DRUG INDUCED LIVER INJURYHEPATOTOXICITY FROM DRUGS,

SUPPLEMENTS AND HERBAL COMPOUNDS

Internal Medicine Core CurriculumLily Dara, M.D.

Assistant Professor of MedicineDepartment of Medicine, Division of GI/Liver

USC Research Center for Liver DiseaseKeck School of Medicine

Objectives■ After this presentation, the listener should be able to:

1. Understand importance of drug induced liver injury (DILI)2. Identify the major clinical presentations of DILI3. Recognize the most common causes of DILI (direct and

idiosyncratic)4. Identify the major conditions to exclude in making the

diagnosis of drug-induced liver injury5. Understand the mechanism of acetaminophen (APAP) induced

liver failure (the most common cause of acute live failure in the US).

Why is DILI important ■ Drug-induced liver Injury (DILI) represents an important problem – (1) Many drugs cause DILI (approximately 1,000 drugs have been implicated) – (2) DILI is the most common cause of acute liver failure (ALF), approximately 50%

(although acetaminophen (tylenol) accounts for the bulk of these, other drugs are still a more frequent cause ALF than viral hepatitis and other causes)

– (3) DILI represents an important diagnostic/therapeutic challenge for physicians caring for patients presenting with liver disorders, since it can mimic all forms of acute or chronic liver disease

– (4) The frequency and economic impact of this problem is a major challenge for the pharmaceutical industry and regulatory bodies, especially since the toxic potential of many drugs has not been evident in preclinical studies and may even be missed in Phase I-III clinical testing. This results in withdrawal from the market, restrictions or termination of projects. : Troglitazone, bromphenac, trovafloxacin, bosentan, telithromycin, lumiracoxib, ximelagatran, tolvaptan

Incidence and manifestation of DILI

■ Surveys from France and Iceland 14-17/100,000

■ However >50% of ALF presenting to the hospital is due to DILI

■ Of 76 drugs withdrawn from the market between 1969 and 2002, 12 were attributable to liver damage

■ Manifestations of DILI are numerous, however the most common are: Drug induced icteric hepatitis (hepatocellular jaundice, high AST/ALT and Bilirubin) or cholestatic liver disease. The former is of grave significance, as mortality approximates 10% irrespective of the specific drug.

Liver Function Tests and Enzymes§ Liver FUNCTION tests are tests

that denote the synthetic capacity of the liver, when they are abnormal they denote acute or chronic liver failure:

– Protein– Albumin– Bilirubin– INR (factor 7)– Most proteins are made in the liver

§ Liver enzymes are released from dying or damaged liver cells. When hepatocytes are damaged “hepatitis” with elevated:§ AST (asparate amino transferase)§ ALT (alanine amino transferase)

§When cholangiocytes are damaged (bile duct lining), “cholestaticinjury”§ ALP (alkaline phosphatase)§GGT

1. The bulk of adverse hepatic drug reactions present with an acute hepatitis, cholestasis or mixed signature. Although some drugs present a narrow signature, others have a very broad signature. Chronicity is being increasingly recognized.

2. Acute drug hepatitis with jaundice is life threatening (10% mortality) (Hy’s Law)

3. Cholestatic reactions resolve slowly and can lead to chronic ductopenia (cirrhosis rare)

Important Facts About Drug-Induced Liver Disease

Hy’s Law■ Named after the late Hymann Zimmerman who observed 10%-50% mortality with

DILI and jaundice– Unlike in viral hepatitis: ~ 1%– Drug-induced cholestatic hepatitis: ~1%

■ Most cases of fatality were jaundiced (HIGH BILIRUBIN) and had an ALT and AST of 8-100 x ULN with ALP being<3 x ULN

■ R Value >5 (next slide)

■ In the more severe cases à coagulopathy and encephalopathy, which are indicative of acute (fulminant) liver failure.

■ Cholestatic cases have more prominent ALP and with clinical pruritus; cholestaticreactions tend to resolve very slowly (i.e., months versus weeks for hepatitis) and on rare occasion lead to vanishing bile duct disease and biliary cirrhosis. Not ALF.

