis of

Delta-9-tetrahydrocannabinol and cannabidiol: effects during response inhibition. Biol Psychiatry 2008; 64(11): 966-73.

[72] Crippa JA, Zuardi AW, Garrido GE, et al. Effects of cannabidiol (CBD) on regional cerebral blood flow. Neuropsychopharmacology

2004; 29(2): 417-26. [73] Zuardi AW, Cosme RA, Graeff FG, Guimarães FS. Effects of

ipsapirone and cannabidiol on human experimental anxiety. J Psychopharmacology 1993; 7: 82-8.

[74] Consroe PF, Carlini EA, Zwicker AP, Lacerda LA. Interaction of cannabidiol and alcohol in humans. Psychopharmacology 1979; 66:

45-50. [75] Hallak JE, Dursun SM, Bosi DC, et al. The interplay of

cannabinoid and NMDA glutamate receptor systems in humans: preliminary evidence of interactive effects of cannabidiol and

ketamine in healthy human subjects. Prog Neuropsychopharmacol Biol Psychiatry 2011; 35(1): 198-202.

[76] Bhattacharyya S, Morrison PD, Fusar-Poli P, et al. Opposite effects of delta-9-tetrahydrocannabinol and cannabidiol on human brain

function and psychopathology. Neuropsychopharmacology 2010; 35(3): 764-74.

[77] Hallak JE, Machado-de-Sousa JP, Crippa JA, et al. Performance of schizophrenic patients in the Stroop Color Word Test and

electrodermal responsiveness after acute administration of cannabidiol (CBD). Rev Bras Psiquiatr 2010; 32(1): 56-61.

[78] Mincis M, Pfeferman A, Guimarães RX, et al. Chronic administration of cannabidiol in man. Pilot study. AMB Rev Assoc

Med Bras 1973; 19(5): 185-90. [79] Consroe P, Laguna J, Allender J, et al. Controlled clinical trial of

cannabidiol in Huntington's disease. Pharmacol Biochem Behav 1991; 40(3): 701-8.

[80] Zuardi AW, Morais SL, Guimarães FS, Mechoulam R. Antipsychotic effect of cannabidiol. J Clin Psychiatry 1995;

56(10): 485-6. [81] Zuardi AW, Hallak JE, Dursun SM, et al. Cannabidiol

monotherapy for treatment-resistant schizophrenia. J Psychopharmacol. 2006; 20(5): 683-6.

[82] Zuardi AW, Crippa J, Dursun S, et al. Cannabidiol was ineffective for manic episode of bipolar affective disorder. J Psychopharmacol

2010; 24(1): 135-7. [83] Leweke FM, Koethe D, Gerth CW, et al. Cannabidiol as an

antipsychotic. A double-blind, controlled clinical trial on cannabidiol vs amisulpride in acute schizophrenia. Eur Psychiatry

2007; 22: S14.02.

[84] Zuardi AW, Crippa J, Hallak J, et al. Cannabidiol for the treatment

of psychosis in Parkinson’s disease. J Psychopharmacol 2009; 23(8): 979-983.

[85] Wade DT, Makela P, Robson P, House H, Bateman C. Do cannabis-based medicinal extracts have general or specific effects

on symptoms in multiple sclerosis? A double-blind, randomized, placebo-controlled study on 160 patients. Mult Scler 2004; 10(4):

434-41. [86] Notcutt W, Price M, Miller R, et al. Initial experiences with

medicinal extracts of cannabis for chronic pain: results from 34 'N of 1' studies. Anaesthesia. 2004; 59(5): 440-52.

[87] Poli G, Fauci AS. Cytokine modulation of HIV expression. Semin Immunol 1993; 5(3): 165-73.

[88] Moriuchi H, Moriuchi M, Combadiere C, Murphy PM, Fauci AS. CD8q T-cell derived soluble factor_s., but non B-chemokines

RANTES, MIP-1a and MIP-1b suppress HIV-1 replication in monocytesrmacrophages. Proc Natl Acad Sci 1996; 93: 15341–5.

[89] Cramer B, Verhoef J, Peterso, PK. Macrophages, cytokines, and HIV. J Lab Clin Med 1997; 129: 10–6.

[90] Srivastava MD, Srivastava BI, Brouhard B.. D9-Tetrahydrocannabinol and cannabidiol alter cytokine production by

human immune cells. Immunopharmacology 1998; 40(3): 179-85. [91] Jenny M, Santer E, Pirich E, Schennach H, Fuchs D. �9-

Tetrahydrocannabinol and cannabidiol modulate mitogen-induced tryptophan degradation and neopterin formation in peripheral blood

mononuclear cells in vitro. J Neuroimmunol 2009; 207(1-2): 75-82. [92] Murr C, Widner B, Wirleitner B, Fuchs D. Neopterin as a marker

for immune system activation. Curr Drug Metab 2002; 3: 175–87. [93] Wirleitner B, Neurauter G, Schroecksnadel K, Frick B, Fuchs D.

Interferon-�-induced conversion of tryptophan: immunologic and neuropsychiatric aspects. Curr Med Chem 2003; 10: 1581–91.

[94] Schroecksnadel K, Wirleitner B, Winkler C, Fuchs D. Monitoring tryptophan metabolism in chronic immune activation. Clin Chim

Acta 2006; 364: 82–90. [95] Huang A, Fuchs D, Widner B, Glover C, Henderson DC, Allen-

Mersh, TG. Serum tryptophan decrease correlates with immune activation and impaired quality of life in colorectal cancer. Br J

Cancer 2002; 86, 1691–6. [96] Widner B, Laich A, Sperner-Unterweger B, Ledochowski M, Fuchs

D. Neopterin production tryptophan degradation and mental depression: what is the link? Brain Behav Immun 2002; 16: 590–5.

[97] Capuron L, Neurauter G, Musselman DL, Lawson DH, Nemeroff CB, Fuchs D. Interferon-alpha-induced changes in tryptophan

metabolism. Relationship to depression and paroxetine treatment. Biol Psychiatry 2003; 54: 906–14.

[98] Russo S, Kema IP, Fokkema MR, et al. Tryptophan as a link between psychopathology and somatic states. Psychosom Med

2003; 65: 665–71. [99] Guzmán M. Effects on cell viability. Handb Exp Pharmacol. 2005;

(168): 627-42. [100] McKallip RJ, Jia W, Schlomer J, Warren JW, Nagarkatti PS,

Nagarkatti M. Cannabidiol-induced apoptosis in human leukemia cells: a novel role of cannabidiol in the regulation of p22phox and

Nox4 expression. Mol Pharmacol 2006; 70: 897–908. [101] Gallily R, Even-Chena T, Katzavian G, Lehmann D, Dagan A,

Mechoulam R. Gamma-irradiation enhances apoptosis induced by cannabidiol, a non-psychotropic cannabinoid, in cultured HL-60

myeloblastic leukemia cells. Leuk Lymphoma 2003; 44: 1767–73. [102] Lee CY, Wey SP, Liao MH, Hsu WL, Wu HY, Jan TR. A

comparative study on cannabidiol-induced apoptosis in murine thymocytes and EL-4 thymoma cells. Int Immunopharmacol 2008;

8(5): 732-40. [103] Wu HY, Chu RM, Wang CC, Lee CY, Lin SH, Jan TR.

Cannabidiol-induced apoptosis in primary lymphocytes is associated with oxidative stress-dependent activation of caspase-8.

Toxicol Appl Pharmacol 2008; 226(3): 260-70. [104] Jones G, Pertwee RG. A metabolic interaction in vivo between

cannabidiol and 1 –tetrahydrocannabinol. Br J Pharmacol 1972; 45(2): 375-7.

[105] Paton WDM, Pertwee RG. Effect of cannabis and certain of its constituents on pentobarbitone sleeping time and phenazone

metabolism. Br J Pharmac 1972; 44 : 250-61. [106] Bornheim LM, Everhart ET, Li J, Correia MA. Induction and

genetic regulation of mouse hepatic cytochrome P450 by cannabidiol. Biochem Pharmacol 1994; 48(1): 161-71.


[107] Narimatsu S, Watanabe K, Yamamoto I, Yoshimura H. Inhibition

of hepatic microsomal cytochrome P450 by cannabidiol in adult male rats. Chem Pharm Bull 1990; 38(5): 1365-8.

[108] Bornheim LM, Correia MA. Selective inactivation of mouse liver cytochrome P-4501IIA by cannabidiol. Mol Pharmacol 1990; 38:

319-26. [109] Bornheim LM, Correia MA. Purification and characterization of

the major hepatic cannabinoid hydroxyiase in the mouse: A possible member of the cytochrome P-450IIC subfamily. Mol

Pharmacol 1991; 40: 228-34. [110] Bornheim LM, Lasker JM, Raucy JL. Human hepatic microsomal

metabolism of �1-tetrahydrocannabinol. Drun Metab Dispos 1992; 2: 241-6.

[111] Jaeger W, Benet LZ, Bornheim LM. Inhibition of cyclosporine and tetrahydrocannabinol metabolism by cannabidiol in mouse and

human microsomes. Xenobiotica 1996; 26(3): 275-84. [112] Guengerich FP. In: Ortiz de Montellano PR, Ed. Cytochrome P450:

Structure, Mechanism, and Biochemistry. New York: Plenum Press. 1995; pp 473-535.

[113] Bornheim LM. In: Watson RR, Ed. Biochemistry and Physiology of Substance Abuse. Boca Raton: CRC Press. 1989; pp 21-35.

[114] Bornheim LM, Kim YK, Chen B, Correia MA. The Effect of Cannabidiol on Mouse Hepatic Microsomal Cytochrome P450-

Dependent Anandamide Metabolism. Biochem Biophys Res Commun 1993; 197(2): 740-6.

[115] Bornheim LM, Correia MA. Purification and characterization of a mouse liver cytochrome P450 induced by cannabidiol. Mol

Pharmacol 1989; 36: 377–83. [116] Comelli F, Giagnoni G, Bettoni I, Colleoni M, Costa B.

Antihyperalgesic effect of a Cannabis sativa extract in a rat model of neuropathic pain: mechanisms involved. Phytother Res 2008;

22(8): 1017-24. [117] Bornheim LM, Everhart ET, Li J, Correia MA. Induction and

genetic regulation of mouse hepatic cytochrome P450 by cannabidiol. Biochem Pharmacol 1994; 48(1): 161-71.

[118] Stott CG, Ayerakwa L, Wright S, et al. 2007. Lack of human cytochrome P450 induction by Sativex. 17th Annual Symposium

on the Canna- binoids. Saint-Sauveur, Quebec, Canada: International Cannabinoid Research Society. p 211.

[119] Stott CG, Guy GW, Wright S, et al. 2005b. The effects of cannabis extracts Tetranabinex and Nabidiolex on human cytochrome P450-

mediated metabolism. June 27 2005; Clearwater, FL. International Cannabinoid Research Association. p 163.

[120] Zhu HJ, Wang JS, Markowitz JS, et al. Characterization of P-

glycoprotein inhibition by major cannabinoids from marijuana. J Pharmacol Exp Ther 2006; 317(2): 850-7.

[121] Holland ML, Panetta JA, Hoskins JM et al. The effects of cannabinoids on P-glycoprotein transport and expression in

multidrug resistant cells. Biochem Pharmacol 2006; 71: 1146–54. [122] Holland ML, Allen JD, Arnold JC. Interaction of plant

cannabinoids with the multidrug transporter ABCC1 (MRP1). Eur J Pharmacol 2008; 591(1-3): 128-31.

[123] Holland ML, Lau DT, Allen JD, Arnold JC. The multidrug transporter ABCG2 (BCRP) is inhibited by plant-derived

cannabinoids. Br J Pharmacol. 2007; 152(5): 815-24. [124] Schuel H, Schuel R, Zimmerman AM, Zimmerman S.

Cannabinoids reduce fertility of sea urchin sperm. Biochem Cell Biol 1987; 65(2): 130-6.

[125] Schuel H, Berkery D, Schuel R, Chang MC, Zimmerman AM, Zimmerman S. Reduction of the fertilizing capacity of sea urchin

sperm by cannabinoids derived from marihuana. I. Inhibition of the acrosome reaction induced by egg jelly. Mol Reprod Dev 1991;

29(1): 51-9. [126] Reich R, Laufer N, Lewysohn O, Cordova T, Ayalon D, Tsafriri A.

In Vitro Effects of Cannabinoids on Follicular Function in the Rat. Biol Reprod. 1982; 27(1): 223-31.

[127] Steger RW, Murphy LL, Bartke A, Smith MS. Effects of psychoactive and nonpsychoactive cannabinoids on the

hypothalamic-pituitary axis of the adult male rat. Pharmacol Biochem Behav 1990; 37(2): 299-302.

[128] Watanabe K, Motoya E, Matsuzawa N, et al. Marijuana extracts possess the effects like the endocrine disrupting chemicals.

Toxicology 2005; 31; 206(3): 471-8. [129] Rosenkrantz H, Fleischman RW, Grant RJ. Toxicity of short-term

administration of cannabinoids to rhesus monkeys. Toxicol Appl Pharmacol. 1981; 58(1): 118-31.

[130] Russo EB. Taming THC: potential cannabis synergy and phytocannabinoid-terpenoid entourage effects. Br J Pharmacol

2011; 163(7): 1344-64. [131] Agurell S, Halldin M, Lindgren JE, et al. Pharmacokinetics and

metabolism of delta 1-tetrahydrocannabinol and other cannabinoids with emphasis on man. Pharmacol Rev 1986; 38(1): 21-43.

[132] Harvey DJ, Samara E, Mechoulam R. Comparative metabolism of cannabidiol in dog, rat and man. Pharmacol Biochem Behav. 1991;

40(3): 523-32.

Received: August 8, 2011 Revised: October 10, 2011 Accepted: October 10, 2011

Exhibit C

CNS Drugs. 2018 Oct 30. doi: 10.1007/s40263-018-0578-5. [Epub ahead of print]A Phase I, Randomized, Double-Blind, Placebo-Controlled, Single Ascending Dose, Multiple Dose, and Food Effect Trial of the Safety, Tolerability and Pharmacokinetics of Highly Purified Cannabidiol in Healthy Subjects.Taylor L1, Gidal B2, Blakey G3, Tayo B1, Morrison G4.Author informationAbstractBACKGROUND:A formal single ascending and multiple dose pharmacokinetic (PK) trial of cannabidiol (CBD) oral solution was required to determine the safety and tolerability of CBD, the maximum tolerated dose, and to examine the effect of food on CBD PK parameters.

OBJECTIVE:This trial assessed the safety, tolerability and PK of CBD oral solution in healthy adult volunteers, as well as the effect of food on CBD PK parameters.

