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The Toxicology Laboratory's Role in Pain Management
Aut ho r: Kev in F. Fo ley , PhD , DABCC , MT, SC
Review e r: Rob e rt E. Mo o re, MLS(ASCP)C M
, SCC M
, TC (NRCC )
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Course Instructions
Please proceed through the course by clicking on the blue arrows or text links. Use the table of contents to monitor your
progress. Your progress will be saved automatically as you proceed through the course, and you may later continue where you
left off even if you use a different computer. You may encounter prac tice questions within the c ourse, which are not graded or
recorded.
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Course Info
This course carries the following continuing education credits:
l P.A.C .E. Contac t Hours: 2.00 hour(s)
Course Number: 578-018-13
l Florida Board of C linica l Laboratory Science C E - General (Clinical Chemistry/UA/ Toxicology): 2.00 hour(s)
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Laboratory Testing Methods For Drugs of Abuse
Course Introduction
Toxicology is the study of adverse effects of chemicals on living organisms. General toxicology is typica lly assoc iated with
environmental toxins and poisons such as ethylene glycol, heavy metals, pesticides, and carbon monoxide. However, drugs of
abuse (DOA) are usually considered part of the clinical toxicology laboratory's test menu as they are chemicals that have
adverse effects on humans.
This course will focus on DOA testing in the clinical laboratory and spec ifically in the context of pain management. DOA testing
in non-medica l settings, including employment testing and legal testing is not within the scope of this course.
Laboratory Testing Methods For Drugs of Abuse
Drugs of Abuse (DOA) Screening Tests
A DOA screen provides simple positive or negative results; it is
qualitative, not quantitative testing. DOA testing usually starts with ascreen and moves toward confirmation of spec ific d rugs, only if the
screen is positive.
Drug screening:
l Is fast
l Is qua litative, not quantitative
l Is generally performed on urine
l Can be done as a point-of-ca re (POC) test
l Often requires confirmatory testing for positive samples
A variety of devices are currently available from several manufacturers
for rapid urine DOA screening. Several examples are shown in the image
on the right.
Most laboratories will screen for at least the following DOA:
l Cocaine
l THC (Marijuana)
l Barbiturates
l Benzodiazepines
l Amphetamine and methamphetamine
l Opiates
l Oxycodone/oxymorphone
l Methadone
Some labs may also screen for tricyclic antidepressants, PCP, and propoxyphene.
Laboratory Testing Methods For Drugs of Abuse
Drugs of Abuse (DOA) Screening Tests, continued
A DOA screen can be done quickly using an immunoassay method. Immunoassays use antibodies direc ted against spec ific
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prototype chemical structures associated with specific drugs. They are ideal for screening since they can often pick up several
different drugs within the same class. For example, an immunoassay screen for benzodiazepines will likely pick up diazepam,
oxazepam, lorazapem, etc . All of these are benzodiazepines and so it is expected that the immunoassay will be positive in the
presence of any of them.
In general, screening tests like DOA immunoassays have adequate sensitivity but are not usually highly specific for a given drug. The
low specificity of DOA immunoassays, which is helpful for detecting the presence of any drug within the same class, is not helpful
when the screen is being used to detec t drugs used for pain management. An immunoassay c an tell you that a n opiate is present
but it cannot tell you which op iate is present. In pain management, it is not enough to know simply that a class of drugs was
detected. Rather, we need to know specifically which pa in drugs are present (ie, is it morphine, hydrocodone, etc.?)
Laboratory Testing Methods For Drugs of Abuse
Cutoff Concentrations for DOA Screening Tests
Drug screens use cutoff conc entrations to distinguish between negative and positive samples. For a qualitative test like a urine
drug screen it is important to consider that some arbitrary threshold has to be met for the assay to be positive. The c utoff po ints
for drugs of abuse on screening panels are usually determined by the immunoassay manufacturer. However, they can be
adjusted by the laboratory, if the laboratory prefers a higher or lower cutoff.
C linicians may over-interpret cutoffs and should be reminded that a negative result on a screening test does not necessarily
mean that the drug is not present in the sample, only that it is less than the c utoff conc entration established by the manufac turer o
laboratory for that drug. For example, if a sample screens negative for oxycodone, there may be oxycodone present in the sample,
but the c oncentration could be less than the laboratory's cutoff, eg, 100 ng/mL.
Cutoff concentrations should be posted with all laboratory screening results.
Below are some typical cutoff concentrations for DOA screens:
Laboratory Testing Methods For Drugs of Abuse
Confirmation of Positives
A confirmatory test is often ordered or reflexed when a positive drug screen is encountered, but not all positive DOA screens
need to be confirmed. For example, if a patient admits to using THC and the urine THC test is positive, the clinician can stop
there; there is no need to spend time and money confirming something that is not deemed suspicious. However, when a
screen gives an unexpected result or when we need to know which particular drugs are present, as in the c ase of pain
Drug Typical Cutoff Concentration
Amphetamine 500 ng/ mL
Barbiturates 200 ng/mL
THC 50 ng/mL
Cocaine/BE 300 ng/mL
Oxycodone/ Oxymorphone 100 ng/ mL
Opiates 300 ng/ mL
Methadone 300 ng/mL
Benzodiazepines 200 ng/mL
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management, confirmatory testing is necessary.
Confirmatory testing is always performed using gas chromatography and mass spectrometry (GC/MS) or liquid chromatography
with tandem mass spectrometry (LC-MS/MS). Unlike immunoassays, a GC-MS or LC-MS/MS instrument looks for specific chemica l
compounds. Mass spectrometry techniques can produce quantitative results, although not a ll laboratories report quantitative
results. In most cases, the clinician is only looking for the identity of the drug and not the quantity.
Laboratory Testing Methods For Drugs of Abuse
Mass Spectrometry (MS)
A thorough description of MS is
outside the scope of this course,
but a simple explanation may be
useful. To analyze specimens with
mass spectrometry, drugs first
need to be extrac ted from urine
samples using a series of organic
solvents. The elutions are theninjected into a chromatography
system. Chromatography refers to
a filtration type of process in
which samples are passed over a
stationary phase that contains
some chemical substrate, which
will retain molecules in the
sample in varying degrees. In the
case of gas chromatography-
mass spectrometry (GC-MS), the
sample is evaporated into a gas
and carried through a long thin
chromatography tube known as
the column. Different drugs in thesample will pass through the
column at different speeds,
depending on their affinity for the
column (how polar or non-polar
they are relative to the column's
stationary phase). There are many
different types of columns that
can be used to separate out compounds.
In liquid chromatography with tandem mass spectrometry (LC-MS/MS) methods the sample is carried by a solvent and through
a column that contains a gel-like liquid, which retains molecules in the samples in various degrees. The purpose of chromatography
is to get the molecules (in our case drugs) in the sample to come through the column one by one.