*R-Value Definition of the Phenotypes of DILI or Patterns

Liver Injury Definition:ALT > 3x (5x) ULN or ALP > 2 X ULN + Total Bilirubin

Lesser abnormalities are considered abnormal liver tests

Hepatocellular ALT ALP > 5ULN ULN

Cholestatic < 2

Mixed 2 - 5

R-value

DILI Network (NIDDK): Patterns of Injury

Hepatocellular54%

Cholestatic23%

Mixed23%

899 Cases

Hepatocellular Cholestatic Mixed

Chalasani et al, Gastroenterology 2008

Spectrum of Clinical Hepatic Manifestations of DILI

*Drug Induced Liver Injury Direct vs Idiosyncratic

Direct toxicity

■ Predictable such as APAP, chemotherapeutics■ Dose Dependent

■ Short latency

■ Cholestatic agents have a milder phenotype.

■ Commonly occurs to everyone taking the drug beyond a certain dose

Idiosyncratic DILI (IDILI)

■ “Unpredictable” and “Unexpected”

■ Not dose dependent

■ Variable latency (sometimes long)

■ Host factors are crucial such as age, gender and SNPs are important

■ Rare event (Clinical trials Post-marketing)

Direct Hepatotoxicity

■ Expected outcome, dose related• Acetaminophen• Aspirin (Reye)• Many antineoplastic agents■ Serum enzyme elevations■ Acute hepatic necrosis■ Sinusoidal obstruction syndrome■ Lactic acidosis, steatosis, hepatic dysfunction■ Nodular regenerative hyperplasia

Mitochondrial toxicity■ Rare but dramatic syndrome with

some drugs■ Lactic acidosis, microvesicular

steatosis, hepatic necrosis■ Nausea, anorexia, fatigue →

stupor/coma■ ALT, ALP & bilirubin initially minimally

elevated■ Lactate, INR, ammonia ↑↑■ Slow recovery if drug stopped in time■ Stavudine, Didanosine, Fialuridine,

Linezolid, Tetracycline (iv), Amiodarone, Aspirin (Reye Syndrome)

Microvesicular Steatosis

Macrovesicular Steatosis

Diagnosis of DILI: Exclusion of other causes

Viral hepatitisHBSAg, anti-HBC-IgManti-HAV-IgManti-HCV, HCV RNAanti-HEV IgM (HEV RNA)anti-EBV, CMV, Herpes-IgM and PCR

Autoimmune Hepatitis:ANA, ASMA, elevated IgG

*Some drugs cause similar picture to AIHBiliary tract obstruction:

ultrasound, MRCP

Hypotension, hypoxia, CHF –ischemic hepatitis

SepsisHeavy alcohol consumption- typical

picture of ALD

Make sure to ask about herbals and dietary supplements

Risk Factors for DILI

■ Age, gender, combination therapy, drug dosage and the presence of underlying liver diseases

■ A cholestatic pattern of injury, irrespective of the drug involved, is more common in the elderly. (augmentin DILI in young patients hepatitis vs older cholestatic)

■ Historically, women were thought to be at increased risk for DILI, but more recent studies show no gender predilection.

■ Women are, however, more likely to express a hepatocellular pattern of injury and are more likely to develop acute liver failure.

■ The Acute Liver Failure Study Group demonstrated that the female preponderance in ALF is seen in cases of idiosyncratic drug reactions (67%) as well as cases due to acetaminophen (74%).

Risk Factors for DILIExamples of risk factors for DILIDrug Risk factorsAcetaminophen Chronic alcohol use, fasting, female sex, INH use

INH Hepatitis B, Hepatitis C, HIV, alcohol use, older age, female sex, rifampin or pyrizinamide use, slow acetylator

Methotrexate Chronic alcohol use, obesity, diabetes mellitus, chronic hepatitis, psoriasis

Valproate sodium Young age, antiepileptic drug use, genetic defects in mitochondrial beta-oxidation

Sulfonamides HIV, slow acetylator

Diclofenac Female sex, osteoarthritis

Erythromycin Young age

Halothane Obesity

Adapted from Kaplowitz, N.; DeLeve, L., Eds.; Drug-Induced Liver Disease, 1st ed.; Marcel Dekker: New York, 2002.