METHODS:The study consisted of three arms: single ascending dose (1500, 3000, 4500 or 6000 mg CBD [n = 6 per group]/placebo [n = 8; 2 per CBD dose group]), multiple dose (750 or 1500 mg CBD [n = 9 per group]/placebo [n = 6; 3 per CBD dose group] twice daily), and food effect (1500 mg CBD single dose [n = 12]). All subjects completed all trial arms and were analyzed as planned.

RESULTS:CBD was generally well tolerated. Diarrhea, nausea, headache, and somnolence were the most common adverse events (AEs) across all trial arms, with an increased incidence of some gastrointestinal and nervous system disorder AEs (most notably diarrhea and headache) apparent in subjects taking CBD compared with placebo. All AEs were of mild or moderate severity; none were severe or serious. There were no deaths or discontinuations in the trial. After single oral doses, CBD appeared rapidly in plasma; time to maximum plasma concentration (tmax) was approximately 4-5 h. The major circulating metabolite was 7-carboxy-CBD, then parent CBD, 7-hydroxy-CBD (active metabolite), and 6-hydroxy-CBD (a relatively minor metabolite). Plasma exposure to CBD [maximum plasma concentration (Cmax) and area under the plasma concentration-time curve from time zero to time t (AUCt)] increased in a less than dose-proportional manner (Cmax slope 0.73; AUCt slope 0.64). Oral clearance of CBD was high (1111-1909 L/h) and apparent volume of distribution was large (20,963-42,849 L). CBD reached steady state after approximately 2 days, with moderate accumulation (1.8- to 2.6-fold) after 750 and 1500 mg CBD twice daily. After 7 days, a twofold increase in CBD dose resulted in 1.6- and 1.9-fold increases in geometric mean Cmax and area under the plasma concentration-time curve over a dosing interval (AUCτ), respectively. CBD elimination was multiphasic; the terminal elimination half-life was approximately 60 h after 750 and 1500 mg CBD twice daily; and effective half-life estimates ranged from 10 to 17 h. Cmax was 541.2 ng/mL and AUCτ was 3236 ng·h/mL after 1500 mg CBD twice daily. A high-fat meal increased CBD plasma exposure (Cmax and AUCt) by 4.85- and 4.2-fold, respectively; there was no effect of food on tmax or terminal half-life.

CONCLUSION:CBD was generally well tolerated. Most AEs were mild in severity; none were severe or serious. The safety and PK profile support twice-daily administration of CBD.

Exhibit D

https://www.ncbi.nlm.nih.gov/pubmed/31133833

Front Behav Neurosci. 2019 May 7;13:94. doi: 10.3389/fnbeh.2019.00094. eCollection 2019.Prolonged Cannabidiol Treatment Lacks on Detrimental Effects on Memory, Motor Performance and Anxiety in C57BL/6J Mice.Schleicher EM1, Ott FW1, Müller M1, Silcher B1, Sichler ME1, Löw MJ1, Wagner JM1, Bouter Y1.Author informationAbstractThe Cannabis plant contains more than 100 currently known phytocannabinoids. Regarding the rising consumption of the non-psychotropic phytocannabinoid cannabidiol (CBD) in people's everyday life (e.g., beauty products, food and beverages), the importance of studies on the influence of CBD on healthy humans and rodents is evident. Therefore, the behavioral profile of CBD was investigated with a battery of behavioral tests, including motor, anxiety, and memory tests after prolonged CBD treatment. Adult C57Bl/6J wildtype (WT) mice were daily intraperitoneally injected with 20 mg/kg CBD for 6 weeks starting at two different points of ages (3 months and 5 months) to compare the influence of prolonged CBD treatment with a washout period (former group) to the effects of long term CBD treatment (current group). Our results show that CBD treatment does not influence motor performance on an accelerating Rotarod test, while it also results in a lower locomotor activity in the open field (OF). No influence of CBD on spatial learning and long term memory in the Morris Water Maze (MWM) was observed. Memory in the Novel Object Recognition test (NORT) was unaffected by CBD treatment. Two different anxiety tests revealed that CBD does not affect anxiety behavior in the Dark-Light Box (DLB) and OF test. Although, anxiety is altered by current CBD treatment in the Elevated Plus Maze (EPM). Moreover, CBD-treated C57Bl/6J mice showed an unaltered acoustic startle response (ASR) compared to vehicle-treated mice. However, current CBD treatment impairs prepulse inhibition (PPI), a test to analyze sensorimotor gating. Furthermore, prolonged CBD treatment did not affect the hippocampal neuron number. Our results demonstrate that prolonged CBD treatment has no negative effect on the behavior of adult C57Bl/6J mice.

Prolonged Cannabidiol Treatment has no Detrimental Effects on Memory, Motor Performance and Anxiety in Mice. Mice were daily intraperitoneally injected with 20 mg/kg CBD for 6 weeks. Our results show that CBD treatment does not influence motor performance, spatial learning and long term memory, anxiety under stress, or hippocampal neuron number. Our results demonstrate that prolonged CBD treatment has no negative effect on the behavior of adult mice. Front Behav Neurosci. 2019 May 7;13:94. https://is.gd/OrmfDX

Exhibit E

1. Epilepsy Behav. 2018 Nov;88:162-171. doi: 10.1016/j.yebeh.2018.07.027. Epub 2018 Oct 2.

Abuse potential assessment of cannabidiol (CBD) in recreational polydrug users: Arandomized, double-blind, controlled trial.

Schoedel KA(1), Szeto I(2), Setnik B(3), Sellers EM(4), Levy-Cooperman N(5),Mills C(6), Etges T(7), Sommerville K(8).

Author information: (1)Altreos Research Partners Inc., 50 Wanda Road, Toronto, ON, M6P1C6, Canada.Electronic address: [email protected].(2)Syneos Health, 3201 Beechleaf Court, Suite 600, Raleigh, NC 27604-1547,USA(1).(3)Syneos Health, 3201 Beechleaf Court, Suite 600, Raleigh, NC 27604-1547,USA(1); University of Toronto, Department of Pharmacology and Toxicology, MedicalSciences Building, Room 4207, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada. Electronic address: [email protected].(4)University of Toronto, Department of Pharmacology and Toxicology, MedicalSciences Building, Room 4207, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada.(5)Altreos Research Partners Inc., 50 Wanda Road, Toronto, ON, M6P1C6, Canada.Electronic address: [email protected].(6)Syneos Health, 720 King Street West, 7th Floor, Toronto, ON M5V 2T3, Canada.Electronic address: [email protected].(7)GW Research Ltd., Cambridge, UK. Electronic address: [email protected].(8)Greenwich Biosciences, Inc., Carlsbad, CA, USA. Electronic address:[email protected].

RATIONALE: Treatment with a highly purified oral solution of cannabidiol (CBD),derived from the plant Cannabis sativa L., demonstrated some evidence of central nervous system (CNS)-related adverse events in patients enrolled in phase 3trials for treatment of childhood-onset epilepsy. Cannabidiol was categorized as a Schedule 1 substance by the United States Drug Enforcement Administration;therefore, it was important to test CBD for human abuse potential.METHODS: This was a single-dose, randomized, double-blind, double-dummy, placebo-and active-controlled crossover trial. The abuse potential of single oral dosesof plant-derived pharmaceutical formulations of highly purified CBD (Epidiolex®; 750 mg, 1500 mg, and 4500 mg) was compared with that of single oral doses ofalprazolam (2 mg), dronabinol (10 mg and 30 mg), and placebo in healthyrecreational polydrug users. The primary endpoint to assess abuse potential wasthe maximum effect (Emax) on Drug-Liking visual analog scale (VAS). Othermeasurements included Emax on Overall Drug-Liking VAS, Take Drug Again VAS,positive and negative effects, other subjective effects, and Drug Similarity VAS.Cognitive and psychomotor functions were assessed using the Divided AttentionTest, the Hopkins Verbal Learning Test-Revised, and the Digit-Symbol SubstitutionTask. Pharmacokinetic parameters were determined for CBD and its majormetabolites. Standard safety measures and adverse events were assessed.PRINCIPAL RESULTS: Of 95 eligible subjects, 43 qualified for the treatment phase,received at least 1 dose of investigational medicinal product, and were included in safety assessments; 35 subjects were included in the pharmacodynamic analysis.Subjects receiving alprazolam and dronabinol had significantly higher Drug-LikingEmax (P < 0.0001) compared with those receiving placebo, confirming studyvalidity. Compared with placebo, Drug-Liking was not significantly different for subjects taking 750-mg CBD (P = 0.51). Drug-Liking Emax values for 1500-mg and4500-mg CBD were significantly different from placebo (P = 0.04 and 0.002,respectively); however, the mean differences were <10 points on VAS compared with>18-point differences between positive controls and placebo. Alprazolam anddronabinol had significantly higher Drug-Liking, Overall-Liking, and Take DrugAgain VAS Emax values compared with all doses of CBD (P ≤ 0.004). In contrast to alprazolam, CBD administration had no observable effect on cognitive/psychomotor tests. Pharmacokinetic parameters for CBD in this trial were consistent withprevious studies. The majority of adverse events reported during the trial wereof mild or moderate severity; no serious adverse events or deaths were reported.CONCLUSION: Administration of a therapeutic dose of CBD (750 mg) showedsignificantly low abuse potential in a highly sensitive population of polydrugusers. Although high and supratherapeutic doses of CBD (1500 mg and 4500 mg,respectively) had detectable subjective effects compared with placebo; theeffects were significantly lower than those observed with alprazolam anddronabinol.

Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

DOI: 10.1016/j.yebeh.2018.07.027 PMID: 30286443 [Indexed for MEDLINE]

Exhibit F

CANNABIDIOL (CBD)

Critical Review Report

Expert Committee on Drug Dependence

Fortieth Meeting

Geneva, 4-7 June 2018

© World Health Organization 2018

All rights reserved.

This is an advance copy distributed to the participants of the 40th Expert Committee on Drug Dependence, before it has been formally published by the World Health Organization. The document may not be reviewed, abstracted, quoted, reproduced, transmitted, distributed, translated or adapted, in part or in whole, in any form or by any means without the permission of the World Health Organization.

The designations employed and the presentation of the material in this publication do not imply the expression of any opinion whatsoever on the part of the World Health Organization concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. Dotted and dashed lines on maps represent approximate border lines for which there may not yet be full agreement.

The mention of specific companies or of certain manufacturers’ products does not imply that they are endorsed or recommended by the World Health Organization in preference to others of a similar nature that are not mentioned. Errors and omissions excepted, the names of proprietary products are distinguished by initial capital letters.

The World Health Organization does not warrant that the information contained in this publication is complete and correct and shall not be liable for any damages incurred as a result of its use.

Cannabidiol (CBD)

2

Contents

Acknowledgements .................................................................................................................. 4

Summary................................................................................................................................... 5

1. Substance identification ........................................................................................................ 6

A. International Nonproprietary Name (INN) ............................................................................ 6 B. Chemical Abstract Service (CAS) Registry Number .............................................................. 6 C. Other Chemical Names .......................................................................................................... 6 D. Trade Names .......................................................................................................................... 6 E. Street Names........................................................................................................................... 6 F. Physical Appearance.............................................................................................................. 6 G. WHO Review History ............................................................................................................. 6

2. Chemistry ............................................................................................................................... 6

A. Chemical Name ...................................................................................................................... 6 B. Chemical Structure................................................................................................................. 7 C. Stereoisomers ......................................................................................................................... 7 D. Methods and Ease of Illicit Manufacturing............................................................................ 7 E. Chemical Properties............................................................................................................... 9 F. Identification and Analysis ..................................................................................................... 9

3. Ease of Convertibility Into Controlled Substances ............................................................ 10

4. General Pharmacology........................................................................................................ 11

A. Routes of administration and dosage ................................................................................... 11 B. Pharmacokinetics ................................................................................................................. 11 C. Pharmacodynamics .............................................................................................................. 12

5. Toxicology............................................................................................................................ 13

6. Adverse Reactions in Humans ............................................................................................ 13

7. Dependence Potential .......................................................................................................... 14

A. Animal Studies ...................................................................................................................... 14 B. Human Studies...................................................................................................................... 14

8. Abuse Potential.................................................................................................................... 14

A. Animal Studies ...................................................................................................................... 14 B. Human Studies...................................................................................................................... 14

9. Therapeutic Applications and Extent of Therapeutic Use and Epidemiology of Medical

Use........................................................................................................................................ 15

10. Listing on the WHO Model List of Essential Medicines.................................................... 18

11. Marketing Authorizations (as a Medicinal Product) ......................................................... 18

12. Industrial Use ...................................................................................................................... 19

13. Non-Medical Use, Abuse and Dependence ........................................................................ 20

14. Nature and Magnitude of Public Health Problems Related to Misuse, Abuse and

Dependence.......................................................................................................................... 20

15. Licit Production, Consumption and International Trade .................................................. 20

Cannabidiol (CBD)

3

16. Illicit Manufacture and Traffic and Related Information................................................. 20

17. Current International Controls and Their Impact ............................................................. 20

18. Current and Past National Controls ................................................................................... 21

19. Other Medical and Scientific Matters Relevant for a Recommendation on the Scheduling

of the Substance................................................................................................................... 21 References ............................................................................................................................................ 22

Cannabidiol (CBD)

4

Acknowledgements

This report has been drafted under the responsibility of the WHO Secretariat, Department of Essential Medicines and Health Products, Team of Innovation, Access and Use. The report is an update and extension of the pre-review on cannabidiol, that was prepared by Prof Jason White, Adelaide, Australia, for the 39th ECDD meeting in November 2017. The WHO Secretariat would like to thank the following people for their contribution in producing this review report: Dr Sharon Walsh and Dr Susanna Babalonis, Kentucky USA (update and extension search, review and drafting), and J. Rehm et al, Toronto, Canada (analysis on WHO questionnaire for the Review of Psychoactive Substances for the 40th ECDD: evaluation of Cannabidiol, and report drafting).

40th ECDD (2018) Agenda item 4.1

Summary Cannabidiol (CBD)

5

Cannabidiol (CBD) is one of the naturally occurring cannabinoids found in cannabis plants. It is a 21-carbon terpenophenolic compound which is formed following decarboxylation from a cannabidiolic acid precursor, although it can also be produced synthetically.

In experimental models of abuse liability, CBD appears to have little effect on conditioned place preference or intracranial self-stimulation. In an animal drug discrimination model CBD failed to substitute for THC. In humans, CBD exhibits no effects indicative of any abuse or dependence potential.

CBD has been demonstrated as an effective treatment of epilepsy in several clinical trials, with one pure CBD product (Epidiolex®) with completed Phase III trials and under current review for approval in the U.S. There is also preliminary evidence that CBD may be a useful treatment for a number of other medical conditions.