Imagine that you are asked to name a nd c ount all the different kinds of candy present in a giant bin containing many different
types and pieces of candy. It would be very hard to analyze all the different types of candy in the bin by just looking into the bin.But if we could get eac h piece of candy to pass by our eye one at a time, in single file, we could easily analyze and count eac h
piece. This is the purpose of the initial chromatography step; it allows a myriad of c ompounds to be injec ted but will retain
compounds in various degrees and they will (if the method is designed well), elute off the column and enter the MS instrument one
by one.
The drug molecules that are slowed or retained by the column will eventually continue through to the mass spectrometer. This
device fragments the molecule into charged ions. The ions are then pulled through a vacuum based on their charge. Their
trajec tory through the vacuum can be controlled using magnetic and radio frequency adjustments that will allow only ions of a
certain mass to hit the detec tor. The amount of ions that hit the detector is directly proportiona l to the amount of drug in the
sample. A technologist then must interpret, or at least review, the results from the instrument.
Chromatography with MS is highly specific and c an tell us which drugs are present and a t what concentrations. Labs can develop
and valida te methods that can detec t a given drug or metabolite with a specificity of >99.99%. The reason for this high degree of
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specificity is that a compound must have very specific qualities to be detected. If we a re looking for morphine, for example, we
know that our GC-MS instrument will only identify morphine if:
1. The c ompound has the exact retention time as morphine on our chromatography co lumn.
2. The compound fragments into the specific ions with the exact mass/charge found for morphine.
3. The ratios of those spec ific ion fragments to each other must match those found with morphine.
The odds that any drug other than morphine will meet these criteria is very low.
One disadvantage to MS methods is they are not highly automated.
Laboratory Testing Methods For Drugs of Abuse
False-Positive Opiate Results
Although confirmation methods should never produc e false-positive results,
the initial drug screens for opiates can sometimes be falsely positive. False-
positive results for opiate after ingestion of poppy seeds can occur with urine
drug screens. Poppy seeds contain the alkaloids morphine, and to a lesser
extent, codeine. Ingestion of foods with poppy seeds usually causes only
trac e (very low) amounts of morphine in the urine (usually less than 500
ng/mL). Quantitating opiates with mass spectroscopy is often useful to help
clinicians determine whether a positive opiate screen could have been due
to poppy seeds (a low amount is seen) or prescription opiates (which would
usually give higher concentrations). However there is no sure way to know,
and no rule to apply in order to determine definitively whether a positive
opiate result is due to poppy seeds or drug use.
Cough suppressants containing codeine and some quilolone drugs can also
cause false-positive opiate results with some brands of immunoa ssays. Since
many drugs of the opiate class can c ross-react in drug screens, confirmation
that an opiate is present and identification of the opiate that is present isimportant, espec ially for pa in management.
Laboratory Testing Methods For Drugs of Abuse
Laboratory Samples for DOA
One might initially think that serum would be the preferred sample for DOA testing. After all, serum is a highly-controlled,
homeostatic fluid that reflec ts the exac t metabolic state of the pa tient. Furthermore, it's easy to substitute or tamper with a
urine sample, since individuals being tested need to collect the urine themselves. It would be much harder to tamper with a
serum sample. So why don't we use serum for routine DOA testing?
The reason is that urine actually gives us a better window into the patient's history. Serum will contain trac es of any ingested
drugs but the liver and other tissues quickly clear the blood of drugs. Although each drug has a different half-life or kinetic in the
blood, most are c leared fairly rapidly, within hours.
Urine, on the other hand, tends to conc entrate drugs. This is due to the simple fact that urine is a small amount of volume
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compared to the total fluid in the body. As drugs are c leared by the kidneys, the urine bec omes more and more concentrated with
the drugs that were once present in the serum.
As an example, consider the opiate codeine. In the serum, an appropriate concentration of codeine would be around 13-35
ng/mL. However, due to the concentrating effec t of urine, we don't even c all a patient's urine positive for codeine until the
conc entration reac hes 150 ng/ mL. This is greater than 10-times more conc entrated than serum!
Other advantages to urine as samples for DOA testing are:
l The samples are read ily preserved by freezing.
l Drugs are stable in urine (Generally no c ells present to further metabolize the drugs).
l It is easier to obtain (although this also means it is easier to tamper with or adulterate).
Laboratory Testing Methods For Drugs of Abuse
Adulterants
In reference to urine testing for drugs of abuse
(DOA), adulteration of a sample means the
add ition of some agent (salts, ac ids, oxidizers or
even water) to one's urine sample to produc e a
falsely negative result. Adulteration is done to
trick the c linician into thinking the patient has no
drug use in the recent past.
Adulterants are simple chemical solutions that
change the pH of the urine, oxidize or reduc e
proteins, or change the ionic environment such
that the detection antibodies don't effectively
bind the drugs that are present or the chemicals
inac tivate the antibody-linked detection systems.
Some adulterants that are used include:
l Klear (KNO2)
l Whizzies (potassium nitrate)
l Urine Aid (glutaraldehyde)
l Synthetic urine
l Water dilution
Individuals have a lso added bleach, handsoap,
vinegar, or other common household items to
their sample to interfere with the screen. To combat adulteration of samples, laboratory professionals should be aware of
strange-smell or strange appearance of specimens. Ideally, the sample should be assessed by the collector within four minutes
so that normal color, odor, foaming, the presence of any prec ipitates, and the temperature can be checked. The temperature
should be between 90-100 F (32-38 C). The pH should be between 4-11. There are urine dipsticks ava ilab le, such as the exampleshown on the right, that test for the presenc e of adulterants. Some laboratories may choose to use these dipsticks to test pain
management urine samples.
The most important tests for adulteration are a simple urine creatinine and spec ific gravity. If the sample has a specific gravity of
less than 1.005 or the urine creatinine is less than 20 mg/ dL, adulteration of the sample should be suspected. Since it is so easy for a
patient to simply replace or dilute a specimen with tap water or toilet water, a c reatinine value
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Laboratory Testing Methods For Drugs of Abuse
Ungraded Practice Question
Adulteration of a urine sample collected for drugs of abuse testing refers to:
Plea se selec t the single b est answer
Laboratory Testing Methods For Drugs of Abuse
Ungraded Practice Question
Adulteration of a urine sample collected for drugs of abuse testing refers to:
nmlkjSubmitting another person's sample in place of your own.
nmlkj Adding something to the sample to cause interference and elicit a negative result.
nmlkj Concentrating one's sample to increase the chance of detecting a drug.
nmlkj Combining or using older samples over time to change the perceived time that someone took a drug.