Acute Liver Failure (ALF)

■ ALF is a rare, life-threatening condition characterized by rapid deterioration of liver function reflected in altered mentation and coagulopathy, in the absence of underlying liver disease, in less than 26 weeks.

■ United States estimates are placed at approximately 2,000 cases per year

■ DILI accounts for over one-half of such cases in the United States with an estimated 46% of cases attributed to acetaminophen and an additional 12-15% attributed to idiosyncratic drug reactions

U.S. Acute Liver Failure

Acetaminophen 46% ~ 1/2 unintentional overdose

Idiosyncratic DILI 12% (IDILI)

Indeterminate 15% (APAP + AIH)

Viral Hepatitis 11%

Autoimmune 5%

Miscellaneous 11%

Lee et al ALFSG data

BLOOD HEPATOCYTE BILE

Non-toxic Metabolite

Why is the liver a major target for drugs?

Phase 1: Cytochrome P450s (Cyp) Phase 2: Conjugations: UGT, sulfotransferases, GSH S-transferases, N-AcetyltransferasesPhase 3: Canalicular transporters ( MRP2, BSEP)

Drug Metabolism

Cyp

Direct Injury Immune Response

Toxic Metabolite

DRUG

Cyp2e1

GSHconjugateGlucuronideSulfate

APAP NAPQIcovalentbinding

↓↓GSH

FirstPhase

MitochondriaMPT

Necrosis

SecondPhase

ATP

DNAdamageSwelling

AIFreleaseSignal

Pathway to Acetaminophen (APAP) Toxicity

(non-toxic)

MPT=mitochondrialpermeabilitytransition

(GSHdepletion)

ROS

Transduction(JNK)

NAC

Acetaminophen (APAP) Toxicity

• ~1/2 ALF cases in the USA• 50% suicidal overdose(>10g at once); • 50% unintentional (7 g/d. x 3d)• Safe up to 3g/d (previously 4gr/d)?

– CYP2E1 inducers (ethanol, INH)– Starvation (↓GSH ↓glucuronic acid)– Cirrhotic patients

• Presentation– Towering transaminases begin day 2 in the thousands (hepatocyte death) – INR abnormal early– Minimal hyperbilirubinemia

Safe up to 2g/d.

APAP■ APAP is metabolized by cytochrome P-450 enzymes (CYP2E1, CYP1A2, CYP3A4,

and CYP2D6) to a reactive intermediary metabolite: N-acetyl-p benzoquinone imine (NAPQI)

■ NAPQI is highly electrophilic and highly reactive, it binds intracellular proteins and causes cellular stress especially mitochondrial and ER stress.

■ At nontoxic doses, NAPQI is efficiently detoxified by glutathione (GSH) forming an acetaminophen-GSH conjugate

■ The importance of hepatic glutathione was shown by Mitchell et al. (1973) in APAP-DILI in mice, showed that administration of cysteine the precursor to GSH, prevented hepatotoxicity.

■ This led to the development of N-acetyl-cysteine or NAC (available as MucomystTM ) as the preferred antidote to replenish GSH stores.

■ NAC should be given within 8 hours of a massive over dose.

APAP 4gm/day in healthy subjects

40% >3xuln

STOP

Watkins, JAMA 296; 87-93, 2006

Rumack-Mathew Nomogram■ The standard acetaminophen toxicity

nomogram may aid in investigating the likelihood of serious liver damage, but cannot exclude the possibility of toxicity due to multiple doses over time, or altered metabolism in the alcoholic or fasting patient.

■ Given these considerations, administration of NAC is advised in any case of ALF in which acetaminophen overdose is a suspected or possible cause.