There is unsanctioned medical use of CBD based products with oils, supplements, gums, and high concentration extracts available online for the treatment of many ailments.

CBD is generally well tolerated with a good safety profile. Reported adverse effects may be as a result of drug-drug interactions between CBD and patients’ existing medications.

Several countries have modified their national controls to accommodate CBD as a medicinal product.

To date, there is no evidence of recreational use of CBD or any public health-related problems associated with the use of pure CBD.

6

1. Substance identification

A. International Nonproprietary Name (INN)

Cannabidiol

B. Chemical Abstract Service (CAS) Registry Number

13956-29-1 [1]

C. Other Chemical Names

CBD; 2-[1R-3-methyl-6R-(1-methylethenyl)-2-cyclohexen-1-yl]-5-pentyl-1,3- benzenediol; [2]

D. Trade Names

Epidiolex® (in development) Arvisol® (in development)

E. Street Names

No data available

F. Physical Appearance

A crystalline solid [2]

G. WHO Review History

The 38th ECDD recommended that pre-review documentation on cannabis-related substances, including cannabidiol, be prepared and evaluated at a subsequent committee meeting [3]. Cannabidiol has been pre-reviewed by the 39th WHO Expert Committee on Drug Dependence (ECDD) in November 2017. This review is an expansion and update of that initial pre-review report.

2. Chemistry

A. Chemical Name

IUPAC Name: 2-[(6R)-3-methyl-6-prop-1-en-2-ylcyclohex-2-en-1- yl]-5-pentylbenzene-1,3-diol

7

B. Chemical Structure

Molecular Formula: C21H30O2 Molecular Weight: 314.469 g/mol

C. Stereoisomers

Cannabidiol (CBD) is normally taken to refer to the naturally occurring (-)- enantiomer. (+) CBD has been synthesized [4] but has received little attention.

(+) CBD has been shown to have modest affinity at CB1 and CB2 receptors unlike (-) CBD ((+)-CBD Ki= 0.84 µM at CB1), whereas both compounds inhibited anandamide hydrolysis and were agonists at the vanilloid type 1 (VR1) receptor at which capsaicin acts. [5] The (+)-CBD isomer was more active than the (-)-CBD-isomer as an anticonvulsant agent in a mouse seizure model. [6] However, to date, there is no substantive evidence as to whether (+)-CBD is likely to cause THC-like psychoactive effects.

D. Methods and Ease of Illicit Manufacturing

Synthesis of CBD in vitro: Synthetic routes are available for the production of CBD, but some of the published methods yield only small amounts of CBD. The two most efficient routes are:

1) The condensation of (+)-e-mentha-diene-l-01 with olivetol in the presence

of weak acids (oxalic, picric or maleic acid). The isomer obtained in this reaction may be converted to CBD with BF3-etherate by a retro-Friedel- Crafts reaction, followed by recombination. However, with this reagent the reaction proceeds further causing cyclisation of CBD to delta-1-THC and iso-THC [7]

2) A one step reaction for CBD synthesis utilizes boron trifluoride (BF3)-

etherate on alumina as condensing reagent in the reaction of (+)-e-mentha- diene-l-01 with olivetol on a 0.8mmol scale (refer to Figure 1). This results in CBD as the major product, with 55% yield as chromatographically pure

8

Figure 1: Synthesis of CBD with boron trifluoride (BF3)-etherate taken

oil or 41% yield as crystalline material. On a 100mmol scale, the yields were 46% as an oil, and 37% as crystalline material. [8]

from Mechoulam et al 2002 [9]

Synthesis of CBD in plants:

Cannabis cultivars range from those grown to produce cannabis for recreational purposes to those produced in order to use hemp fibre derived from the stems of the plant. In cultivars utilized for recreational purposes, the quantity of THC exceeds that of CBD in the dried female inflorescences used for smoking and oral administration. Hemp cultivars produce substantially less THC and higher levels of CBD. [10] Unsanctioned production of cannabis cultivars with high CBD levels does occur for purposes of medical treatment rather than recreational use (refer to Section 13).

In plants, THC and CBD are derived from their acidic precursors Δ9- tetrahydrocannabinolic acid (THCA) and cannabidiolic acid (CBDA) (refer to Figure 2). THCA and CBDA are both derived from cannabigerolic acid (CBGA). The final step differs, with THCA synthase and CBDA synthase producing THCA or CBDA, respectively, from CBGA. Subsequent decarboxylation of THCA and CBDA via light exposure, heating, or aging, results in THC or CBD. [10-12]

9

Figure 2: Biogenesis of THC and CBD adapted from Taura et al. (2007) THCA synthase and CBDA synthase catalyze oxidative cyclization of the monoterpene moiety of CBGA to form THCA and CBDA, respectively. THC and CBD are generated from THCA and CBDA by non‐enzymatic decarboxylation. [11]

In addition to genetic characteristics, cultivated plants are influenced by environmental conditions and production technology during their life cycle. A study evaluating the effects of ambient temperature and humidity, soil temperature and precipitation on the content of THC and CBD in industrial hemp noted that these agroclimatic conditions have differing effects on THC and CBD. For example, CBD content is positively affected by soil temperature and ambient temperature, but negatively influenced by precipitation [13]

E. Chemical Properties

Melting point: 62-63°C Solubility: approx. 23.6 mg/mL in DSMO and ethanol [14]

F. Identification and Analysis

There are a number of published methods for the analytical detection of CBD in various biological samples. For example,

▪ spectrophotometric determination [15];

▪ liquid chromatography–tandem mass spectrometry (LC–MS/MS)

detection of CBD in whole blood [16, 17] samples;

10

▪ high performance (HP) LC-MS/MS methods for CBD detection in hair [18], urine [19] and plasma [20] samples;

▪ gas chromatography mass spectrometry (GC-MS) detection of CBD in

hair [21, 22], oral [23] and plasma [24] samples;

▪ 2-dimensional-GC-MS methods for detection in oral fluid [25], plasma [26] and post mortem blood samples [27].

3. Ease of Convertibility into Controlled Substances

There is some evidence that CBD can be converted to tetrahydrocannabinol (THC), a Schedule 1 substance under the United Nations Convention on Psychotropic Substances 1971. Two main methods have been reported. There have also been reports suggesting this transformation can occur spontaneously in vivo; however, additional research has indicated that this finding may be limited to specific experimental conditions and likely does not occur when oral CBD is administered to humans.

Conversion in the laboratory

Under experimental conditions, it has been demonstrated that heating CBD in solutions of some acids catalyses cyclizations within the CBD molecule resulting in delta-9-THC [28]. Gaoni and Mechoulam have published several papers regarding methods of converting CBD to other cannabinoids including THC, however the yields vary, and purity is unclear. [9]

A patent (US 2004/0143126 A1) on the conversion of CBD to delta-9-THC details a method involving the addition of BF3Et2O (50 µl), under nitrogen atmosphere, to an ice cold solution of CBD (300 mg) in dry methylene chloride (15 ml). The solution is stirred at 0° C for 1 hour, followed by the addition of saturated aqueous solution of NaHCO3 (2 ml) until the red colour fades. The organic layer is removed, washed with water, dried over MgSO4 and evaporated. The composition of the oil obtained (determined by HPLC) is: trans-delta8-isoTHC 27%, delta-9-THC 66.7%. The oil is then chromatographed on silica gel column (20 g) and eluted with petroleum ether followed by graded mixtures, up to 2:98 of ether in petroleum ether. The first fraction eluted was the delta8-isoTHC (30 mg, 9.5%) followed by a mixture of delta8-iso THC and delta-9-THC (100 mg). The last compound to be eluted was the delta-9-THC (172 mg, 57%). The purity of delta-9-THC (as determined by HPLC) is 98.7%. [29]

Spontaneous conversion

There is some limited evidence that the conversion of CBD to delta-9-THC in the presence of acid could occur in the human gut. Two in vitro studies have used simulated gastric fluid to demonstrate the potential for this conversion. One in vitro study reported the formation of delta-9-THC along with other cannabinoid products in artificial gastric juice without pepsin. The conversion rate of CBD to THC was only 2.9%. [30]. A more recent publication reported the formation of delta-9-THC and delta-8-THC when CBD was exposed to simulated gastric fluid without enzymes at 37ºC. [31] This study was supported by Zynerba Pharmaceuticals, a company that is developing a transdermal CBD gel (which bypasses gastric involvement and possible conversion). Moreover, a follow-up commentary to this report [32] was also

11

published (also supported by Zynerba), which suggested that this conversion occurs in humans after oral administration and also suggested that earlier observations from in vivo data of barely detectable concentrations of THC after CBD administration would produce physiological relevant effects in humans. There is little to no evidence that this conversion occurs in vivo after oral administration of CBD. A recent study examined gastric and plasma concentrations of cannabinoids in minipigs after repeated CBD administration (15 mg/kg/day for 5 days). The results indicated no THC or THC metabolites in plasma or gastric fluid matrices after CBD administration. [33] However, this study was supported by GW Pharmaceuticals, a company with an oral CBD product under development.

Overall, there is no evidence that this transformation occurs in humans after oral CBD administration. One human study administered 600 mg of CBD to healthy participants and detected no THC and trace concentrations of THC metabolites (11-OH-THC, THC-COOH). [34] Similarly, chronic administration of CBD does not result in detectable THC concentrations in plasma; for example, in a six-week clinical study in Huntington’s disease patients who were administered CBD 10 mg/kg/day (approximately 700 mg/day), CBD average plasma concentration range was 5.9-11.2 ng/mL with no delta-9-THC detected. [35]. In general, clinical studies have reported that even high doses of oral CBD do not cause THC-like effects (e.g., impairment, increased heart rate/tachycardia, dry mouth).[36] For example, in a study of healthy volunteers administered 200 mg oral CBD, CBD did not produce any impairments of motor or psychomotor performance.[37] A number of other studies involving high doses of CBD were recently summarised by Grotenhermen et al.[36] and Nahler et al.[38]; they concluded that high doses of oral CBD consistently fail to demonstrate significant effects or demonstrate effects opposite to those of THC. Overall, there is no evidence of that oral CBD administration in humans results in clinically relevant THC-like subjective or physiological effects, or appreciable plasma concentrations of THC or its metabolites.

4. General Pharmacology

A. Routes of administration and dosage

Currently there are no approved marketed pure CBD medicinal products, although several are in development (refer to Section 11).

In clinical trials and research studies, CBD is generally administered orally as either a capsule, or dissolved in an oil solution (e.g. olive or sesame oil). It can also be administered through sublingual or intranasal routes. A wide range of oral doses have been reported in the literature, with most from 100- 800mg/day. [39]

B. Pharmacokinetics

Oral delivery of an oil-based capsule formulation of CBD has been assessed in humans. Probably due to its poor aqueous solubility, the absorption of CBD from the gastrointestinal tract is erratic, and the resulting pharmacokinetic profile is variable. Bioavailability from oral delivery was estimated to be 6% due to significant first-pass metabolism. [40] In healthy male volunteers, the

12

mean±SD whole blood levels of CBD at 1, 2 and 3 hours after administration of 600mg oral CBD were reported to be 0.36 (0.64) ng/mL, 1.62 (2.98) ng/mL and 3.4 (6.42) ng/mL, respectively. [34] A recent study reported that CBD, when given at doses of 5, 10 and 20 mg/kg/d to children ages 4-10 with Dravet syndrome, produced dose-proportional increases in area-under-the-curve plasma concentrations for CBD and its metabolites, 6-OH-CBD, 7-OH-CBD, and 7-COOH-CBD. [41] Aerosolised CBD has been reported to yield rapid peak plasma concentrations in 5–10 minutes and higher bioavailability than oral administration.

CBD is rapidly distributed into the tissues with a high volume of distribution of ~32L/kg. Like THC, CBD may preferentially accumulate in adipose tissues due to its high lipophilicity. [39, 42]

CBD is extensively metabolised in the liver. The primary route is hydroxylation to 7-OH-CBD which is then metabolised further resulting in a number of metabolites that are excreted in faeces and urine. [40] A study in human liver microsomes (HLMs) demonstrated that CBD was metabolized by pooled HLMs to eight monohydroxylated metabolites (6α-OH-, 6β-OH-,7- OH-, 1”-OH-, 2”-OH-, 3”-OH-, 4”-OH-, and 5”-OH-CBDs). Among these metabolites, 6α-OH-, 6β-OH-, 7-OH-, and 4”-OH-CBDs were the major ones. Seven recombinant human CYP enzymes were identified as capable of metabolising CBD: CYP1A1, CYP1A2, CYP2C9, CYP2C19, CYP2D6, CYP3A4, and CYP3A5. The two main isoforms involved are CYP3A4 and CYP2C19. [43]

In a number of studies, CBD has been shown to inhibit CYP isozymes in vitro, but it is not clear that this occurs at concentrations achieved with doses used clinically.

C. Pharmacodynamics

There are two main cannabinoid (CB) receptors, CB1 which is primarily located in the central nervous system with some expression in peripheral tissues and CB2 receptors, which can be found in the periphery on cells with immune function and in the gastrointestinal tract and at low densities in the central nervous system.

CBD does not appear to act directly at CB1 receptors, with a number of studies reporting that there is no measurable response in binding assays. In studies examining potential agonist effects at CB1 receptors, most find no effect, with one report of a weak agonist and one of a weak antagonist effect, each at high concentrations (>10uM). CBD also shows low affinity at CB2 receptors. [44]

Across a range of measures in humans and animals, CBD had been shown to have very different effects from those of THC. In mice, CBD failed to produce the behavioral characteristics (e.g. suppression of locomotor activity, hypothermia, antinociception) associated with CB1 activation, whereas THC generated all of the effects which occur when CB1 is activated. [45, 46] Neuroimaging studies in humans and animals have shown that CBD has effects which are generally opposite to those of THC. [47] In contrast to THC, CBD has no effect on heart rate or blood pressure under normal conditions, but in animal models of stress it reduces heart rate and blood pressure. [48] Other differences between THC and CBD are discussed below.

13

Some studies have shown that CBD may reduce or antagonize some of the effects of THC. The mechanism for this is unclear, with some suggesting that it may be a weak CB1 antagonist. Recent evidence suggests that it may be a negative allosteric modulator of the CB1 receptor, thereby acting as a non- competitive antagonist of the actions of THC and other CB1 agonists. [44, 49] A recent study suggests that CBD may also act as an allosteric modulator at the CB2 receptor. [50]

CBD may also interact with the endocannabinoid system through indirect mechanisms such as enhanced action of the endogenous cannabinoid ligand anandamide. This results from blockade of anandamide reuptake and the inhibition of its enzymatic degradation. [5, 9, 43]

CBD has been shown to modulate several non-endocannabinoid signaling systems. It is not clear which, if any, of these mechanisms are responsible for any of CBD’s potential clinical or other effects. Some of these mechanisms include [51]:

• Inhibition of adenosine uptake, possibly resulting in indirect agonist activity at adenosine receptors.