Plea se selec t the single b est answer
Feedback
Adulteration of a sample for drugs of abuse testing refers to the add ition of some agent (salts, ac ids, oxidizers or even wa ter) to
one's urine sample in order to obtain a falsely negative result. Adulteration is done to trick the clinician into thinking the patient has
no drug use in the recent past.
The Use of Opiates For Pain Management and the Problem of Drug Abuse
Pain Management Contracts
When patients see a clinician to manage their pain they are, by
simple definition, pain management patients. The prac tice of pa in
mana gement is more involved than simply prescribing analgesics.
We will discuss the goals of pain management in coming sections.
The concept of a "pa in management contrac t," or an "opiate
therapy plan" is important to mention. When a patient's pain is
going to be managed with opiates or other prescription
ana lgesics the patient and clinician must agree to the terms of this
treatment.
nmlkj Submitting another person's sample in place of your own.
nmlkj Adding something to the sample to cause interference and elicit a negative result.
nmlkj Concentrating one's sample to increase the chance of detecting a drug.
nmlkj Combining or using older samples over time to change the perceived time that someone took a drug.
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Opiates are narcotics. A narcotic can refer to any drug derived
from op ium or opium-like c ompounds. These drugs have potent
analgesic effects and can cause alterations in mood and
behavior. Narcotics also have the potential for dependence and
tolerance with repeated administrations. Since these are strong
drugs, an agreement is usually signed between the clinician and
patient. This agreement, or contrac t has these provisions:
l Patient will not seek medica tions from other providers
l Patient will only use med ications that a re provided to
him/her
l Patient will not sell or give his/her medications to others
These contrac ts are important to establish trust and expectations
between the c linician and the patient. These c ontrac ts will often
also specify the requirements for routine urine drug testing.
The Use of Opiates For Pain Management and the Problem of Drug Abuse
Opiates
Opiates define a large c lass of drugs with structural similarity to morphine (a
major analgesic found in opium extrac t from the poppy flower). The term opioid
is often used interchangeably with the term opiate. However, the term op ia te
more properly refers to the na tural narcotic c ompounds (alkaloids) found in the
resin of the opium poppy (Pap ave r som niferum). Use of the term "opioid" shouldbe reserved for semi-synthetic substances that are derived from the opium poppy
or made completely in the lab. Opiates/opioids include the following drugs:
l Morphine: Contin, Oramorph, Roxanol
l Oxycodone: Oxycontin, Percoset
l Hydrocodone: Codan, Hycodan, Hydromet
l Hydromorphone: Dilaudid
l Loperamide: Imodium
l Methadone: Dolophin
Opiates activate opiate receptors found in the central nervous system (CNS). The
endogenous ligands for these receptors are endorphins and endorphin-likepeptides. Interestingly, opiates do not alter the pain threshold of nerve endings
nor do they affect the conductance of nerve impulses (like anesthetics do).
Instead, analgesia is mediated through c hanges in the perception of pain at the
spinal cord and higher levels in the CNS. There is no ceiling effect of analgesia for
opiates. The emotional response to pa in is also a ltered with opiate use. Opiates
are often referred to as euphoric medications since they can elevate mood. They also c an induce physical and emotional
dependence and addiction.
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The Use of Opiates For Pain Management and the Problem of Drug Abuse
Opiates, continued
Opiates/opioids are used predominantly for pain. However
opiates such as codeine c an be used as antitussives (to reduce
coughing). A well-known effect of opiates is that they decrease
GI motility. Opiate-induced constipation is a c ommon side effec t
of opiates. This side effec t is exploited in the drug loperimide(sold as Imodium). Loperimide is used to treat diarrhea. However
loperimide does not c ross into the brain so it does not have
abuse potential.
Opiates are Schedule 2 drugs, meaning they require a
prescription and have abuse potential. C linical uses for opiates
include:
l diarrhea
l migraine
l moderate pa in
l myalgia
l severe pain
l antitussives
Many newer analogs of morphine have been created that have
increased potency (such as sufentanil and fentanyl). Many opiates undergo metabolism to compounds that a lso have
significant activity. For example, the drugs codeine and heroin, which have effects at opiate receptors, both get metabolized
to morphine, which is also an ac tive compound (see figure).
Opiates can cause:
l miosis (pinpoint pupils) and thus blurred vision
l confusion
l constipation
l drowsiness
l euphoria
l
hypotensionl nausea/vomiting
l physiological dependence / tolerance
l respiratory depression
l syncope
The Use of Opiates For Pain Management and the Problem of Drug Abuse
Opiate Abuse
Although opiates are prescribed for pain they are
also used illicitly. Opiates can cause euphoria.
This trait means that opiates have value on the
street. Prescription opiate abuse is a tremendous
problem in the United States and other countries.
Abuse of non-prescription opiates centers around
the use of heroin. Heroin is simply morphine with
two additional acetyl-groups. Heroin is a very
potent opiate that is taken intravenously and
causes intense euphoria and narcosis.
When heroin is metabolized in the body it will
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initially lose one ac etyl group. The resulting
compound is 6-acetyl-morphine (abbreviated 6-
AM). The finding of 6-AM is conc lusive for heroin
use. However 6-AM is rapidly cleared so it is often
detected only in those who have used heroin in
the last few hours.
Immunoassays for codeine, morphine, and 6-
acetyl-morphine are commonly used in acute
care settings, emergency settings, and pain
management settings.
The Use of Opiates For Pain Management and the Problem of Drug Abuse
Other Drugs of Interest
Before we delve into the issues and concerns of pain management we should mention some other drugs encountered in
patients being screened for DOA. A lthough pain management usually involves opiates, there are a few other drugs that may
be used and could be detec ted by the toxicology laboratory. These include; suboxone (buprenorphrine), fentanyl, tramadol
and THC.
Buprenorphine is a semi-synthetic opioid that is commonly used to treat opiate addiction. It is often given a s a 2-drug
preparation containing buprenorphine plus naloxone. This is sold under the trade name Suboxone. Buprenorphine is a mixed
agonist/antagonist at the opiate receptor. Because of this, buprenorphine blocks the ac tivity of other opiates and induces
withdrawa l in opiate-dependent individuals who a re currently physically dependent on another opiate. Buprenorphine or Suboxone
is given to patients to help wean them from their opiate dependence. In this way it is used very much like methadone.
Buprenorphine is not detected by routine opiate screens.
Fentanyl is a synthetic opioid, which has become popular in recent years. It is commonly prescribed as a transdermal patch. In this
formulation it can provide c hronic pa in relief. Because it is a patch, oral ingestion is not possible (or at least not pa latable), and so
abuse is less likely. The important point concerning fentanyl is that it will not be detected by opiate screens since its structure is
significantly different from morphine analogs. It is also present in very low conc entrations. Specific assays for fentanyl are needed to
detec t this drug. Immunoassays for fentanyl are available.
