Profile of idiosyncratic drug induced liver injury in Latin America. An analysis of published reports

Drug-induced Liver Injury in Latin America: 10-year Experience of the Latin American DILI (LATINDILI) Network

BACKGROUND & AIMS

Latin America is a region of great interest for studying the clinical presentation of idiosyncratic drug-induced liver injury (DILI). A comprehensive analysis of patients enrolled into the LATINDILI Network over a decade is presented.

METHODS

Demographics, clinical presentation, histological findings and outcome of prospectively recruited DILI cases in the LATINDILI Network were analyzed. Suspected culprit drugs were classified according to the Anatomical Therapeutic Chemical classification. Causality was assessed using the Roussel Uclaf Causality Assessment Method (RUCAM) scale.

RESULTS

Overall, 468 idiosyncratic DILI cases were analyzed (62% women; mean age, 49 years). Hepatocellular injury predominated (62%); jaundice was present in 60% of patients, and 42% were hospitalized. Of the cases, 4.1% had a fatal outcome, and 24 patients (12%) developed chronic DILI. The most common drug classes were systemic anti-infectives (31%), musculoskeletal agents (12%), antineoplastic and immunomodulating agents (11%), and herbal and dietary supplements (9%). Notably, none of the patients with DILI due to antibacterials or immunosuppressants had a fatal outcome. In fact, Hy's law showed to have drug-specific predictive value, with anti-tuberculosis drugs, nimesulide, and herbal and dietary supplements associated with the worst outcome, whereas DILI caused by amoxicillin-clavulanate, nitrofurantoin, and diclofenac, which fulfilled Hy's law, did not have a fatal outcome.

CONCLUSION

Features of DILI in Latin America are comparable to other prospective registries. However, the pattern of drugs responsible for DILI differs. An increasing incidence of herbal and dietary supplements, with high mortality rate, and likewise, nimesulide and nitrofurantoin, was noted. Thus, public health policies should raise awareness of the potential adverse effects of these compounds.

Clinical Features, Laboratory Characteristics and Outcome from Oral Contraceptives-induced Liver Injury in 43 Consecutive Patients and a Brief Review of Published Reports

Background

Hormonal oral contraceptive (OC) agents such as estrogen or progesterone, either as single agents or in combination, and a non-hormonal drug like ormeloxifene are used for various conditions. However, estrogen and progesterone-containing OC as well as ormeloxifene are seldom associated with hepatotoxicity. We prospectively studied the clinical, demographic, liver injury pattern, complications, and outcome of the hepatotoxicity from OC and ormeloxifene.

Methods

We analyzed and compared the aforementioned characteristics among consecutive patients with OC and ormeloxifene-induced drug-induced liver injury (DILI) from two university hospitals in India. Cases fulfilling established DILI criteria and the Roussel Uclaf causality assessment method were identified and followed up until recovery/death.

Results

We identified 43 (3.5%) amongst 1226 patients with DILI; 19 (44%) from estrogen and progesterone combination, 21 (49%) from progesterone monotherapy, and 3 (7%) due to ormeloxifene. Seven cases were identified from 1998 to 2014 and 36 cases from 2015 to 2023. All were due to oral tablets. The mean age was 36 years (range 21-75). Nineteen patients (44%) developed jaundice and 5 (11.6%) developed itching. The liver injury pattern was hepatocellular in 19 (44%), mixed in 13 (30%), and cholestatic in 11 (26%). Four patients (9%) died, three from acute liver failure and one due to acute on chronic liver failure. Liver biochemical tests normalized after a mean of 66 days after stopping the implicated agents. Contrastingly, literature search yielded 24 cases of progesterone DILI reported between 1962 and 2019 with no mortality.

Conclusion

In contrast to published literature on oral contraceptives, a majority of oral contraceptive-induced DILI in our series were from progesterone monotherapy and a smaller number with ormeloxifene, that often resulted in clinically significant jaundice or liver test abnormalities and rarely in fatality.