■ Survival from APAP induced ALF is upwards of 65%

King’s College Criteria

Predict survival following ALF from APAPArterial pH < 7.3 (after adequate volume resuscitation) irrespective of coma grade-or-Lactate >3.5 mmol/L –or–Prothrombin time > 100 s or INR > 6.5 + Serum creatinine > 3.4 mg/dl) +Grade III/IV coma (Polson and Lee 2005) ■ Severe acidosis was associated with a mortality 95%

Treatment■ Always call poison control n (1-800-222-1222 )

■ Activated charcoal used in the ER if acute over dose within 4hrs. Charcoal should be withheld in patients who cannot protect their airway.

■ There are no RCTs for evaluating the efficacy of N-acetylcysteine for the prevention of hepatic injury—unethical not to treat

■ However, retrospective and cohort data compared to historic controls shows NAC decreases incidence of ALF and coma.

■ ALF is uncommon and death extremely rare if NAC given within 8hrs of ingestion

■ If NAC administered late (after 8hrs) in patients who already have liver failure, it still can improve coma grade, hepatic function and DECREASE MORTALITY

■ The incidence of hepatotoxicity for patients treated within 8hrs of ingestion is <10%, but increases to approximately 40% if treatment is delayed beyond 16hrs

■ 20hr intravenous (IV) protocol and 72hr PO protocol– There are no head to head trials– Both are effective

– IV is preferred in patients who already present with hepatic failure or are vomiting Smilkstein N Engl J Med. 1988;319(24):1557. and MJ Ann Emerg Med. 1991;20(10):1058.

IDIOSYNCRATIC DILI (IDILI)

DILIN Study – Idiosyncratic DILI

■ Antimicrobials – 45.5 % includes anti-TB and anti-virals: Augmentin, nitrofurantoin, INH, Bactrim, cipro, levo, terbinafine

■ CNS agents – 15% anti-epileptics, antidepressants, antipsychotics: duloxetine, valproate, phenytoin, lamotrigine

■ Immunomodulators and analgesics – 10.5% e.g. interferon-β, diclofenac

■ Dietary supplements – 9%

Chalasani et al, Gastroenterology. 2008

Idiosyncratic DILI does NOT occur in the majority of patients exposed to the drug

■ Tolerant – No liver injury (90-99%)

■ Adaptor – Mild liver injury resolves despite continued treatment (1-10%)

■ Susceptible – Initial liver injury progresses to clinically significant e.g.,

jaundice, symptoms, ALF (0.01% - 1%)

Top 10 causes of IDILI

Chalasani et al: Am J Gastroenterology 2014

Antimicrobials are the most common causes followed by NSAIDs, anticonvulsants and, increasingly, herbal and dietary supplements.

IDILI■ ALF cases due to IDILI have poorer overall survival when compared to APAP-related

ALF with spontaneous survival rates of only 26% compared to 65% for APAP.

■ Most examples of idiosyncratic drug hepatotoxicity occur within the first 6 months after drug ingestion, whereas a drug that has been used continuously for more than 1–2 years, while not impossible, is unlikely to cause de-novo liver damage.

■ Idiosyncratic drug-related ALF is a diagnosis of exclusion. R/O other causes first

■ Treatment for idiosyncratic drug related ALF is limited and usually supportive, with withdrawal of the offending agent; however with transplant, survival approaches 70%.

■ One trial suggests early NAC infusion may play a role; in patients with ALF and early (grade I-II) coma, improved transplant-free survival was noted (Lee et al., 2009).

■ Corticosteroids have proven ineffective and even harmful especially in high MELDs (Karkhanis et al., 2014).

NAC in non-APAP ALF

Lee et al, Gastroenterology 2009

NAC in non-APAP ALF

Diagnosis of DILI: RUCAM model

§ Latency: usually new drug started and continued within 6 months (2 days to 12 months)§ Some antibiotics (amoxicillin-clavulanic acid, erythromycin) – onset

delayed 1-2 months after course of treatment§ De-challenge: stop drug →improve (slower in cholestatic) rate of

improvement very variable§ Re-challenge: not safe!§ Previous knowledge about the drug: literature, PDR (drug well known to

cause DILI)§ Exclusions

Diagnosis: Guilt by Association

■ High index of suspicion – stop treatment, assess response, rule out other causes

■ Look for characteristic signature and latency

■ Assume it is DILI if liver disease occurs with characteristic latency + signature (hepatitis, cholestasis) for the drug and no other cause.