Tramadol is a very weak activator of the opioid receptor. Its main mechanism of action seems to have more to do with serotonin
release and the inhibition of norepinephrine reuptake in the brain. However, metabolites of tramadol are more potent agonists of
opioid receptors. Tramadol has some abuse potential but is less euphoric than opiates like morphine. Its use in pain management is
increasing.
THC:Marijuana is used medica lly by many patients since many states now have laws that permit its use in certain circumstanc es.
The ac tion of THC is more of a relaxant than a true analgesic. Most clinicians who are treating pa in will ask their pa tients to not use
THC if they are being prescribed an opiate; the choice is usually to use one or the other but not both. The use of THC in pain
management patients is not common. However finding THC in the urine of patients undergoing pa in management is common.
Methadoneis a synthetic opioid with a long duration of action. It is used to help wean patients from opiate dependency.
The Use of Opiates For Pain Management and the Problem of Drug Abuse
Pain Management: The Problem
Drug abuse, and specifically prescription drug
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abuse, in the United States is a huge problem.
Consider the following fac ts taken from the US
Drug Enforcement Agency's website:
l 7 million Americans are abusing
prescription drugs (thats more than
cocaine, heroin, hallucinogens, ecstasy,
and inhalants, combined).
l Prescription drug abuse increased 80% in
the past 6 years.
l Opioid pa inkillers now c ause more drugoverdose deaths than cocaine and heroin
combined.
l Hydrocodone is the most commonly
diverted and abused controlled
pharmaceutical in the United States
l The Centers for Disease Control and
Prevention (CDC) estimates 20,000 people
die eac h year from prescription drug
overdose (74% from opiates)
l Opiate overdoses lead to 475,000
emergency department (ED) visits per year
Quest Diagnostics published a report in 2012 conc erning prescription drugs found in urine. The study looked at 76,000 drug tests and
found that 63% of all samples tested were not consistent with the physicians documented prescriptions. In 40% of cases, no drugwas detected where one was expec ted.
The Use of Opiates For Pain Management and the Problem of Drug Abuse
The Problem, continued
The Quest study verified what people involved in DOA testing already knew: patients are not always compliant and drug
testing is needed to help detect diversion and abuse.
Diversion refers to the absence of a drug in a patient's sample because their prescribed drug was diverted to someone else
(sold or given away). Diversion of a prescribed drug is just as serious as detecting an unprescribed drug. The Quest study
showed that patients who were tested 30 days after an initial finding had 10% fewer unexpected findings. For pain medication,
a 17% reduc tion was found when patients were retested. This shows that testing brought about less abuse by patients. The threat of
getting caught caused at least some patients to become c ompliant before the next urine test.
Also of note is that the study showed that there was little difference in abuse/ diversion rates between genders, ac ross ages, and
even across income levels. The problem is not limited to certain demographics but is widespread.
The Use of Opiates For Pain Management and the Problem of Drug Abuse
Dependence versus Addiction
Is everyone who needs opiates to help manage their pain addicted? Are all addicted people dependent?
The difference between addiction and dependency is important to note. Dependenc y refers simply to the biologica l
adaptation to a drug. Drug dependenc e means that a person needs a drug to function normally. Abruptly stopping the drug
would lead to withdrawa l symptoms in such a person. Many drugs elicit dependence, not just opiates.
Anyone who takes opiates for a moderate amount of time will become dependent. The drug becomes necessary for normal
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functioning. Increasing doses may also be needed due to tolerance. Tolerance occurs due to the fac t that opiate receptors will
down-regulate (reduce their expression) or activity in response to c hronic stimulation. As a result, it will take more drug to elicit the
same effect over time.
Although all addicts have dependence, not all those with dependenc y are addicts. Add iction is a more dubious term. Addiction is
the compulsive use of a substance, despite its negative or dangerous effects. Addiction is said to oc cur when a person c ontinues to
use a drug or even escalates the use of the drug in spite of the fact that it is causing social, physical, and economic harm to them
and others.
The Use of Opiates For Pain Management and the Problem of Drug Abuse
Ungraded Practice Question
Diversion is:
Plea se selec t the single b est answer
The Use of Opiates For Pain Management and the Problem of Drug Abuse
Ungraded Practice Question
Diversion is:
nmlkj Susbstituting one analgesic for another
nmlkj selling or giving one's medications to someone else
nmlkj using a drug without a prescription
nmlkj when a drug not prescribed is detected in the urine.
Plea se selec t the single b est answer
Feedback
Diversion occurs when a pa tient sells or gives their prescription drug to someone else. This is usually done for financial reasons.
Narcotics used for pain management are strong ana lgesics and have significant street value. It is common to find patients who
screen negative for a drug they were prescribed because they 'diverted' or sold the drug for cash.
nmlkj Susbstituting one analgesic for another
nmlkj selling or giving one's medications to someone else
nmlkj using a drug without a prescription
nmlkj when a drug not prescribed is detected in the urine.
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The Use of Opiates For Pain Management and the Problem of Drug Abuse
The Goal of Pain Management (PM)
There are several goa ls in the prac tice of PM.
Two obvious goals are:
1. Reduce or limit dependency on medica tions for pain control
2. Avoid add iction to pain medica tions
A primary tenet of PM is that a patient should not expect to be pain-free. C linicians will ask patients what their expectations are for
their pain control and will counsel them and explain that living pain-free is not a realistic goal. Few, it any, of us live pain-free.
Instead, the goa l of PM is to maximize a patient's quality of life; to get the patient to a plac e where he/ she can function despite
pain.
Opiates are not the only tools available to the PM clinician. Counseling, group therapy, physical therapy, exercise, enc ouraging
positive behaviors, ac upuncture, and even hypnosis can be tried. The PM clinician is concerned with getting the patient to a lower
pa in level using the lowest possible dose of a drug, or no drug a t all.
PM can usually only reduce subjective pain around 30%. Thus, it's important for pa tients to have realistic expectations. When using
drugs to lower pain the obvious goals of produc ing as few side effects as possible and having a daily plan to manage acute pain
and flare-ups are important as well.
Patients are often prescribed one opiate and are told to increase the dose temporarily, only if pa in flares up.
The Use of Opiates For Pain Management and the Problem of Drug Abuse
Testing the Pain Management (PM) Patient
The frequency of urine testing in PM depends on
the agreement made between the patient andclinician (the opiate therapy plan or contrac t), as
well as the na ture of the pa tient. Patients who
have a history of drug abuse or alcohol abuse
will require more frequent monitoring than those
at lower risk for addictive behaviors.