Drug-induced liver injury: A management position paper from the Latin American Association for Study of the liver

Idiosyncratic drug-induced liver injury (DILI) caused by xenobiotics (drugs, herbals and dietary supplements) is an uncommon cause of liver disease presenting with a wide range of phenotypes and disease severity, acute hepatitis mimicking viral hepatitis to autoimmune hepatitis, steatosis, fibrosis or rare chronic vascular syndromes. Disease severity ranges from asymptomatic liver test abnormalities to acute liver failure. DILI has been traditionally classified in predictable or intrinsic (dose-related) or unpredictable (not dose-related) mechanisms. Few prospective studies are assessing the real prevalence and incidence of hepatotoxicity in the general population. DILI registries represent useful networks used for the study of liver toxicity, aimed at improving the understanding of causes, phenotypes, natural history, and standardized definitions of hepatotoxicity. Although most of the registries do not carry out population-based studies, they may provide important data related to the prevalence of DILI, and also may be useful to compare features from different countries. With the support of the Spanish Registry of Hepatotoxicity, our Latin American Registry (LATINDILI) was created in 2011, and more than 350 DILI patients have been recruited to date. This position paper describes the more frequent drugs and herbs-induced DILI in Latin America, mainly focusing on several features of responsible medicaments. Also, we highlighted the most critical points on the management of hepatotoxicity in general and those based on findings from our Latin American experience in particular.

Mycophenolate Mofetil Hepatotoxicity Associated With Mitochondrial Abnormality in Liver Transplant Recipients and Mice

OBJECTIVES

Mycophenolate mofetil (MMF) is a widely used immunosuppressive agent. MMF hepatotoxicity has been reported in non-transplant and renal transplant patients with minimal histologic description. This is the first study describing detailed histology and ultrastructure of MMF hepatotoxicity.

METHODS

Four liver-transplant recipients (Cases 1-4) were suspected to have MMF hepatotoxicity. Cases 1-3 (two females and one male; 4-17 years) had multiple biopsies for liver function test (LFT) abnormalities. Case 4 (female; 16 years) had a surveillance biopsy. Electron-microscopic examination (EM) was requested on Cases 1-3 for unexplained, persistent LFT elevation and histologic abnormalities despite therapy and Case 4 for unexplained histologic abnormalities despite a stable clinical course. To confirm the pathologic changes in the human allografts, livers from MMF-treated and untreated mice were also reviewed.

RESULTS

While the allograft biopsies showed nonspecific histologic changes, EM revealed unequivocal mitochondrial abnormalities similar to those seen in primary and secondary mitochondrial disorders. In Cases 1 and 2, LFTs improved after stopping and reducing MMF, respectively. In Case 3, pre- and post-MMF treatment biopsies were performed and only the post-MMF biopsy demonstrated mitochondrial abnormalities. Mitochondrial abnormality in Case 4 was subclinical. The mouse study confirmed that MMF caused various stress changes in the mitochondria; number of mitochondria/cell (mean ± standard deviation; untreated group: 58.25 ± 8.426; MMF-treated group: 76.37 ± 18.66), number of lipid droplets/cell (untreated: 0.9691 ± 1.150; MMF-treated: 3.649 ± 4.143) and sizes of mitochondria (μm, untreated: 0.8550 ± 0.3409; MMF-treated: 0.9598 ± 0.5312) were significantly increased in hepatocytes in the MMF-treated mice compared with the untreated mice (P < 0.0001).

CONCLUSIONS

Although MMF is safe for the majority of patients, MMF can cause mitochondrial stress, which may trigger more severe mitochondrial abnormalities in a small subset. MMF hepatotoxicity should be considered for MMF-treated patients with unexplained, persistent LFT abnormalities and nonspecific histologic findings. EM should be requested for these cases.

Drug and herb-induced liver injury: A critical review of Brazilian cases with proposals for the improvement of causality assessment using RUCAM

INTRODUCTION AND OBJECTIVES

Although hepatotoxicity accounts for 10% of adverse drug reactions, it remains poorly understood and underreported. This study aimed to summarize case reports of herb- and drug-induced liver injury in Brazil.

METHODOLOGY

Systematic review in the following databases: PubMed, SciELO, Science Direct, CAPES, and gray literature.

RESULTS

Twenty-seven studies reporting 32 cases were identified. Brazilian cases were primarily detected in hospitals, and occurred mainly in young males suffering from chronic diseases. Drugs (n=29) were a more frequent cause of liver injury than herbs (n=3). Almost a third of these drugs were anticonvulsants, and 15 appear in the Brazilian List of Essential Medicines. In 50% of the cases, clinical manifestations started within 30 days of drug ingestion. Regarding the decline of liver enzymes, 50% of the cases reached normality after drug withdrawal. However, 7 deaths and 2 liver transplantations were reported. Only one study assessed causality using RUCAM.