• Enhanced activity at the 5-HT1a receptor. • Enhanced activity at glycine receptor subtypes • Blockade of the orphan G-protein-coupled receptor GPR55

5. Toxicology

The potential toxic effects of CBD have been extensively reviewed [52] with a recent update of the literature. [53] In general, CBD has been found to have relatively low toxicity, although not all potential effects have been explored. The following are some of the relevant findings to date from in vitro and animal studies:

• CBD affects growth of tumoral cell lines, but has no effect in most non- tumour cells. However, a pro-apoptotic effect has been observed in lymphocytes.

• It has no effect on embryonic development (limited research) • Evidence on potential hormonal changes is mixed, with some evidence of

possible effects and other studies suggesting no effect, depending on the method used and the particular hormone

• It has no effect on a wide range of physiological and biochemical parameters or significant effects on animal behaviour unless extremely high doses are administered (e.g., in excess of 150 mg/kg iv as an acute dose or in excess of 30 mg/kg orally daily for 90 days in monkeys)

• Effects on the immune system are unclear; there is evidence of immune suppression at higher concentrations, but immune stimulation may occur at lower concentrations.

• There is potential for CBD to be associated with drug interactions through inhibition of some cytochrome P450 enzymes, but it is not yet clear whether these effects occur at physiological concentrations.

6. Adverse Reactions in Humans

As noted above, CBD does not produce the effects that are typically seen with cannabinoids such as THC. It also failed to produce significant effects in a human

14

study of abuse potential discussed below. [34] Across a number of controlled and open label trials CBD of the potential therapeutic effects of CBD it is generally well

15

tolerated, with a good safety profile. [39, 53] Clinical trials involving use of CBD for treatment of epilepsy will be discussed in Section 9: Therapeutic Applications.

7. Dependence Potential

A. Animal Studies

Male mice were injected i.p. once a day for 14 days with either CBD (0.1, 1, or 3mg/kg) or delta-9-THC (1, 3, or 10mg/kg). Tolerance to the effects of THC was observed, however no tolerance to CBD at any of the dosages was observed. [54] No studies of the physical dependence potential of CBD in animals were identified.

B. Human Studies

Controlled, human studies regarding the potential physical dependence effects (e.g. withdrawal and tolerance) of cannabidiol have not been reported.

8. Abuse Potential

A. Animal Studies

In male Sprague-Dawley rats, administration of low dose (5 mg/kg) CBD did not change the threshold frequency required for intracranial self-stimulation (ICSS). However, high dose (10 mg/kg and 20 mg/kg) CBD resulted in an elevation of the threshold suggestive of diminished reward activity. This effect is opposite to that of drugs of abuse such as cocaine, methamphetamine and opioids which lower the threshold. [55]

Increased dopamine release in cells of the mesolimbic ventral tegmental area – nucleus accumbens pathway is a common effect characteristic of almost all drugs of abuse. While THC has been shown to increase the firing rate of these cells, cannabidiol had no effect. [56]

It appears that CBD given alone has little effect on conditioned place preference (CPP). For example, Long-Evans rats treated with 10 mg/kg CBD showed neither CPP nor CPA. [57] However, rats treated with increasing doses of CBD and THC (1, 3, and 10 mg/kg) exhibited a trend towards CPP not seen in those given THC alone. [58] The authors attributed this to a pharmacokinetic interaction leading to higher THC concentrations rather than a change in receptor action.

CBD appears not to exhibit THC-like discriminative stimulus effects. For example, in rats trained to discriminate THC from vehicle, CBD did not substitute for THC at any dose tested [57]. CBD also failed to substitute for THC in pigeons trained to discriminate THC from vehicle. [59]

B. Human Studies

While the number of studies is limited, the evidence from well controlled human experimental research indicates that CBD is not associated with abuse potential.

16

Single dose administration of cannabidiol has been evaluated in healthy volunteers using a variety of tests of abuse potential as well as physiological effects in a randomised double blind placebo-controlled trial. [34] An orally administered dose of 600mg of CBD did not differ from placebo on the scales of the Addiction Research Centre Inventory, a 16 item Visual Analogue Mood Scale, subjective level of intoxication or psychotic symptoms. In contrast, THC (10mg oral) administration was associated with subjective intoxication and euphoria as well as changes in ARCI scales reflecting sedation and hallucinogenic activity. THC also increased psychotic symptoms and anxiety. While THC increased heart rate, CBD had no physiological effects.

A randomized, double-blind, within-subject laboratory study was undertaken to assess the influence of CBD (0, 200, 400, 800mg, p.o.) pre-treatment on the effects of inactive (0.01% THC) and active (5.30–5.80% THC) smoked cannabis. Healthy cannabis smokers (n=31) completed eight outpatient sessions with CBD administered 90min prior to cannabis administration. Under placebo CBD conditions, active cannabis was self-administered by significantly more participants and produced significant, time-dependent increases in subjective ratings and heart rate relative to inactive cannabis. CBD alone produced no significant psychoactive, cardiovascular or other effects. Cannabis self-administration, subjective effects, and cannabis ratings did not vary as a function of CBD dose relative to placebo capsules. These findings suggest that oral CBD does not reduce the reinforcing, physiological, or positive subjective effects of smoked cannabis. [60]

The authors of the study then undertook a second analysis of this data to examine the abuse liability profile of oral cannabidiol in comparison to oral placebo and active smoked cannabis. The results of this analysis demonstrated that CBD was placebo-like on all measures (including visual analogue scales, psychomotor performance such as the digit symbol substitution task, heart rate and blood pressure) compared to active cannabis, which produced abuse- related subjective effects as well as a range of other effects. [61]

9. Therapeutic Applications and Extent of Therapeutic Use and

Epidemiology of Medical Use Epilepsy

The clinical use of CBD is most advanced in the treatment of epilepsy. In clinical trials, CBD has been demonstrated as an effective treatment for at least some forms of epilepsy, with one pure CBD product (Epidiolex®) currently in Phase III trials.

The use of CBD for this purpose is based on a number of studies in animals dating back to the 1970s. [62] These studies demonstrated the anti-seizure activity of cannabidiol in a number of animal models. Based on this research, cannabidiol has been tested in patients with epilepsy.

In a very early small-scale double-blind placebo-controlled trial, patients received either 200 mg CBD daily (4 patients) or placebo (5 patients) for a 3-month period, in addition to their habitual medication. In the CBD group, two patients had no seizures for the entire 3-month period, one partially improved, and the fourth had no

17

improvement. No improvements were observed in the placebo group and no toxic effects were reported for either group. This study has a number of limitations, including the small sample size, unclear design as to blinding, and lack of definition of partial improvement. [63]

In another study, 15 patients with “secondarily generalized epilepsy with temporal focus,” were randomly divided into two groups. In a double-blind procedure, each patient received 200-300 mg daily of CBD or placebo for up to four and a half months in combination with their existing prescribed antiepileptic medications (which were no longer effective in the control of their symptoms). CBD was tolerated in all patients, with no signs of toxicity or serious side effects. Of the eight participants in the CBD treatment group, four were reported to be almost free of seizure episodes throughout the trial, whereas three others showed partial clinical improvement. CBD was ineffective in one patient. In comparison, the clinical condition of seven placebo patients remained unchanged with one patient showing improvement. [64]

There have also been some negative reports regarding the effectiveness of CBD. In a trial reported in 1986, a dose of CBD of 200–300 mg/day for a month resulted in no significant differences between the treatment and placebo groups. [65] Similarly, a 6- month double blind study administering CBD 100 mg 3 times each day did not result in any changes in seizure frequency or improvement in cognition or behaviour. [66]

The results of several trials examining the effects of CBD in patients with severe, intractable, childhood-onset, treatment-resistant epilepsy have been reported. The first was an open label study of 214 patients (aged 1–30 years) who were receiving stable doses of antiepileptic drugs before study entry. Patients were given oral cannabidiol, initially at 2–5 mg/kg per day, and then titrated until intolerance or to a maximum dose of 25 mg/kg or 50 mg/kg per day, dependent on study site. The primary measure was the percentage change in the frequency of seizures. In the CBD group, the median monthly frequency of motor seizures reduced from 30·0 at baseline to 15·8 over the 12-week treatment period. The trial was also designed to assess safety, but the absence of a control group means that the results cannot be used to assess the likelihood of CBD producing particular effects. Adverse events reported in more than 10% of patients were somnolence, decreased appetite, diarrhoea, fatigue, and convulsion. Five (3%) patients discontinued treatment because of an adverse event. Serious adverse events were reported in 48 (30%) patients, of which 20 (12%) experienced severe adverse events possibly related to cannabidiol use, the most common of which was status epilepticus (n=9 [6%]). [67]

The same research group reported the results of a controlled trial of CBD treatment for Dravet syndrome, a complex childhood epilepsy disorder that is associated with drug-resistant seizures and a high mortality rate. In a double-blind, placebo-controlled trial, 120 children and young adults with Dravet syndrome were randomly assigned to receive either cannabidiol oral solution (20 mg per kilogram per day) or placebo, in addition to standard antiepileptic treatment (a median of 3.0 drugs). The authors reported that cannabidiol decreased the median frequency of convulsive seizures per month from 12.4 to 5.9, as compared with a decrease from 14.9 to 14.1 with placebo. A small percentage (5%) of patients in the CBD group became seizure free as compared to zero in the placebo group. Adverse events that occurred more frequently in the cannabidiol group than in the placebo group included diarrhoea (31% vs 10%), loss of appetite (28% vs 5%) and somnolence (36% vs 10%). Other adverse effects noticed were vomiting, fatigue, pyrexia and abnormal results on liver-function tests.

18

Adverse effects led to the withdrawal of eight patients in the cannabidiol group compared with one in the placebo group. [68] A similar study was recently conducted and reported on the safety and efficacy of CBD in patients with Lennox-Gastaut syndrome, a severe form of epileptic encephalopathy that produces various types of seizures (including drop seizures) that are often treatment-resistant. Across 24 clinical sites (located in US, the Netherlands and Poland), a total of 171 patients ages 2-55 years old, were randomized to receive active CBD [200 mg/kg, oral solution] (n=86) or matched placebo (n=85) as an add-on to their antiepileptic regimen (average of 3 medications/patient in each group). CBD was administered daily for 14 weeks: 2 weeks of dose escalation (starting dose of 2.5 mg/kg, PO) and 12 weeks of maintenance (200 mg/kg, PO); a 10-day dose taper was also included at the end of treatment. The authors report that CBD treatment decreased drop seizure frequency by a median of 43.9% (71.4 seizures per patient/month at baseline; 31.4 during treatment), compared to a 21.8% reduction in the placebo group (74.7 at baseline, 56.3 during treatment). CBD also increased the number of patients experiencing ≥50% reduction in drop seizure frequency (44% patients (n=38) in the CBD group compared to 24% (n=20) in the placebo group). CBD also reduced other non-drop seizures (49.4% reduction in CBD group, 22.9% in the placebo group). A small number of patients in the CBD group (n=3) were seizure free during the 12 weeks of maintenance dosing, compared to zero in the placebo group. Treatment related adverse events occurred more frequently in the cannabidiol group than in the placebo group and were similar to those reported in previous trials: diarrhoea (13% vs 4%), somnolence (14% vs. 8%), decreased appetite (9% vs 1%), vomiting (7% vs. 5%) and pyrexia (1% in both groups). Increases in liver function tests (>3 times the upper limit of normal) occurred in 20 patients in the CBD group and 1 patient in the placebo group. [69] It has been suggested that some of the adverse effects of cannabidiol observed in the clinical studies may relate to interactions with other antiepileptic drugs. For example, a recent study evaluated thirteen subjects with refractory epilepsy concomitantly taking clobazam and CBD. Nine of 13 subjects had a >50% decrease in seizures, corresponding to a responder rate of 70%. Side effects were reported in 10 (77%) of the 13 subjects, but were alleviated with clobazam dose reduction. All subjects tolerated CBD well. [70]

Cannabidiol (as Epidiolex®; GW Pharmaceuticals) was submitted in 2017 for regulatory approval to the U.S. Food and Drug Administration for treatment of seizures related to Lennox-Gastaut and Dravet syndromes in patients two years of age and older. A public advisory committee was held in April 2018 with the committee voting in favor of approval of CBD; while the committee approval is not binding but rather advisory, it is most common for the FDA to concur with committee votes.

Other indications

There is also evidence that CBD may be a useful treatment for a number of other medical conditions. However, this research is considerably less advanced than for treatment of epilepsy. For most indications, there is only pre-clinical evidence, while for some there is a combination of pre-clinical and limited clinical evidence. The range of conditions for which CBD has been assessed is diverse, consistent with its neuroprotective, antiepileptic, hypoxia-ischemia, anxiolytic, antipsychotic, analgesic, anti-inflammatory, anti-asthmatic, and antitumor properties. [39, 53, 71] The evidence for some of these indications was recently reviewed by Pisanti et al., .[72]

19

Additionally, recent human studies have reported a therapeutic signal for CBD for transplant acceptance (decreasing the development of graft vs. host disease after hematopoietic cell transplants) [73] and reducing some of the positive symptoms of schizophrenia (1000 mg/day, PO) [74]. Other recent reports have failed to demonstrate CBD efficacy to reduce symptoms of ulcerative colitis (up to 500 mg/day, PO) [75], chronic pain in kidney transplant patients (50 – 300 mg/day, PO) [76], and experimentally-induced anxiety (600 mg, PO). [77]

Another possible therapeutic application which has been investigated is the use of CBD to treat drug addiction. A recent systematic review concluded that there were a limited number of preclinical studies which suggest that CBD may have therapeutic properties on opioid, cocaine, and psychostimulant addiction, and some preliminary data suggest that it may be beneficial in cannabis and tobacco addiction in humans. However, considerably more research is required to evaluate CBD as a potential treatment. [78]

10. Listing on the WHO Model List of Essential Medicines Cannabidiol is not listed on the WHO Model List of Essential Medicines (20th List) or the WHO Model List of Essential Medicines for Children (6th List). [79]