■ Liver biopsy (histopathology) can be helpful.(eosinophilic infiltrate, granuloma, centrilobular coagulative necrosis)

Diagnostic Challenges ■ Broad Signature– (e.g. amoxicillin - clavulanate)

■ Atypical latency – Very short (e.g. telithromycin) Very long (e.g. nitrofurantoin)

■ Confounding factors– Underlying illness- sepsis, CHF , liver disease, cancer, HIV, innocent

bystander, multiple drugs and dietary supplements

■ Distinction from AIH

■ Background noise – Cryptic liver diseases “Hidden” causes - hepatitis E, herbals

Immune-allergic DILI § DRESS + TEN with accompanying DILI: carbemazepine, phenytoin,

sulfonamides, allopurinol 1. Drug activated latent herpes virus2. Innocent bystander liver injury

§ Immune-allergic DILI with allergic features (rash, eosinophilia, re-challenge) 1. Halothane2. Hydralazine

§ Auto-Immune Hepatitis like, AIH-DILI 1. Drug-induced AIH– nitrofurantoin, minocycline, alph-methyl dopa, hydralazine2. Drug-activated – statins, IFN, TNF antagonists§ MOST COMMON: Idiosyncratic DILI without allergic features (immune, HLA

mediated)

SNPs■ Single nucleotide polymorphisms, frequently called SNPs (pronounced “snips”), are the

most common type of genetic variation.

■ Each SNP represents a difference in a single nucleotide. For example, a SNP may replace the nucleotide such as a cytosine (C) with the nucleotide thymine (T) or vice versa in a certain stretch of DNA.

■ SNPs occur normally in everyone at arte of about every 300 nucleotides (on average), which means there are roughly 10 million SNPs in the human genome

■ SNPs can also be used to track the inheritance of disease

■ SNPs can occur in the introns (between genes) or in the exon region of genes

■ Many snps in the (Human Leukocyte Antigen) HLA molecules have been associated with DILI.

■ Since HLA or MHC molecules are cell surface molecules that participate in antigen recognition in the immune system, this indicates a possible link between IDILI and the immune system

HLA alleles in DILI, the role of SNPs

DRUG PHENOTYPE HLA other associations

Flucloxacillin cholestatic B* 5701 Abacavir rash

Ximelagatran hepatocellular DRB1*0701 AIH 2 and ? TB meds DQA1*0201 Caucasians

Ticlopidine cholestatic A*3303 Asians

Nevirapine hepatocellular DRB*0101 low CD4 protective

Amoxicillin - Clavulanate Spectrum DRB1*1501 DRB1*07 protectiveCholestatic to Hepatocellular DGB1*0602 PSC, ? halothane

? Nitrofurantoin

Lapatinib hepatocellular and DQA1*0201 Ximelagatranmixed (delayed) DQB1*0202

DRB1*0701

Lumiracoxib hepatocellular DRB1*1501 Amoxicillin - clavulanate(delayed) DQB1*0602 multiple sclerosis

DRB5*0101DQA1*0102

Lumiracoxib DILI (HLA-DQA1*0102)

Nature Genetics 2010

GWAS on 201 Cases of Augmentin Hepatotoxicity

Entire Genome

MHC region: Chromosome 6

Lucena et al, Gastroenterology 2011

Hapten Hypothesis

§ The Hapten hypothesis postulates a drug is bioactivated and converted into a

“reactive metabolite” that covalently binds proteins and forms neoantigens,

eliciting cellular stress. This neoantigen is then taken up by the immune system.

In certain individuals with susceptible HLAs (Single nucleotide polymorphisms

or SNPs) due to molecular mimicry the neoantigen can be perceived as

“foreign”. HLA variants (SNPs) with enhanced affinity for neoantigens result in

intensified presentation of the neoantigen to T cells, T cell activation and

consequently liver injury due immunologically mediated hepatocyte death.