CONCLUSION

Given the severe outcomes of DILI and HILI, early detection and management of hepatotoxicity to increase drug safety are necessary, as well as pharmacotherapeutic monitoring of patients with chronic diseases. Moreover, the application of the RUCAM algorithm in clinical practice has to be further disseminated.

Profile of herbal and dietary supplements induced liver injury in Latin America: A systematic review of published reports

Hepatotoxicity related to HDS is a growing global health issue. We have undertaken a systematic review of published case reports and case series from LA from 1976 to 2020 to describe the clinical features of HDS related hepatotoxicity in this region. We search in PubMed, Web of Science, Scopus and specific LA databases according to PRISMA guidelines. Only HILI cases published in LA that met criteria for DILI definition were included. Duplicate records or reports that lacked relevant data that precluded establishing causality were excluded. Finally, 17 records (23 cases) were included in this review. Centella asiatica, Carthamus tinctorius, and Herbalife® were the most reported HDS culprit products, the main reason for HDS consumption was weight loss. The clinical characteristics of HDS hepatotoxicity in our study were compared to those of other studies in the USA, Europe and China showing a similar signature with predominance of young females, hepatocellular damage, a high rate of ALF and mortality, more frequent inadvertent re-challenge and chronic damage. This study underscores the challenge in causality assessment when multi-ingredients HDS are taken and the need for consistent publication practice when reporting hepatotoxicity cases due to HDS, to foster HDS liver safety particularly in LA.

Epidemiology of drug-induced liver injury in a University Hospital from Colombia: Updated RUCAM being used for prospective causality assessment

INTRODUCTION AND AIM

Epidemiological information regarding drug-induced liver injury in some Latin American countries remains limited. Therefore, disease prevention and health promotion strategies are imperative to reduce drug-induced liver injuries and its fatal outcomes. This study aimed to collect epidemiological data regarding drug-induced liver injury and identify associated factors in patients admitted to a university hospital in Colombia.

METHODS AND PATIENTS

A prospective study was conducted for 1 year to assess the incidence of drug-induced liver injury in patients aged >18 years who showed elevated values in liver tests. Data were collected after obtaining informed consent from the patients. The updated Roussel Uclaf Causality Assessment Method was applied to assess the causality of drug-induced liver injury.

RESULTS

The study included 286 patients with elevated values in liver tests, 18 of whom presented with drug-induced liver injury. The mean age of patients was 54.7±19.1 years. The associated pharmacological groups were anti-infectives and anticonvulsants (isoniazid, rifampicin, nitrofurantoin, phenytoin, and valproic acid), with a total of 15 drugs. The affected patients presented with cytopenia, jaundice, nausea, vomiting, or hepatomegaly. The most common type of liver injury was hepatocellular, and most patients recovered satisfactorily. The number of patients who had highly probable and probable causality grading was 1 and 9, respectively.

CONCLUSION

The incidence of drug-induced liver injury in a university hospital in Colombia was 6%. Comorbidities and concomitant drugs are risk factors for drug-induced liver injury.

TRIAL REGISTRATION

Registered in The Cuban Public Registry of Clinical Trials (identifier RPCEC00000242).

PROSPECTIVE MONITORING OF DRUG USE: DRUG-INDUCED LIVER INJURY IN A PRIMARY HEALTHCARE CENTER

BACKGROUND

Drug-induced liver injury is still misunderstood in Brazil due to diagnostic difficulties or lack of reporting incidents.

OBJECTIVE

To assess the frequency of adverse events related to the use of medicines in a primary healthcare unit, in a city locate southwestern of the state of Bahia, Brazil.

METHODS

Prospective study conducted at the Primary Center for Specialized Health (CEMEA), February at August of 2013 in Vitoria da Conquista, Bahia, Brazil. Interviews were conducted with patients over 18 years old, and their clinical and laboratorial data were collected. The CIOMS scale was used to validate the cases.

RESULTS

A total of 149 patients, mainly Afro-Brazilian women, received follow-up. Among these patients, three cases of hepatotoxicity were identified, and the medicines associated to drug-induced liver injuries were: nimesulide, budesonide and valacyclovir.