11. Marketing Authorizations (as a Medicinal Product)

There are currently no authorized pure CBD products. However, there are several in development. Epidiolex® is a liquid oral formulation of pure plant-derived CBD. It is produced by GW Pharmaceuticals in the United Kingdom and has shown positive results in Phase 3 trials for Dravet and Lennox-Gastaut syndromes, which are both treatment-resistant seizure disorders. The published results related to this therapeutic application are covered in Section 9: Therapeutic Applications. [67-70] Arvisol® is an oral tablet containing pure CBD. It has been developed by Echo Pharmaceuticals in the Netherlands and is intended to be registered for the treatment of various neurological disorders, including schizophrenia and epilepsy. Arvisol® is still undergoing Phase I clinical trials and is not yet available as a medicinal product. [80] Zynerba® Pharmaceuticals is developing a CBD gel (ZYN002) that is designed for transdermal use. The target indications for ZYN002 are Fragile X syndrome, adult refractory focal epilepsy and encephalopathies that are developmental and epileptic in nature. This formulation is currently in open-label Phase 2 testing for Fragile X syndrome. Dosing recommendations are to begin at 50 mg/day with increases up to 250 mg/day. [81] Bionorica® (Germany) has developed a pure CBD product that is extracted from hemp plants through a multi-stage process into a crystalline powder (production completed by THC Pharm). [82] STI Pharmaceuticals (Essex, United Kingdom) has developed a crystalline powder of pure synthetic CBD with multiple doses. This product has been evaluated in a Phase II study for its effects on marijuana-induced subjective effects in an oral capsule formulation (200-800 mg). [60] Additionally, STI has produced an aerosolized

20

formulation for inhalation that was assessed using an ad lib dosing design (400 ug/spray) for cigarette smoking . [83] Finally, another study examined CBD dissolved in olive oil as an oral preparation for graft versus host disease. [73] INSYS Pharmaceuticals (United States) has developed an oral solution of pure CBD. It is currently in Phase 2 trials for childhood absence seizures (20-40 mg) and in a Phase 3 trial as an adjunctive therapy in conjunction with vigabatrin for infantile spasm-type seizures. Phase 2 trials are currently registered for Prader-Willi syndrome, and there is open-label access testing for treatment-resistant seizure disorders. This product has also been in a human laboratory trial and evaluated for anxiety-like behavior at doses from 300-900 mg with negative findings .[84] PhytoTech Therapeutics (Tel Aviv, Israel) is developing an oral formulation (PTL101) that contains purified CBD embedded in gelatin matrix pellets. Phase 1 testing has been conducted on this product (10 to 100 mg) and found that it had significantly greater bioavailability compared to a reference product containing CBD (see Sativex® below). [85] Ananda Scientific (Israel) is producing pure CBD for medicinal purposes and reports having their Phase 1 pharmacokinetics studies underway presently in Israel, with numerous other trials planned in Israel and China. [86] In 2015, the US Food and Drug Administration (FDA) granted GW Pharmaceuticals Fast Track designation for intravenous CBD to treat Neonatal Hypoxic-Ischemic Encephalopathy (NHIE).[87] The European Commission also granted orphan designation (EU/3/15/1520) for cannabidiol to be used in the treatment of perinatal asphyxia.[88] NHIE and Perinatal Asphyxia are forms of acute or sub-acute brain injury due to asphyxia caused during the birth process and resulting from deprivation of oxygen during birth (hypoxia). Currently there are no other treatments available for these conditions, but there is evidence of the effectiveness of cannabidiol in animal models. [89] There are numerous CBD products including purported medicinal products, such as pills and capsules for various diseases/symptoms, and also lotions, oils, foods, drinks, shampoos, cosmetics, etc. that are being manufactured and distributed without regulatory oversight and often with unverified contents. [90] The U.S. Food and Drug Administration has issued two major series of warning letters to manufacturers for fraudulent medical claims (describing health benefits with no evidence) and fraudulent production claims (marketing products as containing specified concentrations of CBD when testing demonstrates the absence of CBD). [91] CBD Combination Products CBD is presently marketed in combination with THC in a 1:1 ratio (Sativex®), which is marketed by GW Pharmaceuticals in a number of countries. [92] This combination is sometimes referred to as nabiximols, a name given by the United States Adopted Names (USAN) Council. This product will be covered in a separate ECDD review.

12. Industrial Use

Pure CBD has no legitimate industrial uses.

21

13. Non-Medical Use, Abuse and Dependence

At present, there are no case reports of abuse or dependence relating to the use of pure CBD. There are also no published statistics on non-medical use of pure CBD.

There is unsanctioned medical use of CBD based products. These are produced from high CBD content plants and distributed in a variety of forms, including oils and capsules. These products are sold online as unapproved treatments for a variety of disorders including epilepsy, cancer, AIDS/HIV, anxiety, arthritis, pain, and post- traumatic stress disorder (PTSD). Additionally, CBD is being used in skin and beauty products such as shampoos and skin creams. [93, 94] Also see Annex 1: Report on WHO questionnaire for review of psychoactive substances.

14. Nature and Magnitude of Public Health Problems Related to Misuse, Abuse and Dependence At present no public health problems (e.g. driving under the influence of drugs cases, comorbidities) have been associated with the use of pure CBD.

Also see Annex 1: Report on WHO questionnaire for review of psychoactive substances for the 40th ECDD: evaluation of Cannabidiol.

15. Licit Production, Consumption and International Trade

Licit production of CBD for medical purposes is described in Section 11. Also see Annex 1: Report on WHO questionnaire for review of psychoactive substances for the 40th ECDD: evaluation of Cannabidiol.

16. Illicit Manufacture and Traffic and Related Information

There are no published statistics (e.g. country data on seizures of illicit CBD) currently available. Also see Annex 1: Report on WHO questionnaire for review of psychoactive substances for the 40th ECDD: evaluation of Cannabidiol.

17. Current International Controls and Their Impact

Cannabidiol is not listed in the schedules of the 1961, 1971 or 1988 United Nations International Drug Control Conventions. [95]

However, cannabidiol is being produced for pharmaceutical purposes as an extract of cannabis by GW Pharmaceuticals. Cannabidiol that is produced as an extract of cannabis is currently included in Schedule I of the 1961 Convention.

22

18. Current and Past National Controls

United Kingdom: A statement was issued by the Medicines and Healthcare products Regulatory Agency (MHRA) in 2016 that products containing CBD used for medical purposes are considered as a medicine subject to standard licensing requirements. [96]

United States: CBD is one of many cannabinoids present in cannabis, and as such is in Schedule I of the Controlled Substances Act (Schedule I is the most restricted/ regulated drug class, reserved for medications with a high potential for abuse and no currently accepted medical use).

Canada: CBD is specifically listed in ‘Cannabis, its preparations and derivatives’ as a controlled substance listed in Schedule II Controlled Drugs and Substances Act. However, in 2016 Canada’s Access to Cannabis for Medical Purposes Regulations came into effect. These regulations improve access to cannabis used for medicinal purposes, including CBD. [97]

Australia: In 2015, CBD in preparations for therapeutic use containing 2 per cent or less of other cannabinoids found in cannabis was placed in Schedule 4 as a ‘Prescription Only Medicine OR Prescription Animal Remedy’. Previous to this it was captured in Schedule 9 as a prohibited substance. [98]

New Zealand: CBD is a controlled drug. However, by passing the Misuse of Drugs Amendment Regulations 2017 in September 2017, many of the restrictions currently imposed by the regulations are removed since then. The changes will mean that CBD products, where the level of other naturally occurring cannabinoids is less than 2% of the cannabinoid content, will be easier to access for medical use. [99]

Switzerland: CBD is not subject to the Narcotics Act because it does not produce a psychoactive effect. It is still subject to standard Swiss legislation. [100]

Also see Annex 1: Report on WHO questionnaire for review of psychoactive substances.

19. Other Medical and Scientific Matters Relevant for a Recommendation

on the Scheduling of the Substance None

https://www.gov.uk/government/organisations/medicines-and-healthcare-products-regulatory-agency



23

References

1. NCBI. PubChem Compound Database; CID=26346 August 1 2017]; Available from: https://pubchem.ncbi.nlm.nih.gov/compound/26346

2. Cayman Chemical. Cannabidiol (DEA Schedule I Regulated Compound). Safety Data Sheet 2015; Available from: https://www.caymanchem.com/msdss/90080m.pdf.

3. WHO Expert Committee on Drug Dependence : thirty-eighth report. Geneva: World Health Organization; 2017 (WHO technical report series ; no. 1005). Licence: CC BY-NC-SA 3.0 IGO.

4. Shah, V.J., Synthesis of cannabidiol stereoisomers and analogs as potential anticonvulsant agents. The University of Arizona.

5. Bisogno, T., et al., Molecular targets for cannabidiol and its synthetic analogues: effect on vanilloid VR1 receptors and on the cellular uptake and enzymatic hydrolysis of anandamide. British Journal of Pharmacology, 2001. 134(4): p. 845-852.

6. Leite, J., et al., Anticonvulsant Effects of the (–) and (+)Isomers of Cannabidiol and Their Dimethylheptyl Homologs. Vol. 24. 1982. 141-6.

7. Petrzilka, T., W. Haefliger, and C. Sikemeier, Synthese von Haschisch-Inhaltsstoffen. 4. Mitteilung. Helvetica Chimica Acta, 1969. 52(4): p. 1102-1134.

8. Baek, S.-H., M. Srebnik, and R. Mechoulam, Boron triflouride etherate on alimina - a modified Lewis acid reagent. An improved synthesis of cannabidiol. Vol. 26. 1985. 1083–1086.

9. Mechoulam, R. and L. Hanus, Cannabidiol: an overview of some chemical and pharmacological aspects. Part I: chemical aspects. Chem Phys Lipids, 2002. 121(1- 2): p. 35-43.

10. Marks, M.D., et al., Identification of candidate genes affecting Δ(9)- tetrahydrocannabinol biosynthesis in Cannabis sativa. Journal of Experimental Botany, 2009. 60(13): p. 3715-3726.

11. Taura, F., et al., Cannabidiolic-acid synthase, the chemotype-determining enzyme in the fiber-type Cannabis sativa. FEBS Letters, 2007. 581(16): p. 2929-2934.

12. Russo, E.B., Cannabidiol Claims and Misconceptions. Trends in pharmacological sciences, 2017. 38(3): p. 198-201.

13. Sikora, V., et al., Influence of agroclimatic conditions on content of main cannabinoids in industrial hemp (Cannabis sativa L.). Vol. 43. 2011.

14. Tocris Bioscience. https://www.tocris.com/products/minus-cannabidiol_1570#product- details.

15. Aman, T., A. Rashid, and I. Khokhar, Spectrophotometric Determination of Cannabidiol. Analytical Letters, 1993. 26(10): p. 2113-2125.

16. Schwope, D.M., K.B. Scheidweiler, and M.A. Huestis, Direct quantification of cannabinoids and cannabinoid glucuronides in whole blood by liquid chromatography–tandem mass spectrometry. Analytical and Bioanalytical Chemistry, 2011. 401(4): p. 1273.

17. Sorensen, L.K. and J.B. Hasselstrom, Sensitive Determination of Cannabinoids in Whole Blood by LC-MS-MS After Rapid Removal of Phospholipids by Filtration. J Anal Toxicol, 2017. 41(5): p. 382-391.

18. Salomone, A., et al., Simultaneous analysis of several synthetic cannabinoids, THC, CBD and CBN, in hair by ultra-high performance liquid chromatography tandem mass spectrometry. Method validation and application to real samples. J Mass Spectrom, 2012. 47(5): p. 604-10.

19. Wei, B., L. Wang, and B.C. Blount, Analysis of Cannabinoids and Their Metabolites in Human Urine. Anal Chem, 2015. 87(20): p. 10183-7.

20. Aizpurua-Olaizola, O., et al., Simultaneous quantification of major cannabinoids and metabolites in human urine and plasma by HPLC-MS/MS and enzyme-alkaline hydrolysis. Drug Test Anal, 2017. 9(4): p. 626-633.

https://pubchem.ncbi.nlm.nih.gov/compound/26346

https://www.caymanchem.com/msdss/90080m.pdf

https://www.tocris.com/products/minus-cannabidiol_1570#product-details



24

21. Cirimele, V., et al., Testing human hair for Cannabis. III. rapid screening procedure for the simultaneous identification of delta 9-tetrahydrocannabinol, cannabinol, and cannabidiol. J Anal Toxicol, 1996. 20(1): p. 13-6.

22. Kim, J.Y., et al., Simultaneous determination of cannabidiol, cannabinol, and delta9- tetrahydrocannabinol in human hair by gas chromatography-mass spectrometry. Arch Pharm Res, 2005. 28(9): p. 1086-91.

23. Moore, C., S. Rana, and C. Coulter, Simultaneous identification of 2-carboxy- tetrahydrocannabinol, tetrahydrocannabinol, cannabinol and cannabidiol in oral fluid. J Chromatogr B Analyt Technol Biomed Life Sci, 2007. 852(1-2): p. 459-64.

24. Andrenyak, D.M., et al., Determination of -9-Tetrahydrocannabinol (THC), 11- hydroxy-THC, 11-nor-9-carboxy-THC and Cannabidiol in Human Plasma using Gas Chromatography-Tandem Mass Spectrometry. J Anal Toxicol, 2017. 41(4): p. 277

25. Milman, G., et al., Cannabinoids and Metabolites in Expectorated Oral Fluid Following Controlled Smoked Cannabis. Clinica Chimica Acta; International Journal of Clinical Chemistry, 2012. 413(7-8): p. 765-770.

26. Karschner, E.L., et al., Validation of a Two-Dimensional Gas Chromatography Mass Spectrometry Method for the Simultaneous Quantification of Cannabidiol, Δ(9)- Tetrahydrocannabinol (THC), 11-Hydroxy-THC and 11-nor-9-Carboxy-THC in Plasma. Analytical and bioanalytical chemistry, 2010. 397(2): p. 603-611.

27. Andrews, R. and S. Paterson, A validated method for the analysis of cannabinoids in post-mortem blood using liquid-liquid extraction and two-dimensional gas chromatography-mass spectrometry. Forensic Sci Int, 2012. 222(1-3): p. 111-7.

28. Gaoni, Y. and R. Mechoulam, Hashish-VII. The isomerization of cannabidiol to tetrahydrocannabinols. Vol. 22. 1966. 1481–1488.

29. Webster, G.R., L. Sarna, and R. Mechoulam, Conversion of cbd to delta8-thc and delta9-thc. 2004, Google Patents.

30. Watanabe, K., et al., Conversion of cannabidiol to Δ9-tetrahydrocannabinol and related cannabinoids in artificial gastric juice, and their pharmacological effects in mice. Forensic Toxicology, 2007. 25(1): p. 16-21.

31. Merrick, J., et al., Identification of psychoactive degradants of cannabidiol in simulated gastric and physiological fluid. Cannabis and Cannabinoid Research, 2016. 1(1): p. 102-112.

32. Bonn-Miller, M.O., S.L. Banks, and T. Sebree, Conversion of Cannabidiol Following Oral Administration: Authors' Response to Grotenhermen et al. DOI: 10.1089/can. 2016.0036. Cannabis and Cannabinoid Research, 2017. 2(1): p. 5-7

33. Wray, L., C. Stott, N. Jones, and S. Wright, Cannabidiol Does Not Convert to Δ9- Tetrahydrocannabinol in an In Vivo Animal Model. Cannabis and Cannabinoid Research, 2017. 2(1): p. 282-287.