Many patients will present to clinicians
complaining of pain and will not be content to
leave the c linician's office without a prescription
for a narcotic. Patients who "doctor shop," trying
to get prescriptions for pain medication, are
relatively common. Some c haracteristics of
patients who exhibit drug-seeking behavior are
listed in the accompanying table. Prescribing
narcotics to patients who do not have a genuine
clinical need for them can cause clinicians to
lose their licenses to prescribe medica tions or
practice medicine. The stakes are high for
patients and clinicians when it comes to opiate
use. Thus, asking patients to undergo testing to
monitor appropriate prescription drug use should
not be seen as punitive but rather expected,
given the high abuse rates for prescription drugs
and the potential risk to the professional reputation of the ordering clinician.
Clinicians will often test the urine of patients prescribed opiates every six months. In cases of patients with abuse histories or
patients who have had previous abnormal urine screens, clinicians may elec t to have pa tients tested every time they refill their
prescription.
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Some health care organizations also a llow c linicians to order a pill count. A pill count is an order that instructs the pa tient to go to
the pharmac y and have the pharmac ist count how many opiate pills are remaining in the prescription c ontainer. The pharmacist
can easily tell if the pills are indeed the prescribed medication and whether or not there are too few remaining, given the elapsed
time period. Pill counts are another way to manage patients with suspicious behaviors.
Ordering urine DOA screens on PM patients is very useful to verify whether the patient is compliant with the PM plan. The c linician
expects to see the presence of the prescribed drug and will check to make sure that other abused drugs are not present.
One problem with urine screening in PM patients is that the collections are usually not supervised. Usually, patients are asked to
submit samples they collect themselves. This unsupervised collection means that patients could be submitting samples that are not
theirs, samples that have been c hemically altered, or samples that have been diluted. Supervised collec tions are more common in
addiction medicine clinics and less common in the PM setting. However, the line between PM and addiction medicine can quickly
blur.
Urine DOA screens are only useful if the c linician and the laboratory professionals know how to interpret the findings.
The Use of Opiates For Pain Management and the Problem of Drug Abuse
Ungraded Practice Question
Which statement be low is true?
Plea se selec t the single b est answer
The Use of Opiates For Pain Management and the Problem of Drug Abuse
Ungraded Practice Question
Which statement be low is true?
nmlkj The number of deaths resulting from opiate use is slowly decreasing due to laboratory testing efforts.
nmlkj It is uncommon to find more than one opiate or opioid in a patient's urine.
nmlkj About 2/3 of patients who have drug screens have an unexpected result.
Plea se selec t the single b est answer
Feedback
A recent study by Quest Diagnostics showed that 63% of patients had unexpected results.
The number of deaths and adverse events assoc iated with opiates has increased rapidly over the past five years and it is very
common to find more than one opiate/ opioid in patient samples.
nmlkj The number of deaths resulting from opiate use is slowly decreasing due to laboratory testing efforts.
nmlkj It is uncommon to find more than one opiate or opioid in a patient's urine.
nmlkj About 2/3 of patients who have drug screens have an unexpected result.
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The Use of Opiates For Pain Management and the Problem of Drug Abuse
Ungraded Practice Question
Which of the following drugs is a synthetic opioid with a very long duration of action and is used to help wean patients from
opiate dependency?
Plea se selec t the single b est answer
The Use of Opiates For Pain Management and the Problem of Drug Abuse
Ungraded Practice Question
Which of the following drugs is a synthetic opioid with a very long duration of action and is used to help wean patients from
opiate dependency?
nmlkj Codeine
nmlkj Morphine
nmlkj Hydromorphone
nmlkj Methadone
Plea se selec t the single b est answer
Feedback
Methadone is a synthetic opioid with a long duration of ac tion. Morphine and c odeine are true op iates whereas hydromorphone is
considered a semi-synthetic in that it is a metabolite o f morphine but is not found in the poppy plant.
The Use of Opiates For Pain Management and the Problem of Drug Abuse
Ungraded Practice Question
Which of the following is true?
nmlkj Codeine
nmlkj Morphine
nmlkj Hydromorphone
nmlkj Methadone
Plea se selec t the single b est answer
nmlkj Living pa in free is the goal for pain management pa tients
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The Use of Opiates For Pain Management and the Problem of Drug Abuse
Ungraded Practice Question
Which of the following is true?
nmlkj Pain management should occur over all the remaining years of a patient's life
nmlkj Hydrocodone is the most commonly prescribed narcotic in the US.
Plea se selec t the single b est answer
Feedback
Living pa in free is not a realistic expectation. Instead, patients are given the goal of trying to reduce their pa in so they can function
at a maximum level. Pain management should be a finite process. Chronic pain management is common but the goal is to wean
patients off of analgesics eventually. Hydrocodone is currently the most prescribed narcotic analgesic in the US.
The Use of Opiates For Pain Management and the Problem of Drug Abuse
Ungraded Practice Question
In the prac tice of pain management, the absence of a compound in the urine is often just as significant as the presence of a
compound.
nmlkj Living pa in free is the goal for pain management pa tients
nmlkj Pain management should occur over all the remaining years of a patient's life
nmlkj Hydrocodone is the most commonly prescribed narcotic in the US.
Selec t true or fa lse
The Use of Opiates For Pain Management and the Problem of Drug Abuse
Ungraded Practice Question
In the prac tice of pain management, the absence of a compound in the urine is often just as significant as the presence of a
compound.
nmlkj True
nmlkj False
Selec t true or fa lse
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The Use of Opiates For Pain Management and the Problem of Drug Abuse
Ungraded Practice Question
True or false: The goal of pain management is to have the patient live pa in-free.
nmlkj True
nmlkj False
Selec t true or fa lse
The Use of Opiates For Pain Management and the Problem of Drug Abuse
Ungraded Practice Question
True or false: The goal of pain management is to have the patient live pa in-free.
nmlkj True
nmlkj False
Selec t true or fa lse
Feedback
The goal of pain management is to maximize function and get patients to be as ac tive as they normally would be. Being pa in-free
is not a rea listic goal.
Interpretation of Drugs of Abuse Testing in Pain Managemen
Pain Management Drug Screen Interpretation Competencies
To interpret urine drug screen results confidently in the context of pain management, the clinical laboratory professional should
possess these competenc ies:
l Be able to recognize adulterated samples
l Know which opiate metabo lites would be expec ted with a given drug
l Know the cross-reactivities of the laboratory's immunoassay methods, or where to a ccess this information
l Be familiar with prescription pain drug trade names
l Be able to answer some of the common questions posed to toxicology laboratory personnel
nmlkj True
nmlkjFalse
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Interpretation of Drugs of Abuse Testing in Pain Managemen
Adulterants and Urine Samples Collected for Prescription Drug Monitoring
As discussed earlier, adulterants are c hemicals that can be a dded to a urine sample to obscure or confound drug screens.