CONCLUSION

Drug-induced liver injury is rare in primary healthcare units. It also allowed estimating the incidence of hepatotoxicity induced by allopathic medicines which are standardized by public healthcare authorities.

Idiosyncratic Drug-Induced Acute Liver Failure: A Challenging and Distressing Scenario

BACKGROUND

Idiosyncratic Drug Induced Liver Injury (DILI) is a rare adverse event to drugs that occasionally leads to severe liver damage, being one of the leading causes of Acute Liver Failure (ALF) in developed countries. DILI is largely a diagnosis of exclusion.

DISCUSSION AND CONCLUSION

Careful history of drug taking and ruling out other competing etiologies is mandatory given that DILI can present with an extremely variable phenotype. Several prognostic scores have been developed to promptly identify patients with potential risk of developing ALF. New biomarkers to diagnose and predict DILI evolution are under study and hopefully we will benefit from these novel tools in the near future.

Idiosyncratic DILI: Analysis of 46,266 Cases Assessed for Causality by RUCAM and Published From 2014 to Early 2019

One of the most difficult challenges in clinical hepatology is the diagnosis of a drug-induced liver injury (DILI). The timing of the events, exclusion of alternative causes, and taking into account the clinical context should be systematically assessed and scored in a transparent manner. RUCAM (Roussel Uclaf Causality Assessment Method) is a well-established diagnostic algorithm and scale to assess causality in patients with suspected DILI. First published in 1993 and updated in 2016, RUCAM is now the worldwide most commonly used causality assessment method (CAM) for DILI. The following manuscript highlights the recent implementation of RUCAM around the world, by reviewing the literature for publications that utilized RUCAM, and provides a review of “best practices” for the use of RUCAM in cases of suspected DILI. The worldwide appreciation of RUCAM is substantiated by the current analysis of 46,266 DILI cases, all tested for causality using RUCAM. These cases derived from 31 reports published from 2014 to early 2019. Their first authors came from 10 countries, with China on top, followed by the US, and Germany on the third rank. Importantly, all RUCAM-based DILI reports were published in high profile journals. Many other reports were published earlier from 1993 up to 2013 in support of RUCAM. Although most of the studies were of high quality, the current case analysis revealed shortcomings in few studies, not at the level of RUCAM itself but rather associated with the work of the users. To ensure in future DILI cases a better performance by the users, a list of essential elements is proposed. As an example, all suspected DILI cases should be evaluated 1) by the updated RUCAM to facilitate result comparisons, 2) according to a prospective study protocol to ensure complete data sets, 3) after exclusion of cases with herb induced liver injury (HILI) from a DILI cohort to prevent confounding variables, and 4) according to inclusion of DILI cases with RUCAM-based causality gradings of highly probable or probable, in order to increase the specificity of the results. In conclusion, RUCAM benefits from its high appreciation and performs well provided the users adhere to published recommendations to prevent confounding variability.

Idiosyncratic DILI: Analysis of 46,266 Cases Assessed for Causality by RUCAM and Published From 2014 to Early 2019

One of the most difficult challenges in clinical hepatology is the diagnosis of a drug-induced liver injury (DILI). The timing of the events, exclusion of alternative causes, and taking into account the clinical context should be systematically assessed and scored in a transparent manner. RUCAM (Roussel Uclaf Causality Assessment Method) is a well-established diagnostic algorithm and scale to assess causality in patients with suspected DILI. First published in 1993 and updated in 2016, RUCAM is now the worldwide most commonly used causality assessment method (CAM) for DILI. The following manuscript highlights the recent implementation of RUCAM around the world, by reviewing the literature for publications that utilized RUCAM, and provides a review of "best practices" for the use of RUCAM in cases of suspected DILI. The worldwide appreciation of RUCAM is substantiated by the current analysis of 46,266 DILI cases, all tested for causality using RUCAM. These cases derived from 31 reports published from 2014 to early 2019. Their first authors came from 10 countries, with China on top, followed by the US, and Germany on the third rank. Importantly, all RUCAM-based DILI reports were published in high profile journals. Many other reports were published earlier from 1993 up to 2013 in support of RUCAM. Although most of the studies were of high quality, the current case analysis revealed shortcomings in few studies, not at the level of RUCAM itself but rather associated with the work of the users. To ensure in future DILI cases a better performance by the users, a list of essential elements is proposed. As an example, all suspected DILI cases should be evaluated 1) by the updated RUCAM to facilitate result comparisons, 2) according to a prospective study protocol to ensure complete data sets, 3) after exclusion of cases with herb induced liver injury (HILI) from a DILI cohort to prevent confounding variables, and 4) according to inclusion of DILI cases with RUCAM-based causality gradings of highly probable or probable, in order to increase the specificity of the results. In conclusion, RUCAM benefits from its high appreciation and performs well provided the users adhere to published recommendations to prevent confounding variability.