ADAPTATION IN IDILI

Adaptation Hypothesis in IDILI

Exposure HazardCell Stress Mild injuryInnate immunity

Sufficient Adaptation

Insufficient Adaptation

InjuryRecovery

Idiosyncratic DILI: Clinical Adaptation

Tolerant:

No liver injury

Adaptor:

Mild liver injury resolves despite continued tx

Susceptible:

Initial liver injury progresses to clinical significance (jaundice, ALF)

(90-99%) (1-10%) (0.01% - 1%)

0.1

1.0

10.0

100.0

-8 -4 0 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60

weeks

M49w M49w

M61b M61b

M39b M39b

AS

T, T

BL:

Log

10(x

ULN

)

on INH

Mitchell, et al., 1975

22.1x30.7x

14.6x

4.3x

2.8x3.3x

AST Bilirubin

Adapted from Mitchell, et al., 1975 Courtesy of Dr. J. Senior

Adaptation: “Hy’s Law Cases” due to INH

INH facts■ INH is associated with transient serum aminotransferase elevations in 10% to 20% of patients, and

levels rising above 5x ULN in 3% to 5%. These enzyme elevations are usually asymptomatic and often resolve even with continuation of therapy without dose adjustment.

■ However, INH can also cause clinically apparent acute liver injury with jaundice, which arises in 0.5% to 1% and is fatal in 0.05 to 0.1% of recipients.

■ Manifests 2 weeks to 6 months after starting INH.

■ Pattern is hepatocellular with marked increases in ALT levels (>10 times ULN) and minimal increases in alkaline phosphatase values (usually <2 times ULN)

– Self-limited and begins to resolve within a week of stopping

■ AGE is an important factor in INH DILI: The rates of clinically apparent hepatitis due to INH are estimated at 0.5% in patients 20 to 35 years of age, 1.5% in those 35 to 50 years of age, and 3% or higher in persons above the age of 50 years.

– Other RF: preexisting liver disease (hepatitis B or C), concurrent use of rifampin or pyrazinamide, and possibly alcoholism, black race and genetic factors.

– ALF from INH more common in women and AA

INH■ Important to monitor with liver panels generally monthly.

■ Monitoring is recommended in everyone but particularly in those with pre-existing liver disease and over 50.

■ Mild elevations unclear what to do…. If RF for severe disease (such as cirrhosis) stop! Close follow up for those with no RF as most people will adapt? Unclear….

■ Important! appearance of any symptoms of hepatitis (fatigue, nausea, poor appetite or jaundice) accompanied by liver enzyme elevations should lead to the immediate discontinuation of isoniazid.

■ DC INH if ALT above 5 times the ULN (or above 3 times ULN in the presence of symptoms) – Remember the ULN of ALT is 19 for women and 31 for men

■ Pts need to be carefully instructed and regularly reminded to pay attention to new onset of symptoms of fatigue or nausea that persist for more than a day and, if symptoms arise, to have serum enzyme levels tested promptly

■ Even with monitoring, INH remains a major cause of acute liver failure due to idiosyncratic reactions, and is associated with several instances of acute liver failure and death or emergency liver transplantation in the United States each year.

New Forms of “DILI” ■ Immune Modulators - ? Induce autoimmunity

– High dose methylprednisolone bolus.

– Biologics – interferon, anti-TNF.

– Immune check point inhibitors!

■ HDS

– Anabolic steroids – cholestatic (?High ALT, low ALP – biopsy cholestasis)

– Mostly “idiosyncratic” (weight loss): green tea extract, adulterants,

misidentification of plants, multiple ingredients. Kava, germander, Crotalaria,

Lipokenetix, usnic acid, Herbalife, Hydroxycut, OxyElitePro, (aegeline).