Since most urine collections in the pain management setting are self-collec ted and unsupervised, it is easy for a person to
adulterate his/her specimen, if that person wishes to dec eive the clinician. Adulteration of a urine sample for drugs-of-abuse
screening, performed for employment or legal reasons, may be done to produce a false-negative result. However, adulteration
of the urine sample in the pa in management setting may be done to produce a false-positive result. That is, a pa tient may
adulterate the urine sample by adding the drug that should be there when in fac t, the patient did not ingest the drug. For
example, a patient who is being treated with methadone for an addiction to heroin may put methadone p ill dust into his/her urine
sample to trick the c linician into thinking he/she is compliant with taking the medication. In reality, the pa tient skipped the
methadone dose in order to get a greater "high" when using heroin or other opiates. For this reason, toxicology laboratories should
only report methadone as positive when they detec t the parent and the metabolite (the metabolite will only be present if the drug
was injected and not present if pill dust is added).
Interpretation of Drugs of Abuse Testing in Pain Managemen
Opiate Metabolites
In PM, a c onfirmation
should be performed if a
screening result is positive.
Since confirmatory methods
use mass spectrometry,
spec ific compounds can be
identified and quantitated.
However, we need to be
able to make sense of the
specific compounds that
are found.
The accompanying
diagram on the right and
table below contain
essentially all that is needed
to know about opiate
metabolism for routine PM
testing. Posting this
information in thelaboratory is very useful.
Laboratory testing
personnel may find that
they quickly memorize the parent and metabolite relationships when reviewing opiate confirmation results.
The information contained in the table below may be included with opiate confirmation results to help clinicians understand
the results.
Detected Drug Possible Parent Drug Detection Window
Codeine Codeine 2-3 days
Hydrocodone Hydrocodone, codeine, dihydrocodeine 2-3 days
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Interpretation of Drugs of Abuse Testing in Pain Managemen
The Problem with Oxycodone and Oxymorphone (Oxys) In Immunoassay Methods
A typical drugs-of-abuse (DOA) screen contains the following tests:
l Amphetamines
l THC
l Barbiturates
l
Benzodiazepinesl Methadone
l Cocaine
l Opiates
l Oxycodone/ Oxymorphone (oxys)
Notice that methadone, opiates, and oxycodone are all individually tested. This may seem strange since these are all
opioids/opiates. But the fac t is, there a re modifications to the chemical structures of opiates that will make them undetec table to
immunoassay methods that recognize the general prototype structure of morphine. As a result, it takes three immunoassays to
detect the three common opiate drugs/classes of methadone, opiates, and oxcodone/ oxymorphone (oxys). In general we c an
think of opiates and opioid screens in this way:
If a c linician fails to recognize that different immunoassays are needed to screen for different opioids, confusion will result. It is not
uncommon for clinicians to misinterpret screens and ac cuse patients of not taking their medica tions when in fac t the patient is
positive for the medication but the wrong screen was used. Clinicians may assume that any drug, which moderately resembles an
opiate in its ac tion, will be detec table using an op iate drug screen. This is not true. For example, one of the most commonly
prescribed drugs in the US, oxycodone, will not typically be detected on an opiate screen but instead requires a specific "OXY
screen."
It may be the case that a regular opiate immunoassay screen will pick up oxycodone, yet the OXY screen will usually not detect
regular opiates. For example, a patient taking morphine should be positive for opiates, but will likely be negative for oxys. Yet a
patient taking oxymorphone may be positive for oxys and positive on the opiates immunoassay screen as well. Note that
oxycodone and oxymorphone can produce a positive op iate screen as well as a positive OXY screen. However, codeine,
morphine, hydrocodone, and hydromorphone will typically not produce a positive OXY screen on most immunoassay instruments.
For these reasons it's critical that you know the performanc e of your laboratory's assays. The toxicology tec hnologist must be ab le to
reference the laboratory vendor's cross-reactivities information to know what to expect.
Hydromorphone Hydromorphone, hydrocodone, morphine 2-3 days
Morphine Morphine, codeine, heroin 2-3 days
Oxycodone Oxycodone 2-3 days
Oxymorphone Oxymorphone, oxycodone 2-3 days
Drug Screen Detects
Opiates Morphine, codeine, hydrocodone, hydromorphone
Oxys Oxycodone, oxymorphone
Methadone Methadone
Fentanyl Fentanyl
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Interpretation of Drugs of Abuse Testing in Pain Managemen
Cross-Reactivities
Every vendor will disclose a list of drugs that c an
cross-react with their immunoassay. This
information is essential for proper interpretation
of immunoassay results. In the immunoassay
example on the right, morphine is defined as the
standard (100%). Notice that some drugs, such as
codeine, are detected better than morphine
with this assay. Yet some drugs, like oxycodone,
oxymorphone, and meperidine, c ross-react less
than15%. That is, these drugs will not be detected
with sufficient sensitivity using this opiate screen.
Laboratory personnel need to educate c linicians
in how to use the laboratory's drug screen.
Laboratories may note in the patient results
which drugs of the same class are NOT detected
using their particular immunoassay, or may supply
an interpretation table so that clinicians are
aware that one assay cannot detec t all drugs of
a given class.
Interpretation of Drugs of Abuse Testing in Pain Managemen
Common Pain Management (PM) Drugs and Trade Names
The most commonly prescribed drugs for PM are listed in the table below along with some of their trade names. There are
more trade names; these are the more common ones in the US:
Prescription Drug Trade Names
Codeine Tylenol number 2, 3, etc., Codoplus, Codopyrin, Corex, Codin
Fentanyl Sublimaze,Durgesic, Duragesic, Fentora, Haldid, Onsolis,Instanyl, Abstral
Hydrocodone Dicodid, Duodin, Hycet, Hycodan Hydrococet, Lorcet, Lortab, Norco, Norgan,Panacet, Symtan, Synkonin,
Vicodin
Hydromorphone Dilaudid, Exalgo, Hydromorph Contin, Palladone
Meperidine Demerol
Methadone Symoron, Dolophine, Amidone, Methadose, Physeptone, Heptadon
Morphine Contin, Avinza, Kadian, Oramorph, Roxanol, Kapanol
Oxycodone Oxycontin, Oxecta, Roxicodone, Supeudol
Oxymorphone Opana , Numorphan, Numorphone
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Interpretation of Drugs of Abuse Testing in Pain Managemen
Ungraded Practice Question
Morphine is a metabolite of codeine.
Selec t true or fa lse
Interpretation of Drugs of Abuse Testing in Pain Managemen
Ungraded Practice Question
Morphine is a metabolite of codeine.
nmlkj True
nmlkj False
Selec t true or fa lse
Feedback
Codeine is metabolized in the body to morphine. Identifying the metabolites of specific opiates is essential when interpreting urine
drug confirmations in the c ontext of pain management.