34. Martin-Santos, R., et al., Acute effects of a single, oral dose of d9- tetrahydrocannabinol (THC) and cannabidiol (CBD) administration in healthy volunteers. Curr Pharm Des, 2012. 18(32): p. 4966-79.

35. Consroe, P., et al., Controlled clinical trial of cannabidiol in Huntington's disease. Pharmacology Biochemistry and Behavior, 1991. 40(3): p. 701-708.

36. Grotenhermen, F., E. Russo, and A.W. Zuardi, Even High Doses of Oral Cannabidol Do Not Cause THC-Like Effects in Humans: Comment on Merrick et al. Cannabis and Cannabinoid Research 2016;1(1):102–112; DOI: 10.1089/can.2015.0004. Cannabis and Cannabinoid Research, 2017. 2(1): p. 1-4.

37. Consroe, P., et al., Interaction of cannabidiol and alcohol in humans. Psychopharmacology, 1979. 66(1): p. 45-50.

38. Nahler, G., et al., A Conversion of Oral Cannabidiol to Delta9-Tetrahydrocannabinol Seems Not to Occur in Humans. Cannabis and Cannabinoid Research, 2017. 2(1): p. 81-86

39. Fasinu, P.S., et al., Current Status and Prospects for Cannabidiol Preparations as

25

New Therapeutic Agents. Pharmacotherapy, 2016. 36(7): p. 781-96. 40. Hawksworth, G. and K. McArdle, Metabolism and pharmacokinetics of cannabinoids.

The Medicinal Uses of Cannabis and Cannabinoids. Pharmaceutical Press, London, 2004: p. 205-228.

41. Devinsky, O., et al., Randomized, dose-ranging safety trial of cannabidiol in Dravet syndrome. Neurology, 2018. 90(14): p. e1204-e1211.

42. Ohlsson, A., et al., Single-dose kinetics of deuterium-labelled cannabidiol in man after smoking and intravenous administration. Biological Mass Spectrometry, 1986. 13(2): p. 77-83.

43. Jiang, R., et al., Identification of cytochrome P450 enzymes responsible for metabolism of cannabidiol by human liver microsomes. Life Sci, 2011. 89(5-6): p. 165-70.

44. McPartland, J.M., et al., Are cannabidiol and Δ9-tetrahydrocannabivarin negative modulators of the endocannabinoid system? A systematic review. British Journal of Pharmacology, 2015. 172(3): p. 737-753.

45. Pertwee, R., The diverse CB1 and CB2 receptor pharmacology of three plant cannabinoids: Δ9‐tetrahydrocannabinol, cannabidiol and Δ9‐ tetrahydrocannabivarin. British journal of pharmacology, 2008. 153(2): p. 199-215.

46. Long, L.E., et al., A behavioural comparison of acute and chronic Δ9- tetrahydrocannabinol and cannabidiol in C57BL/6JArc mice. International Journal of Neuropsychopharmacology, 2010. 13(7): p. 861-876.

47. Batalla, A., et al., Neuroimaging studies of acute effects of THC and CBD in humans and animals: a systematic review. Current pharmaceutical design, 2014. 20(13): p. 2168-2185.

48. Sultan, S.R., et al., A systematic review and meta-analysis of the haemodynamic effects of Cannabidiol. Frontiers in pharmacology, 2017. 8.

49. Laprairie, R., et al., Cannabidiol is a negative allosteric modulator of the cannabinoid CB1 receptor. British journal of pharmacology, 2015. 172(20): p. 4790-4805.

50. Martínez-Pinilla, E. et al., Binding and signaling studies disclose a potential allosteric site for cannabidiol in cannabinoid CB2 receptors. Frontiers in Pharmacology, 2017. 8(744): p. 1-10.

51. Bih, C.I., et al., Molecular targets of cannabidiol in neurological disorders. Neurotherapeutics, 2015. 12(4): p. 699-730.

52. Machado Bergamaschi, M., et al., Safety and side effects of cannabidiol, a Cannabis sativa constituent. Current drug safety, 2011. 6(4): p. 237-249.

53. Iffland, K. and F. Grotenhermen, An Update on Safety and Side Effects of Cannabidiol: A Review of Clinical Data and Relevant Animal Studies. Cannabis and Cannabinoid Research, 2017. 2(1): p. 139-154.

54. Hayakawa, K., et al., Repeated treatment with cannabidiol but not Δ9- tetrahydrocannabinol has a neuroprotective effect without the development of tolerance. Neuropharmacology, 2007. 52(4): p. 1079-1087.

55. Katsidoni, V., I. Anagnostou, and G. Panagis, Cannabidiol inhibits the reward- facilitating effect of morphine: Involvement of 5-HT1A receptors in the dorsal raphe nucleus. Addiction Biology, 2013. 18(2): p. 286-296.

56. French, E.D., K. Dillon, and X. Wu, Cannabinoids excite dopamine neurons in the ventral tegmentum and substantia nigra. Neuroreport, 1997. 8(3): p. 649-652.

57. Vann, R.E., et al., Divergent effects of cannabidiol on the discriminative stimulus and place conditioning effects of Δ9-tetrahydrocannabinol. Drug and Alcohol Dependence, 2008. 94(1-3): p. 191-198

58. Klein, C., et al., Cannabidiol potentiates Δ 9-tetrahydrocannabinol (THC) behavioural effects and alters THC pharmacokinetics during acute and chronic treatment in adolescent rats. Psychopharmacology, 2011. 218(2): p. 443-457.

26

59. Jarbe, T.U.C., B.G. Henriksson, and G.C. Ohlin, Δ9-THC as a discriminative cue in pigeons: effects of Δ8-THC, CBD, and CBN. Archives Internationales de Pharmacodynamie et de Therapie, 1977. 228(1): p. 68-72.

60. Haney, M., et al., Oral Cannabidiol does not Alter the Subjective, Reinforcing or Cardiovascular Effects of Smoked Cannabis. Neuropsychopharmacology: official publication of the American College of Neuropsychopharmacology, 2016. 41(8): p. 1974-1982.

61. Babalonis, S., et al., Oral cannabidiol does not produce a signal for abuse liability in frequent marijuana smokers. Drug and alcohol dependence, 2017. 172: p. 9-13.

62. Do Val-da Silva, R.A., et al., Protective effects of cannabidiol against seizures and neuronal death in a rat model of mesial temporal lobe epilepsy. Frontiers in Pharmacology, 2017. 8.

63. Mechoulam, R. and E. Carlini, Toward drugs derived from cannabis. Naturwissenschaften, 1978. 65(4): p. 174-179.

64. Cunha, J.M., et al., Chronic administration of cannabidiol to healthy volunteers and epileptic patients. Pharmacology, 1980. 21(3): p. 175-185.

65. Ames, F. and S. Cridland, Anticonvulsant effect of cannabidiol. South African medical journal= Suid-Afrikaanse tydskrif vir geneeskunde, 1986. 69(1): p. 14-14.

66. Trumbly, B. Double-blind clinical study of cannabidiol as a secondary anticonvulsant. in Presented at Marijuana'90 Int. Conf. on Cannabis and Cannabinoids, Kolympari (Crete). 1990.

67. Devinsky, O., et al., Cannabidiol in patients with treatment-resistant epilepsy: an open-label interventional trial. The Lancet Neurology, 2016. 15(3): p. 270-278.

68. Devinsky, O., et al., Trial of Cannabidiol for Drug-Resistant Seizures in the Dravet Syndrome. New England Journal of Medicine, 2017. 376(21): p. 2011-2020.

69. Thiele, E.A., et al., Cannabidiol in patients with seizures associated with Lennox-Gastaut syndrome (GWPCARE4): a randomised, double-blind, placebo-controlled phase 3 trial. Lancet, 2018. 391(10125): p.1085-1096.

70. Geffrey, A.L., et al., Drug–drug interaction between clobazam and cannabidiol in children with refractory epilepsy. Epilepsia, 2015. 56(8): p. 1246-1251.

71. Devinsky, O., et al., Cannabidiol: Pharmacology and potential therapeutic role in epilepsy and other neuropsychiatric disorders. Epilepsia, 2014. 55(6): p. 791-802.

72. Pisanti, S., et al., Cannabidiol: State of the art and new challenges for therapeutic applications. Pharmacol Ther, 2017. 175: p. 133-150.

73. Yeshurun, M., et al., Cannabidiol for the prevention of Graft-versus-Host-Disease after allogeneic hematopoietic cell transplantation: Results of a Phase II study. Biol Blood Marrow Transplant, 2015. 21(10): p. 1770-5.

74. McGuire, P., et al., Cannabidiol (CBD) as an adjunctive therapy in schizophrenia: A multicenter randomized controlled trial. Am J Psychiatry, 2018. 175(3): p. 225-231.

75. Irving, P.M., et al., A randomized, double-blind, placebo-controlled, parallel-group, pilot study of cannabidiol-rich botanical extract in the symptomatic treatment of ulcerative colitis. Inflamm Bowel Dis, 2018. 24(4): p.714-724.

76. Cunetti, L., et al., Chronic pain treatment with cannabidiol in kidney transplant patients in Uruguay. Transplant Proc, 2018. 50(2): p. 461-464.

77. Hundal, H., et al., The effects of cannabidiol on persecutory ideation and anxiety in a high trait paranoid group. J Psychopharmacol, 2018. 32(3): p. 276-282.

78. Prud’homme, M., R. Cata, and D. Jutras-Aswad, Cannabidiol as an intervention for addictive behaviors: a systematic review of the evidence. Substance abuse: research and treatment, 2015. 9: p. 33.

79. World Health Organisation. WHO Model Lists of Essential Medicines. March 2017 21 August 2017]; Available from: http://www.who.int/medicines/publications/essentialmedicines/en/.

80. Echo Pharmaceuticals B.V. Improved uptake of cannabinoid based medicine. Available

http://www.who.int/medicines/publications/essentialmedicines/en/

27

from: http://www.echo-pharma.com/en/about-us/news/improved-uptake-of- cannabinoid-based-medicine

81. Zynerba® Pharmaceuticals. Available from: http://zynerba.com/. 82. Bionorica/THC Pharma. Available from: http://www.cannabidiol-

solutions.com/production-process/. 83. Morgan, C.J., et al., Cannabidiol reduces cigarette consumption in tobacco smokers:

preliminary findings. Addict Behav, 2013. 38(9): p. 2433-2436. 84. Arndt, D.L., and H. de Wit, Cannabidiol does not dampen responses to emotional stimuli

in healthy adults. Cannabis and Cannabinoid Research, 2017. 2(1): p.105-113. 85. Atsmon, J., et al., Single-dose pharmacokinetics of oral cannabidiol following

administration of PTL101: A new formulation based on gelatin matrix pellets technology. Clin Pharm Drug Dev, 2017. doi: 10.1002/cpdd.408.

86. Ananda Scientific. Available from: https://www.anandascientific.com/. 87. GW pharmaceuticals. GW Pharmaceuticals Receives FDA Fast Track and EMA

Orphan Designations for Intravenous Cannabidiol in the Treatment of Neonatal Hypoxic-Ischemic Encephalopathy (NHIE). 6 August 2015 11 August 2017]; Available from: https://www.gwpharm.com/about-us/news/gw-pharmaceuticals- receives-fda-fast-track-and-ema-orphan-designations-intravenous.

88. European Medicines Agency. EU/3/15/1520 orphan designation for cannabidiol for the treatment of perinatal asphyxia. 28 July 2015 10 August 2017]; Available from:http://www.ema.europa.eu/ema/index.jsp?curl=pages/medicines/human/orphans/2015/08/human_orphan_001612.jsp&mid=WC0b01ac058001d12b.

89. Mohammed, N., et al., Neuroprotective Effects of Cannabidiol in Hypoxic Ischemic Insult. The Therapeutic Window in Newborn Mice. CNS & Neurological Disorders -Drug Targets- CNS & Neurological Disorders), 2017. 16(1): p. 102-108.

90. Bonn-Miller, M.O., et al., Labeling accuracy of cannabidiol extracts sold online. JAMA, 2017. 318(17): p. 1708-1709.

91. U.S. Food and Drug Administration. Warning Letters and Test Results for Cannabidiol-Related Products. Available from: https://www.fda.gov/NewsEvents/PublicHealthFocus/ucm484109.htm.

92. GW pharmaceuticals. Sativex. 2016 10 August 2017]; Available from: https://www.gwpharm.com/products-pipeline/sativex

93. Medical Marijuana Inc. What is cannabidiol? 11 October 2016 20 August 2018]; Available from: http://www.medicalmarijuanainc.com/what-is-cannabidiol/.

94. Canabidol™ The Best Selling CBD Supplement in Europe. CBD cannabis oil. 20 August 2017]; Available from: https://canabidol.com/.

95. United Nations Office on Drugs and Crime. International Drug Control Conventions. [cited 21 August 2017; Available from: https://www.unodc.org/unodc/en/commissions/CND/conventions.html.

96. Medicines and Healthcare products Regulatory Agency. 1 August 2017]; Available from: https://www.gov.uk/government/news/mhra-statement-on-products-containing- cannabidiol-cbd

97. Government of Canada Justice Laws Website. 1 August 2017]; Available from: http://laws-lois.justice.gc.ca/eng/acts/c-38.8/FullText.html.

98. Australian Government Department of Health Therapeutic Goods Administration. 1August 2017]; Available from: https://www.tga.gov.au/book/part-final-decisions- matters-referred-expert-advisory-committee-2.

99. New Zealand Government Ministry of Health. 6 September 2017]; Available from: http://www.health.govt.nz/our-work/regulation-health-and-disability- system/medicines-control/medicinal-cannabis/cbd-products.