Drugs that cause asymptomatic increased ALT without jaundice

• Heparins – common in hospitalized patients

• Cholestyramine

• Statins

─ Rare: severe DILI (1 per million)

─ Some cases develop AIH 1-2 months after starting statin (seems to

unmask true AIH)

HERBAL AND DIETARY SUPPLEMENTS

Herbals and Dietary Supplements■ Increasing used in the US

■ Not regulated (DSHEA act of 1993)

– No studies

– Possible adulteration of products

■ Increasingly implicated in liver injury

■ Diverse, often poorly defined agents

■ Phenotypes

– Bland cholestasis

– Acute hepatitis-like

Rising Proportion of DILICaused by Herbals & Dietary Supplements

■ Two major groups

– Anabolic steroids: Young man with jaundice pruritus, bland cholestasis, Often protracted, rarely fatal.

– Other HDS, Chinese medications, weight loss products, epigallocatechin gallate (EGCG), etc

DILIN Repository for HDSDILIN: 85 cases of HDS-induced liver injury

143 different HDS products have been implicated in DILI, most with multiple constituents.

Most commonly implicated:

Product name NoSlim Quick 6Hydroxycut 5Herbalife 4Right Approach 3Airborne 2Move Free 1

DILIN registry, Courtesy of Dr. Hoofnagle , NIDDK

Other References■ Kaplowitz N, DeLeve L, Drug Induced Liver Injury, Third Edition Elsevier, eBook ISBN: 9780123878182, Hardcover ISBN: 9780123878175

■ Kullak-Ublick, GA. Drug-induced liver injury: recent advances in diagnosis and risk assessment. Gut 2017 Jun;66(6):1154-1164. doi: 10.1136/gutjnl-2016-313369. Epub 2017 Mar 23.

■ Hayashi PH, Fontana RJ. Clinical Features, diagnosis and natural history of drug induced liver injury. Semin Liver Dis. 2014 May;34(2):134-44. doi: 10.1055/s-0034-1375955. Epub 2014 May 31. Review.

■ Wysowski DK, Adverse Drug Event Surveillance and Drug Withdrawals in the United States, 1969-2002 Arch Intern Med 2005;165:1363–9

■ Fontana RJ, Persistent liver biochemistry abnormalities are more common in older patients and those with cholestatic DILI. Am J Gastroenterol. 2015 Oct;110(10):1450-9. doi: 10.1038/ajg.2015.283. Epub 2015 Sep 8.

■ Reuben A, Drug-induced acute liver failure: results of a U.S. multicenter, prospective study. Hepatology. 2010 Dec;52(6):2065-76. doi: 10.1002/hep.23937. Epub2010 Oct 14.

■ Navarro VJ, et al Liver injury from herbal and dietary supplements. Hepatology 2017 Jan;65(1):363-373. doi: 10.1002/hep.28813. Epub 2016 Nov 17.

■ Motamedi N., Dara, L, Kaplowitz N. Clinical considerations in DILI. Comprehensive Toxicology, Third Edition. 2017 Elsevier

■ Polson J., Lee W.M. AASLD position paper: the management of acute liver failure. Hepatology2005, 1179–1197.

■ Watkins PB, Kaplowitz N, Slattery JT, et al. Aminotransferase elevations in healthy adults receiving 4 grams of acetaminophen daily: a randomized controlled trial. JAMA 2006;296:87–93.

■ Yang M., et al. 2014. Biomarkers distinguish apoptotic and necrotic cell death during hepatic ischemia/reperfusion injury in mice. Liver Transpl, 20, 1372-82.

■ Cummings, J., et al. 2008. Preclinical evaluation of M30 and M65 ELISAs as biomarkers of drug induced tumor cell death and antitumor activity. Mol Cancer Ther, 7, 455-63.

■ Lea J. D., et al. 2015. Redox-dependent HMGB1 isoforms as pivotal co-ordinators of drug-induced liver injury - mechanistic biomarkers and therapeutic targets. Antioxid Redox Signal.

■ Lee, W. et al. & Acute Liver Failure Study Group. 2009. Intravenous N-acetylcysteine improves transplant-free survival in early stage non-acetaminophen acute liver failure. Gastroenterology, 137, 856-64, 864 e1.