Interpretation of Drugs of Abuse Testing in Pain Managemen
Half-Lives and Windows
One of the more c ommon questions the toxicology laboratory professional is asked by a patient is, "How long will it take
before I can pass a drug test." The c linician may ask, "How long should I expec t the patient's result to be positive?" The kinetics
of drug metabolism and the presence of parent drugs and metabolites in the urine can be hard to predict since urine is not a
homeostatically-controlled fluid. Urine concentration, unlike serum concentration, will vary significantly depending on how
much one drinks. Also, people metabolize drugs at different rates depending on age, the presence of other drugs, as well as
dietary and genetic factors. It takes around five half-lives for a d rug to become undetectable. A half-life is the amount of time
it takes for a drug concentration in the body to decrease by 50%.
Despite the variability in metabolism, a general rule of thumb c an be made for eac h of the drug c lasses. The information below
can serve a s a guideline:
nmlkj True
nmlkj False
Drug Half-life (hours) Approximate Window of Detection in Urine (days)
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Interpretation of Drugs of Abuse Testing in Pain Managemen
Ungraded Practice Question
Which of the following drugs is a metabolite o f another opiate but is also itself available as a prescription drug?
Ampheta mine 7-30 2-3
Barbiturate (long-ac ting) 80-120 5-10
Barbiturate (short-acting) 35-88 3-7
Benzodiazepines (long-ac ting) 21-37 7-10
Benzodiazepines (short-acting) 6-27 2-3
Benzoylecogonine (cocaine metabolite) 12-15 3-5
Coc aine 0.75-1.50 1
Codeine 2-4 2
Hydrocodone 3.5-9 2
MDMA 4-6 1-2
Methadone 15-55 3-7
Methamphetamine 6-15 2-3
Morphine 1.5-6.5 2-3
Oxycodone 4-6 2
THC 24-72 2-15
Plea se selec t the single b est answer
Interpretation of Drugs of Abuse Testing in Pain Managemen
Ungraded Practice Question
Which of the following drugs is a metabolite o f another opiate but is also itself available as a prescription drug?
nmlkj Codeine
nmlkj Oxycodone
nmlkj Hydromorphone
Plea se selec t the single b est answer
nmlkj Codeine
nmlkj Oxycodone
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Feedback
Hydromorphone is a metabolite of morphine and hydrocodone. A ll of these drugs are available with a prescription.
Interpretation of Drugs of Abuse Testing in Pain Managemen
Frequently Asked Questions (FAQs) To the Toxicology Laboratory
Although these questions are not all related to pain drugs, they are often asked by pain management (PM) clinicians so they
are worth addressing.
Will Nyquil cause a positive DOA screen?Nyquil contains ac etaminophen, dextromethorphan, doxylamine succ inate and
ethanol. With high consumption, the alcohol content could ca use a positive alcohol screen but it should not cause
immunoassays for DOA to be falsely positive at normal doses (Note: a lways refer to your assay's cross-reactivity specs).
My patient is taking Adderall for ADHD/ADD. Why are they positive for amphetamine?The drug Adderall contains both isomers of
amphetamine. It is therefore not surprising that when amphetamine is prescribed, the urine will test positive for amphetamine.
My patient is taking methyphenidate (Ritalin) for ADHD/ADD why is the test not positive for amphetamines?Methylphenidate is not
structurally similar to amphetamine. Although both drugs are used in ADHD/ADD, it should not be assumed that both will cause
positive amphetamine results. Methylphenidate will not be detected with routine drug screens.
Do poppy seeds really cause positive opiate screens?Yes this is possible, as discussed earlier in the course.
Does dose correlate with urine concentration?No. Since urine concentration varies dramatically depending on how much a person
drinks we cannot treat a quantitative urine drug result like we would a serum result. Although we have minimum cutoffs for drug
detection in urine, there are no therapeutic ranges or 'target' ranges. Urine concentration does not parallel serum concentration in
a predictable or reliable way.
Does the drug zolpidem (Ambien) cause a positive benzodiazepine screen?No. Zolpidem is not a benzodiazepine; it belongs to a
different class of drugs. Although zolpidem is a sleeping aid (a hypnotic) it will not cause a false benzo or barbiturate screen.
My patient says he/she tested positive for THC due to second-hand smoke. Is this possible?No. The amount of time and exposure i
would take to have the urine positive would essentially deem such exposure first-hand and not second-hand exposure.
Will tramadol, fentanyl, buprenorphine or carisoprodol be detected by the opiate/Oxy screen?No. None of these drugs will
typica lly cause a positive result. Specific testing for these agents is needed if the c linician wants to monitor their use.
Interpretation of Drugs of Abuse Testing in Pain Managemen
Ungraded Practice Question
Scenario 1
A patient with a urine creatinine of 25 mg/dL who has reportedly been taking codeine has codeine present in her urine but no
morphine present. Which statement is true?
nmlkj Hydromorphone
Plea se selec t the single b est answer
nmlkj The urine is adulterated, so the confirmation is not reliable
nmlkj The parent drug is detected, which is expected. The metabolite morphine need not be detected to ca ll the patient compliant
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Interpretation of Drugs of Abuse Testing in Pain Managemen
Ungraded Practice Question
Scenario 1
A patient with a urine creatinine of 25 mg/dL who has reportedly been taking codeine has codeine present in her urine but no
morphine present. Which statement is true?
nmlkj A positive result for morphine would not be expected if codeine was taken.
nmlkj Without the presence of both codeine and morphine, it can be concluded that the patient is noncompliant.
Plea se selec t the single b est answer
Feedback
If the patient takes codeine we would expec t codeine and perhaps morphine. However the finding of metabolite is not essential in
this case. The drug may have been recently consumed and so significant amounts of morphine may not yet be present. The urine is
dilute but >20 mg/ dL. However, with a dilute urine the sensitivity of the assay for morphine may be dec reased. Finding both parent
and metabolite is useful but not essential to determining compliance.
Interpretation of Drugs of Abuse Testing in Pain Managemen
Scenario 2
A clinician calls and says the laboratory made an error on the opiate screen he had ordered for one of his patients to detect
methadone, which was being prescribed for this patient. The c linician states that the patient always takes his/her methadone
at the correct time each day, yet the urine opiate screen is negative. The clinician also wonders why the urine creatinine is
flagging abnormal (it is 15 mg/dL).
Why is the opiate screen negative if the patient is taking methadone regularly as prescribed?
What does the abnormal creatinine result probably indica te?
nmlkj The urine is adulterated, so the confirmation is not reliable
nmlkj The parent drug is detected, which is expected. The metabolite morphine need not be detected to ca ll the patient compliant
nmlkj A positive result for morphine would not be expected if codeine was taken.
nmlkj Without the presence of both codeine and morphine, it can be concluded that the patient is noncompliant.