100. Swiss Agency for Therapeutic Products. 1 August 2017]; Available from: https://www.swissmedic.ch/aktuell/00673/03778/index.html?lang=en

http://www.echo-pharma.com/en/about-us/news/improved-uptake-of-cannabinoid-based-medicine



http://zynerba.com/

http://www.cannabidiol-solutions.com/production-process/

http://www.cannabidiol-solutions.com/production-process/

https://www.anandascientific.com/

https://www.gwpharm.com/about-us/news/gw-pharmaceuticals-receives-fda-fast-track-and-ema-orphan-designations-intravenous



https://www.fda.gov/NewsEvents/PublicHealthFocus/ucm484109.htm

https://www.gwpharm.com/products-pipeline/sativex

http://www.medicalmarijuanainc.com/what-is-cannabidiol/

https://canabidol.com/

https://www.unodc.org/unodc/en/commissions/CND/conventions.html

https://www.gov.uk/government/news/mhra-statement-on-products-containing-cannabidiol-cbd



http://laws-lois.justice.gc.ca/eng/acts/c-38.8/FullText.html

https://www.tga.gov.au/book/part-final-decisions-matters-referred-expert-advisory-committee-2



http://www.health.govt.nz/our-work/regulation-health-and-disability-system/medicines-control/cannabidiol



Exhibit G

Key pharmacological differences between side effects of refined, pharmaceutical CBD formulations and whole plant extracts

By: James Holley, Molecular Biologist, Scientific Officer, Mike Robinson, Co-founder, Research Institute, and Dr. David Ostrow, M.D., Research Director

International Cannabinoid Cancer Research Institute (Draft 5) Estimated Date Nov 2018. https://is.gd/dzrPf2

With review by: (Pending) (This is not the Final Draft)

Abstract: (This is not the final draft, the final is being submitted for Journal Publications)

Recent studies on the effectiveness of cannabidiol in the rare seizure disorders Dravet Syndrome and Lennox-Gastaut syndrome have prompted a biopharmaceutical company to perform clinical trials of its own to bring a cannabidiol based drug to the American market through the process of FDA approval. Side effects were very prevalent in 79% of all patients taking a refined CBD product, some of which were severe like thrombocytopenia and transaminase elevations in the liver. However, there are indications from studies done with cannabidiol-rich cannabis extracts in Israel that indicate that less side effects (46%) are achieved with a natural cannabis plant extract containing a 20:1 ratio of CBD to THC. This paper seeks to answer why refined cannabinoids have more side effects than the natural cannabis product, as well as the possible etiology of said adverse reactions. Also discussed are other attempts at affecting the cannabinoid system from a singular standpoint. Ultimately, the cannabinoid system works by way of multiple molecules affecting multiple receptors at once – the entourage effect, and thus such singular approaches to treatment by way of the cannabinoid system are not effective. Traditional plant extracts contain many compounds in addition to THC and CBD that contribute to the medical benefits of cannabis.

Introduction:

Recently, a formulation of cannabidiol was approved by the United States FDA. It is extracted from hemp grown using conventional agricultural methods like pesticides and fertilizers and extracted using supercritical carbon dioxide, crystallized, and put into a formulation with sesame oil, strawberry flavoring, alcohol, and sucralose, to be used alongside existing anti-seizure medications like clobazam. This differs sharply from the conventional course of cannabis medicine, which is to use whole, clean plant extracts to treat epilepsy and to gradually discontinue use of conventional pharmaceuticals. The question is, is there truly a difference? It might be argued by some that a compound is a compound, carbon for carbon, and thus it would have the same effects. However, it is sometimes the case that the pill binder or other carrier causes a medication issue. A review of the research must be done to find if natural plant extracts have an advantage over synthetic delivery systems.

Review:

During an open-label trial of pure CBD with Lennox-Gastaut and Dravet patients, 79% of all patients reported side effects. The most common side effects reported were somnolence (25%), decreased appetite (19%) diarrhea, (19%) Fatigue, (13%) Elevated liver enzymes, (7%) Convulsion, (11%) Increased appetite, (9%) Status epilepticus, (8%) Lethargy, (7%) Weight increased, (7%) Weight decreased, (6%) Drug concentration increased, (6%). Serious side effects in 30% of patients included status epilepticus in 6%, severe hepatotoxicity in 1 patient, and hyperammonemia in another. One patient died but it was ruled to be part of the course of their disorder and not a drug effect. The liver and urea cycle side effects were related to co-intake of valproate, the pre-existing medication. (1) The official FDA side effects include insomnia (11%) irritability (9%), a chance of suicidal ideation “common to anticonvulsants” and

� of �1 7

https://is.gd/dzrPf2


a 33% higher chance of infection. It makes no mention of any interaction with valproate (2) CBD was also found to increase the active metabolite of clobazam, a common medication for refractory epilepsy, by blocking cytochrome p450 enzymes CYP2c19 and 3A4. (3) All side effects were for a 70% overall seizure reduction and 52% reporting a decrease of 50% or more.

An Israeli study of cannabis versus epilepsy, however, used natural extracts with a ratio of 20:1 CBD:THC. When administered to children with epilepsy, seizure reduction occurred in 89% of patients and 54% achieved over 50% reduction. Only 7% had an increase in seizures, and only 7% had restlessness and irritability. 34/74 patients in all had side effects, or 46%. (4) Interestingly enough, Aran noted a similar prevalence of irritability and restlessness in the Israeli CBD trial for autism, further underlining the connections between autism and seizures. (5). In all of these trials, none of the patients were on other medications concurrently – it is common practice in cannabis medicine in both California and Israel to withdraw from other medication. No hepatic side effects were noted.

These two studies are not alone in their findings. A recent meta-analysis of CBD studies on Dravet, Lennox-Gastaut, and CDKL5, 5 of them using purified CBD and 6 of them using a CBD-rich extract, found more improvement in general with CBD-rich extracts. However, the number of patients experiencing a reduction of 50% or more held steady between the two groups at 39-42%. The CBD-rich extract group had a lower effective dose on average, 6.1 mg/kg while purified CBD required 27.1 mg/kg. Purified CBD also tripled the rate of both mild side effects such as appetite alteration, sleepiness, gastrointestinal disturbances/diarrhea, weight changes, fatigue, nausea, and severe side effects such as thrombocytopenia, respiratory infections, and alteration of liver enzymes. (6)

Discussion:

There are two possible explanations for the reduced side effect profile and increased efficacy of the whole plant extracts versus the refined CBD product now on the market. One of the main things that stands out is that in America, CBD was investigated as an adjunct to existing AEDs while in established cannabinoid medicine, patients are gradually withdrawn from existing drugs to use CBD. Drug interactions involving the liver are more common with multiple medications, and this is what was shown in the Lancet study. (1) Another is that the Israelis and others used whole plant extract with a small amount of THC in a 20:1 ratio. There is a phenomenon known as the “entourage effect” where the action of multiple cannabinoids and other plant compounds known as terpenes exhibit effects at a variety of receptors. This mimics what the endogenous cannabinoids do: they are synthesized at the same time in precise ratios, on demand, to exert precise effects on receptors. A neutral carrier made of sesame oil, strawberry flavoring, and sucralose has no synergy with CBD whatsoever. (7,8) Meanwhile, the terpene linalool has been shown to decrease glutamate binding and limonene and caryophyllene together have been shown to limit hippocampal excitability. (9,10)

Fig 1: Sucralose (In Study)

Fig 2: Ethyl Methylphenylglycidate (In Study)

Sucralose is common to use in a pediatric formulation. Although regarded as safe by the FDA, sucralose has since been find to alter glucose uptake and hormonal response to glucose, including of course insulin, and cause obesity in rats. (11) This effect is controversial in humans: some studies have shown no effect on glucose absorption in acute administration of sucralose in humans. (12) However, increased absorption of glucose was found, with corresponding increased insulin levels and decreased insulin sensitivity. (13) The strawberry flavoring ethyl methylphenylglycidate is another component with more questions than answers.

� of �2 7


It is registered as a pesticide ingredient with the EPA, and in the filing, LD50 numbers in rodents are noted and teratogenicity was noted in chickens. (14) NIH Toxnet cites studies that say that at 10000 ppm in rat feed caused growth retardation and testicular atrophy, while at 5000 ppm caused the demyelination of the sciatic nerve and can provoke hypersensitivity reactions with chronic exposure. (15) But more directly, there were two cases noted where strawberry flavoring caused reflex seizures with initial gamma band activity in the anterior inferior insula, with decreased activity in the hippocampus. (16) This is of interest because CB1 receptors are connected to gamma band activity and are most active in the hippocampus. (17,18) Meanwhile natural cannabinoids and terpenes are metabolized normally, with possible positive effects on blood sugar and metabolism and no added risk of seizures. (19)

Fig. 3. Synthesis of the synthetic cannabinoid JWH-018. (within study)

There have been other attempts to use a singular compound to affect the endocannabinoid system. For several years Dr. Piomelli at UC Irvine and his lab were involved in the development of FAAH inhibitors – substances that inhibited the breakdown of endocannabinoids. (20) The aim was to increase the level of 2-AG and anandamide in general so as to produce effective relief for a cannabinoid deficiency without any psychoactive side effects. Things seemed to go well in animal trials using URB597. (21) However, human trials of a similar compound BIA-10-2474 in France ended in disaster causing brain damage. (22) The problem in this case may have been off target inhibition of lipid metabolism in the brain, causing something similar to Tay-Sachs disease. (23) Piomelli predicted this might happen and he and other scientists disagree with how the French company went ahead with human trials. (24) Another famous attempt is the CB1 antagonist rimonabant – it was briefly tried as an appetite suppressant before it was found to cause anxiety, depression, and suicidal thoughts, causing Europe to ban the drug and major drug companies to stop researching the whole class of drug for human use. (25) Synthetic CB agonists, created to study the cannabinoid system, escaped the lab and became a whole new drug problem in the form of “Spice”. These chemicals have caused deaths and overdoses nationwide, causing New York to ban them on September 13, 2012 and the USA to follow suit, though new compounds are made every day. (26)

Fig. 4. THC

Another example of cannabinoid mono therapy is the THC pharmaceutical Marinol. After Professor Raphael Mechoulams discovery of THC as the main active principle in 1964, it took 22 more years for the FDA to approve its use as an appetite stimulant for AIDS and cancer patients, and only when all else had failed. (27) A 1998 study found a low potential for abuse and no indication of patients chasing the drug. (28) Side effects noted included strangely enough, vomiting and abdominal pain, psychiatric side effects including depression and paranoia, and low blood pressure. It has the same onset time of 60-90 min as cannabis edibles but only lasts 2-4 hours: many patients report edible cannabis made using the whole plant lasting 6-8 hours or more and find Marinol to be an inferior product (29,30). Concerns about mental and developmental health have been raised over THC and high THC cannabis concentrates, however CBD has been shown to moderate or even cancel out the effects of THC. (7). Hemp extracts are known to contain a small amount of THC even when derived from a CBD-rich cannabis cultivar and are known to produce positive test results for THC even in users of CBD hemp products. (31) The United States DEA has stated that small amounts of other cannabinoids will also occur in all cannabis extracts, even those that purport to be CBD only – unless synthesized de novo, CBD isolate will always contain small amounts of THC when extracted from a plant. Even chromatography is not perfect. If so, CBD medicines should warn of this at least for the purposes of drug testing. (32)

Fig. 5. CBD

� of �3 7


But how exactly does CBD by itself produce adverse effects in a small percentage of seizure and autism patients when it is well tolerated by 90% of the patient population? Even whole plant extracts are not tolerated by this group. This is where emerging science may provide an answer. CBD is mostly antagonistic towards the CB1 and CB2 receptors, with a Ki of 3500-4000 nanomolar. (33) It has been found to be a negative allosteric modulator of both of them. (34, 35) It is also an antagonist at GPR55 and 18 which have been shown to be secondary cannabinoid receptors (36,37). THC, for example, is a full agonist at GPR18. (38). Mutations in MBOAT7, which produces the natural ligand lycophosphatidylinositol for GPR55, are linked to autism. (39) A duplication of the region containing GPR18 was linked to another case. (40) It is thus possible that autism and seizure cases exist where the proper rescue pathway is through stimulation of the GPR receptors and not via the multiple, mostly antagonistic actions that CBD is known for. CBD and other cannabinoids are also known for having a bell-shaped dose-response curve. In an experiment with mice using CBD-rich extract, the anti-inflammatory and pain relief effects peaked at only 5 mg/kg, which is close to the average dose found in CBD-rich extract studies. However, use of whole plant extract was able to overcome this and make the relationship correlative. It is possible that the dose used in studies using isolated CBD is too high in general and given the prospective study design in those studies versus the retrospective design used in the extract studies this remains a possibility. (41,6)

Conclusion:

Ultimately cannabinoid medicine must be based on a sound understanding of the underlying biological systems involved, as well as the unique human physiological response to inert synthetic ingredients that are proven herein to be the causation of most, if not all the side effects listed by the F.D.A. on the new pharmaceutical, and that the vast majority of these side effects are not from any extract of Cannabis, including CBD. As well, the conventional approach of isolating a single active principle and using it when prior study does not support such applications within the Endocannabinoid System, where multiple components are manufactured by the same enzymes in ratios to exert an effect in concert on the system in whole. More research is needed to determine proper ratios for specific conditions, as well as genetic testing developed to determine appropriate course of treatment. In all, neither CBD or THC alone are as opportune as a mono therapy without other accompanying elements of the plant including phytocannabinoids and terpenes. Efficacy in study is reduced when one cannabinoid is isolated away from the balance of the cannabis plant. The side effects stemming from the addition of synthetic inert ingredient to sweeten and flavor are found to be a risk of consideration for further study. When combined with other pharmaceutical medications, specifically seizure medications, the side effects are unnecessary and again, in a large part a cause of inert ingredients. In conclusion, the removal of Cannabidiol from its accompanying plant terpenes and other cannabinoids and it’s placement into a carrier consisting of sucralose, a synthetic strawberry flavoring, and sesame oil also reduces the effectiveness and heavily contributes to the F.D.A. listed common and severe side effects. There is no way to conclude that the new pharmaceutical compares to whole plant extract in any scientific way other than containing an isolated cannabinoid. Regarding the warning for specific populations that based on animal data the pharmaceutical may cause fetal harm. There is sufficient data, as indicated in discussion, that inert ingredients within this newly approved CBD pharmaceutical for the US Market have already been proven to cause harm in the unborn fetus, and not the cannabinoid. This would explain the special warning upon the current FDA approved drug. Moreover, since CBD can never be fully isolated, the packaging of CBD medicines should warn about the presence of THC.