Peroxisome proliferator-activated receptor alpha-mediated drug toxicity in the liver

INTRODUCTION

Drug-induced hepatic injury is the most common cause of acute liver failure in the United States. Peroxisome proliferator-activated receptor alpha (PPARα)-mediated drugs are included among the approximately 900 natural and synthetic substances, which have shown hepatotoxicity. Areas covered: This review will focus on fibrates - PPARα agonists and their implication in causing liver injury. Expert opinion: Compelling evidence for fibrate-induced hepatotoxicity is not available. Results have been varying because several large randomized clinical trials have reported similar elevations of plasma transaminase levels in fibrate or placebo treated groups. On the other hand, one meta-analysis has reported an increased risk of hepatotoxicity when fibrates are combined with statins. Fibrate induced clinically apparent liver damage has been demonstrated in case reports. However, there is a wide spectrum of clinical phenotypic presentations of these cases (onset of injury, pattern of enzyme elevation and resolution of the symptoms), which reduces the ability to identify specific cause and effect of any putative fibrate-induced hepatotoxicity. Thus, the current recommendations for using fibrates include monitoring of aminotransferase levels especially if combined with statins and discontinuation of the treatment only if the levels persist above three times the upper limit of normal.

Classification and Epidemiologic Aspects of Acute Liver Failure

Acute liver failure is a rare condition with high short-term morbidity and mortality. The most widely accepted definition is an abnormality in coagulation with any degree of encephalopathy in a patient without cirrhosis and an illness duration of less than 26 weeks. Multiple classifications systems are currently in use to help categorize the condition. This article reviews the most commonly used systems. The epidemiologic aspects of the disease are also reviewed, including incidence, prevalence, demographics, geographic distribution, and racial and cultural factors and are discussed for the various subtypes of acute liver failure.

Acute liver failure induced by idiosyncratic reaction to drugs: Challenges in diagnosis and therapy

Acute liver failure (ALF) requires urgent attention to identify etiology and determine prognosis, in order to assess likelihood of survival or need for transplantation. Identifying idiosyncratic drug-induced liver injury (iDILI) may be particularly difficult, but the illness generally follows a subacute course, allowing time to assess outcome and find a liver graft if needed. Not all drugs that cause iDILI lead to ALF; the most common are antibiotics including anti-tuberculous medications, non-steroidal anti-inflammatory agents and herbal and dietary supplements (HDS). Determining causality remains challenging particularly if altered mentation is present; identifying the causative agent depends in part on knowing the propensity of the drugs that have been taken in the proper time interval, plus excluding other causes. In general, iDILI that reaches the threshold of ALF will more often than not require transplantation, since survival without transplant is around 25%. Treatment consists of withdrawal of the presumed offending medication, consideration of N-acetylcysteine (NAC), as well as intensive care. Corticosteroids have not proven useful except perhaps in instances of apparent autoimmune hepatitis caused by a limited number of agents. Recently developed prognostic scoring systems may also aid in predicting outcome in this setting.

Monocyte-derived hepatocyte-like cells for causality assessment of idiosyncratic drug-induced liver injury

BACKGROUND

Idiosyncratic drug-induced liver injury (iDILI) is a frequent cause of acute liver injury and a serious problem in late stage drug-development. Its diagnosis is one of the most challenging in hepatology, since it is done by exclusion and relies on expert opinion. Until now no reliable in vitro test exists to support the diagnosis of iDILI. In some instances it is impossible to determine the causative drug in polymedicated patients.

AIM

To investigate if monocyte-derived hepatocyte-like (MH) cells might be a tool supporting clinical judgment for iDILI diagnosis and causality assessment.