Consider why the opiate screen is negative if the patient is taking methadone regularly. Then c lick on this text to
compare your response to the correct response.
Consider what the abnormally low creatinine result probably indicates. Then c lick on this text to compare your
response to the correct answer.
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Interpretation of Drugs of Abuse Testing in Pain Managemen
Scenario 2
A clinician calls and says the laboratory made an error on the opiate screen he had ordered for one of his patients to detect
methadone, which was being prescribed for this patient. The c linician states that the patient always takes his/her methadone
at the correct time each day, yet the urine opiate screen is negative. The clinician also wonders why the urine creatinine is
flagging abnormal (it is 15 mg/dL).
Why is the opiate screen negative if the patient is taking methadone regularly as prescribed?
What does the abnormal creatinine result probably indica te?
Feedback
Interpretation of Drugs of Abuse Testing in Pain Managemen
Ungraded Practice Question
Scenario 3
A c linician has a pa tient
taking Vicodin 750-7.5 mg
daily (The numbers refer to
750 mg acetaminophen
and 7.5 mg hydrocodone
per tablet).
The lab reported finding
hydromorphone in the
confirmation, but does not
report a positive result for
hydrocodone. The clinician
is now asking the
toxicology laboratory
tec hnologist if this result is
consistent with the patient's
prescription.
Which of the following is a
correct response?
Consider why the opiate screen is negative if the patient is taking methadone regularly. Then c lick on this text to
compare your response to the correct response.
Consider what the abnormally low creatinine result probably indicates. Then c lick on this text to compare your
response to the correct answer.
Plea se selec t the single b est answer
nmlkj Yes the result is consistent with the
prescribed medication. Hydromorphone is a
metabolite of hydrocodone and perhaps
only metabolite is present in the urine.
nmlkj No it is not consistent with the prescribed
medication. Hydrocodone should be
positive bec ause it is present in the
prescribed medication.
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Interpretation of Drugs of Abuse Testing in Pain Managemen
Ungraded Practice Question
Scenario 3
A c linician has a pa tient
taking Vicodin 750-7.5 mgdaily (The numbers refer to
750 mg acetaminophen
and 7.5 mg hydrocodone
per tablet).
The lab reported finding
hydromorphone in the
confirmation, but does not
report a positive result for
hydrocodone. The clinician
is now asking the
toxicology laboratory
tec hnologist if this result is
consistent with the patient's
prescription.
Which of the following is a
correct response?
Plea se selec t the single b est answer
Feedback
The findings are consistent with the prescription.
Since the patient is taking hydrocodone the
finding of hydromorphone makes sense because
hydromorphone is a metabolite of hydrocodone.
The fact that there was no hydrocodone found is
a bit unusual but not impossible. If the patient
missed a dose, it's possible that only metabolite
and no parent drug is present in the urine.
nmlkj Yes the result is consistent with the
prescribed medication. Hydromorphone is a
metabolite of hydrocodone and perhaps
only metabolite is present in the urine.
nmlkj No it is not consistent with the prescribed
medication. Hydrocodone should be
positive bec ause it is present in the
prescribed medication.
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The fact that there was no hydrocodone parent
drug found may be c oncerning to the c linician if the patient says that he/ she took a tablet recently. However, it is not good
laboratory practice to look at ratios of parent to metabolite to try and guess the time of the last dose. As stated previously in the
course, urine conc entrations don't reflec t serum concentrations and c an't be used to firmly establish drug kinetics.
Interpretation of Drugs of Abuse Testing in Pain Managemen
Summary
In summary, pain management has become a significant d river and utilizer for lab toxicology testing. Screening and
confirming opiates, and other drugs, in the urine of pa tients being prescribed analgesics has become very common. The abuse
of prescription medications (opiates) is a serious and growing problem. The laboratory can play a vital role in assessing the
compliance of patients and in assisting clinic ians in their management o f PM patients. Because many physicians who prac tice
PM are not trained in toxicology or even PM (and are often only primary care physicians learning PM as they go), they often
need help interpreting laboratory results. The laboratorian can provide a key service to c linicians in PM and addiction medicine
if they are able to:
l Explain their screening a ssay's performanc e and cross reactivitiesl Help make sense of results given the prescription of the pa tient
l Identify adulterated samples
l Answer routine questions about what services and which drugs the lab c an detec t and not detect.
The laboratorian can take an active role in PM. Onc e the value of the knowledgeable toxicology technologist is known to a
clinician group that technologist will quickly bec ome a reference and resource for many clinicians. Such recognition helps to
elevate one's scope of prac tice, self esteem and the practice of laboratory medicine.
Interpretation of Drugs of Abuse Testing in Pain Managemen
Ungraded Practice Question
A patient with hydrocodone, hydromorphone,
codeine, and morphine in his/her urine would
likely be taking which of the following drug
combinations?
Plea se selec t the single b est answer
nmlkj Codeine and morphine
nmlkj Oxycodone and hydrocodone
nmlkj Morphine and oxymorphone
nmlkj Hydrocodone and hydromorphone
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Interpretation of Drugs of Abuse Testing in Pain Managemen
Ungraded Practice Question
A patient with hydrocodone, hydromorphone,
codeine, and morphine in his/her urine would
likely be taking which of the following drug
combinations?
Plea se selec t the single b est answer
Feedback
Codeine will give rise to morphine and (to a
lesser extent) hydrocodone. Morphine will result in
the hydromorphone metabolite. Thus, given the
choices, only codeine and morphine will give this
finding.
Reference
References
Brunton L, Lazo J , Parker K.Go od m a n & G i lm an 's The Pharma c olog ica l Bas is of Therap eut ics. 11th ed. McGraw-Hill, 2005.
Burtis CA, Ashwood ER, eds. Tietz Textb oo k of C l in ica l Chem istry and Mo lecu lar Dia gn ost ics, 4th ed. Philadelphia: WB Saunders,
2005.
Kaplan LA, Pesce A, Kazmierczak S. Clinic a l Ch em istry: The ory, A na lysis, C orrelation. 4th ed. New York: Mosby, 2002.
Perrine D. The Che m istry of Mind-Al ter ing Drugs: History , Pha rma c olog y, and Cul tura l Co ntext .American Chemical Soc iety
Publication, 1996.
Quest Diagnostics, Study Report on Urine Testing for Prescription Drugs. January 2011.
Reisfield et al.,C l in C hem, 2009: 55 1765-1768.
nmlkj Codeine and morphine
nmlkj Oxycodone and hydrocodone
nmlkj Morphine and oxymorphone
nmlkj Hydrocodone and hydromorphone
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