References

� of �4 7


1. Orrin Devinsky*, Eric Marsh*, Daniel Friedman*, Elizabeth Thiele, Linda Laux, Joseph Sullivan, Ian Miller, Robert Flamini, Angus Wilfong, Francis Filloux, Matthew Wong, Nicole Tilton, Patricia Bruno, Judith Bluvstein, Julie Hedlund, Rebecca Kamens, Jane Maclean, Srishti Nangia, Nilika Shah Singhal, Carey A Wilson, Anup Patel, Maria Roberta Cilio. Cannabidiol in patients with treatment-resistant epilepsy: an open-label interventional trial. Lancet Neurol Dec 23 2015.2. FDA Epidiolex side effects warning sheet, revised3. 1Alexandra L. Geffrey, 1Sarah F. Pollack, Patricia L. Bruno, and Elizabeth A. Thiele. Drug–drug interaction between clobazam and cannabidiol in children with refractory epilepsy. Epilepsia, 56(8):1246–1251, 20154. Moran Hausman-Kedem MD and Uri Kramer MD. Efficacy of Medical Cannabis for Treating Refractory Epilepsy in Children and Adolescents, with Emphasis on the Israel Experience. IMAJ, FEBRUARY 20175. ADI ARAN, Hanoch Cassuto, Asael Lubotzky. Cannabidiol Based Medical Cannabis in Children with Autism- a Retrospective Feasibility Study. Neurology, April 10, 2018; 90 (15 Supplement)6. Fabricio A. Pamplona1*, Lorenzo Rolim da Silva2 and Ana Carolina Coan3Potential Clinical Benefits of CBD-Rich Cannabis Extracts Over Purified CBD in Treatment-Resistant Epilepsy: Observational DataMeta-analysis. Neurol. 9:759.7. W-SV Ho1, DA Barrett2 and MD Randall1. ‘Entourage’ effects of N-palmitoylethanolamide and N-oleoylethanolamide on vasorelaxation to anandamide occur through TRPV1 receptors. British Journal of Pharmacology (2008) 155, 837–8468. Ethan Russo. A tale of two cannabinoids: The therapeutic rationale for combining tetrahydrocannabinol and cannabidiol. Medical Hypotheses (18 aug 2005)9. Ahmad Abdulla 1 , Mahshid Hosseini-Zareh 1 , Jok?bas Žiburkus. Cannabis terpenes synergistically modulate hippocampal excitability. Department of Biology and Biochemistry, University of Houston, Houston, TX.10. Elisabetsky E1, Brum LF, Souza DO. Anticonvulsant properties of linalool in glutamate-related seizure models. Phytomedicine. 1999 May;6(2):107-13.11. Kimihiko Mitsutomi, Takayuki Masaki?, Takanobu Shimasaki, Koro Gotoh, Seiichi Chiba, Tetsuya Kakuma, Hirotaka Shibata. Effects of a nonnutritive sweetener on body adiposity and energy metabolism in mice with diet-induced obesity. METABOLISM CLINICAL AND EXPERIMENTAL 63 (2014) 69 – 7 812. Jing Ma1,2, Jessica Chang3 , Helen L. Checklin1,2, Richard L. Young1,2,4, Karen L. Jones1,2, Michael Horowitz1,2,3 and Christopher K. Rayner1 .Effect of the artificial sweetener, sucralose, on small intestinal glucose absorption in healthy human subjects. British Journal of Nutrition (2010), 104, 803–80613. YANINA PEPINO, PHD COURTNEY D. TIEMANN, MPH, MS, RD BRUCE W. PATTERSON, PHD BURTON M. WICE, PHD and SAMUEL KLEIN, MD. Sucralose Affects Glycemic and Hormonal Responses to an Oral Glucose Load. Diabetes Care. 2013 Sep;36(9):2530-514.http://pmep.cce.cornell.edu/pr...15.https://toxnet.nlm.nih.gov/cgi...16. Blauwblomme T, Kahane P, Minotti L, et al Multimodal imaging reveals the role of γ activity in eating-reflex seizures Journal of Neurology, Neurosurgery & Psychiatry 2011;82:1171-1173.17. Jose Cortes-Briones1,2, Patrick D Skosnik1,2,3, Daniel Mathalon2,4,5, John Cahill1,2,3, Brian Pittman2,3, Ashley Williams1,3, R Andrew Sewell1,2,3, Mohini Ranganathan1,2,3, Brian Roach4,5, Judith Ford2,4,5 and Deepak Cyril D’Souza*,1,2,3. Δ9-THC Disrupts Gamma (γ)-Band Neural Oscillations in Humans. Neuropsychopharmacology (2015) 40, 2124–213418. Davies SN1, Pertwee RG, Riedel G.Functions of cannabinoid receptors in the hippocampus.Neuropharmacology.. 2002 Jun;42(8):993-1007.19. Pablo Juan-Pico´ a, Esther Fuentes a, F. Javier Bermudez-Silva ´ b, F. Javier D´?az-Molina b, Cristina Ripoll a, Fernando Rodr´?guez de Fonseca, Angel Nadal Cannabinoid receptors regulate Ca2+ signals and insulin secretion in pancreatic #Beta cell. Cell Calcium 39 (2006) 155–162

� of �5 7


20. Darren Fegley, Silvana Gaetani, Andrea Duranti, Andrea Tontini, Marco Mor,Giorgio Tarzia, and Daniele PiomelliCharacterization of the Fatty Acid Amide Hydrolase Inhibitor Cyclohexyl Carbamic Acid 3 -Carbamoyl-biphenyl-3-yl Ester (URB597): Effects on Anandamide and Oleoylethanolamide Deactivation. JPET 313:352–358, 200521. Roberto Russo, Jesse LoVerme, Giovanna La Rana, Timothy R. Compton, Jeff Parrott, Andrea Duranti, Andrea Tontini, Marco Mor, Giorgio Tarzia, Antonio Calignano, and Daniele Piomelli The Fatty Acid Amide Hydrolase Inhibitor URB597 (Cyclohexylcarbamic Acid 3 -Carbamoylbiphenyl-3-yl Ester) Reduces Neuropathic Pain after Oral Administration in Mice. JPET 322:236–242, 200722. Christophe Mallet1,2, Claude Dubray1,2,3, and Christian Dualé1,3 FAAH inhibitors in the limelight, but regrettably. International Journal of Clinical Pharmacology and Therapeutics, Vol. 54 – No. 7/2016 (498-501)23. Annelot C. M. van Esbroeck,1 * Antonius P. A. Janssen,1 * Armand B. Cognetta III,2 et al. Activity-based protein profiling reveals off-target proteins of the FAAH inhibitor BIA 10-2474. Science 356, 1084–1087 (2017)24. New clues to why a French drug trial went horribly wrong. Science, June 201725. Bernard Le Foll, MD, PhD1, David A. Gorelick, MD, PhD2, and Steven R. Goldberg, PhD3. The future of endocannabinoid-oriented clinical research after CB1 antagonists. Psychopharmacology (Berl). 2009 July ; 205(1): 171–174.26: http://rules.cityofnewyork.us/...27: Gaoni and R. Mechoulam. Isolation, Structure, and Partial Synthesis of an Active Constituent of Hashish. Journal of the American Chemical Society 1964 86 (8), 1646-164728: Calhoun SR, Galloway GP, Smith DE . Abuse potential of dronabinol (Marinol)”. Journal of Psychoactive Drugs. 30 (2): 187–96.(1998)29: US Food and Drug Administration “Marinol (Dronabinol)” (PDF). September 2004.30: “Cannabis effects by Erowid” https://erowid.org/plants/cannabis/cannabis_effects.shtml31: Gero Leson et al. Evaluating the Impact of Hemp Food Consumption on Workplace Drug Tests. Journal of Analytical Toxicology, Vol. 25, November/December 200132: United States DEA. Establishment of a New Drug Code for Marihuana Extract.https://www.deadiversion.usdoj...33: RG Pertwee. The diverse CB1 and CB2 receptor pharmacology of three plant cannabinoids: D9 -tetrahydrocannabinol, cannabidiol and D9 -tetrahydrocannabivarin. British Journal of Pharmacology (2008) 153, 199–21534: R B Laprairie1 , A M Bagher1 , M E M Kelly1,2 and E M Denovan-Wright1. Cannabidiol is a negative allosteric modulator of the cannabinoid CB1 receptor. British Journal of Pharmacology (2015) 172 4790–480535: Eva Martínez-Pinilla1 * † , Katia Varani2† , Irene Reyes-Resina3,4† , Edgar Angelats3,4 , Fabrizio Vincenzi2 , Carlos Ferreiro-Vera5 , Julen Oyarzabal6 , Enric I. Canela3,4 , José L. Lanciego7 , Xavier Nadal5 , Gemma Navarro3,4,8 , Pier Andrea Borea2 and Rafael Franco. Binding and Signaling Studies Disclose a Potential Allosteric Site for Cannabidiol in Cannabinoid CB2 Receptors. Front. Pharmacol., 23 October 2017.36: McHugh, D., Hu, S. S., Rimmerman, N., Juknat, A., Vogel, Z., Walker, J. M., et al. (2010). N-arachidonoyl glycine, an abundant endogenous lipid, potently drives directed cellular migration through GPR18, the putative abnormal cannabidiol receptor. BMC Neurosci. 11:44.37: Ryberg, E., Larsson, N., Sjögren, S., Hjorth, S., Hermansson, N. O., Leonova, J., et al. (2007). The orphan receptor GPR55 is a novel cannabinoid receptor. Br. J. Pharmacol. 152, 1092–1101.38: Douglas McHugh1 , Jeremy Page1 , Emily Dunn1 and Heather B Bradshaw. D9 -Tetrahydrocannabinol and N-arachidonyl glycine are full agonists at GPR18 receptors and induce migration in human endometrial HEC-1B cells. British Journal of Pharmacology (2012) 165 2414–242439. Anide Johansen,1,2 Rasim O. Rosti,1 Damir Musaev,1 Evan Sticca,3 Ricardo Harripaul,4 Maha Zaki,5 Ahmet Okay C¸ aglayan,6 Matloob Azam,7 Tipu Sultan,8 Tawfiq Froukh,9 Andre´ Reis,10 Bernt Popp,10 Iltaf Ahmed,11 Peter John,11 Muhammad Ayub,12 Tawfeg Ben-Omran,

� of �6 7


13,14 John B. Vincent,4 Joseph G. Gleeson,1,3,15,* and Rami Abou Jamra10,16. Mutations in MBOAT7, Encoding Lysophosphatidylinositol Acyltransferase I, Lead to Intellectual Disability Accompanied by Epilepsy and Autistic Features. The American Journal of Human Genetics 99, 912–916, October 6, 2016.40. Atack a H. Fairtlough b K. Smith a M. Balasubramanian. A Novel (Paternally Inherited) Duplication 13q31.3q32.3 in a 12-Year-Old Patient with Facial Dysmorphism and Developmental Delay. Mol Syndromol 2014;5:245–250.41. Gallily, R., Yekhtin, Z. and Hanuš, L.O. (2015) Overcoming the Bell&dash;Shaped Dose&dash;Response of Can&dash; nabidiol by Using Cannabis Extract Enriched in Cannabidiol. Pharmacology & Pharmacy, 6, 75&dash;85.

-----------------------------------------------------------------------------------------------------

A Note from Mike: As a patient with severe epilepsy and a father of not one but two children with it? I will let the research and study we have done speak for itself for the most part, but I’ll be backing it with public appearances and interviews to head off the ‘side effect’ warnings that we WILL SEE on TV and hear on the radio. This is serious – CBD is under attack and by the use of a very disturbing way of creating a product for children. The topic of inert ingredients in CBD products has been ongoing since inception of the many different types of oils we see on the market. Never have I personally witnessed anything quite like this. My opinion on this all will come in a future blog, at this time we’re doing initial publishing as there are multiple entities, mostly Epilepsy Societies and Foundations, that are awaiting this document for analysis and publication.

Full Spectrum CBD products of the best type, many times will come from the same type of Cannabis flower or bud that the THC crowd loves. Genetics have allowed Cannabis to advance quickly.

There’s simply no excuse for bastardizing the plant in a manner we see here in the extremely factual and well planned research study above. Over 50 well known researchers globally weighed in, and many with varying opinions. But the facts that James and I initiated seemed to be the ones that most are paying attention to. Inert ingredients coupled with a single cannabinoid delivery created through an odd lab process create a product that fails to meet efficacy standards and meets all non standards of causing side effects that include increased seizures. This makes no sense unless the plot in releasing this drug that will only serve 1/2 of 1% of the world of Epilepsy was to once again marginalize cannabis by using already marginalized people like myself – those with Epilepsy. Those the world writes off for the most part anyway.

The inert ingredients within the newly approved Pharmaceutical CBD are not only in a large way responsible for key very concerning side effects within it, but are known to promote seizures in a big way – proven with studies on the exact same flavoring. Why would a pharmaceutical company do this? But it gets worse, these are carcinogens, and are blatantly unsafe in my strong professional opinion.

The fact that this ‘CBD only’ pharmaceutical can cause a positive THC test per the DEA rule 7350 yet has NO WARNING? Now that seems beyond dangerous to consumers – it’s downright irresponsible on both the pharmaceutical companies behalf and the FDA/DEA combo who seem to not read each others inter office memos.

� of �7 7

Exhibit H

A Phase 1, Open-Label, Parallel-Group, Single-Dose Trial of the Pharmacokinetics and Safety of Cannabidiol (CBD) in Subjects With Mild to Severe Hepatic ImpairmentLesley Taylor, Julie Crockett, Bola Tayo, Gilmour MorrisonJournal of Clinical Pharmacology 2019 March 28

The pharmacokinetics and safety of a single oral dose of 200-mg plant-derived pharmaceutical formulation of highly purified cannabidiol (CBD) in oral solution (Epidiolex in the United States; 100 mg/mL) were assessed in subjects with mild to severe hepatic impairment (n = 8 each for mild and moderate, n = 6 for severe) relative to matched subjects with normal hepatic function (n = 8). Blood samples were collected until 48 hours after dosing and evaluated by liquid chromatography and tandem mass spectrometry. Pharmacokinetic parameters (primarily maximum measured plasma concentration, area under the plasma concentration-time curve from time zero to time t, area under the concentration-time curve from time zero to infinity, time to maximum plasma concentration, and terminal half-life) of CBD and its major metabolites were derived using non-compartmental analysis. CBD was rapidly absorbed in all groups independent of hepatic function (median time to maximum plasma concentration, 2-2.8 hours). Exposure (area under the concentration-time curve from time zero to infinity) to total CBD slightly increased in subjects with mild hepatic impairment (geometric mean ratio [GMR], 1.48; 90% confidence interval [CI], 0.90-2.41). However, there were clinically relevant increases in subjects with moderate (GMR, 2.45; 90%CI, 1.50-4.01) and severe (GMR, 5.15; 90%CI, 2.94-9.00) hepatic impairment, relative to subjects with normal hepatic function. Exposure to the CBD metabolites (6-hydroxy-CBD and 7-hydroxy-CBD) also increased in subjects with moderate and severe hepatic impairment, but to a lesser extent than the parent drug. The 7-carboxy-CBD metabolite exposure was lower in subjects with severe hepatic impairment when compared with subjects with normal liver function. These findings indicate that dose modification is necessary in patients with moderate and severe hepatic impairment, and a lower starting dose and slower titration are necessary based on benefit-risk. CBD was well tolerated, and there were no serious adverse events reported during the trial.

Documents

comment?D=FDA-2019-N-1482-0001 07 16 HIA Public... · HIA, our advocacy partner the U.S. Hemp Roundtable, and many scholars and others disagree with the agency’s position. Section