METHODS

This prospective study included 54 patients with acute liver injury and intake of at least one drug. Thirty-one patients were diagnosed with iDILI based on causality likelihood. MH cells were generated from every patient and in vitro toxicity of the respective drugs was assessed by lactate-dehydrogenase release. The results from MH cells and RUCAM, the most widely used scoring system as methods to support clinical judgement were compared.

RESULTS

MH cells showed enhanced toxicity in 29 of the 31 patients with iDILI, similar to RUCAM score. MH cells exhibited negative results in the 23 non-DILI cases, whereas RUCAM indicated possible iDILI in six cases. Analysis of the comedications also showed superior specificity of MH cells. No MH cell toxicity of the drugs showing toxicity in patients with iDILI was observed in MH cells of healthy donors.

CONCLUSIONS

In this pilot study in vitro testing using MH cells derived from patients with acute liver injury was able to identify patients with iDILI with an excellent sensitivity and a higher specificity than RUCAM, the most widely used current causality assessment score. Therefore, MH cells could be useful to identify the causative drugs even in polymedicated patients by adding objective data to causality assessment.

TRIAL REGISTRATION NUMBER

NCT02353455.

Hepatotoxicity due to Clindamycin in Combination with Acetaminophen in a 62-Year-Old African American Female: A Case Report and Review of the Literature

Clindamycin is a bacteriostatic lincosamide antibiotic with a broad spectrum. Side effects include nausea, vomiting, diarrhea, and metallic taste; however, hepatotoxicity is rare. The incidence is unknown. It is characterized by increases in aspartate and alanine transaminases. There may be no symptoms and the treatment is to stop the administration of clindamycin. We have described a 62-year-old African American female medicated with acetaminophen and clindamycin who had initially presented to the dental clinic for the evaluation of gum pain following tooth extraction. She had significantly increased levels of liver transaminases, which trended downwards on quitting the medication.

The Latin American DILI Registry Experience: A Successful Ongoing Collaborative Strategic Initiative

Drug induced liver injury (DILI) is a rare but well recognized serious adverse reaction. Pre-marketing studies may not detect liver injury, and DILI becomes very often apparent after the drug is launched to the market. Specific biomarkers for DILI prediction or diagnosis are not available. Toxic liver reactions present with a wide spectrum of phenotypes and severity, and our knowledge on the mechanisms underlying idiosyncratic reactions and individual susceptibility is still limited. To overcome these limitations, country-based registries and multicenter research networks have been created in Europe and North America. Reliable epidemiological data on DILI in Latin America (LA), a region with a large variety of ethnic groups, were however lacking. Fortunately, a LA network of DILI was set up in 2011, with the support of the Spanish DILI Registry from the University of Malaga. The primary aim of the Latin DILI Network (LATINDILIN) Registry was to prospectively identify bona fide DILI cases and to collect biological samples to study genetic biomarkers. Physicians involved in the project must complete a structured report form describing the DILI case presentation and follow-up which is submitted to a Coordinator Center in each country, where it is further assessed for completeness. During the last four years, several LA countries (Argentina, Uruguay, Chile, Mexico, Paraguay, Brazil, Ecuador, Peru, Venezuela and Colombia) have joined the network and committed with this project. At that point, to identify both our strengths and weaknesses was a very important issue. In this review, we will describe how the LATINDILI Registry was created. The aims and methods to achieve these objectives will be discussed in depth. Additionally, both the difficulties we have faced and the strategies to solve them will be also pinpointed. Finally, we will report on our preliminary results, and discuss ideas to expand and to keep running this network.

Categorization of drugs implicated in causing liver injury: Critical assessment based on published case reports

An important element in assessing causality in drug-induced liver injury is whether the implicated agent is known to cause hepatotoxicity. We classified drugs into categories based on the number of published reports of convincingly documented, clinically apparent, idiosyncratic liver injury. Drugs described in the website LiverTox (http://livertox.nih.gov) were classified into five categories based on the number of published cases (category A, ≥50; category B, 12-49; category C, 4-11; category D, 1-3; category E, none). Case reports in categories C and D were individually reanalyzed using the Roussel Uclaf Causality Assessment Method. Drugs with fatal cases or with rechallenge were noted. Among 671 individual drugs or closely related agents, 353 (53%) were considered convincingly linked to liver injury in published case reports; 48 (13%) were assigned to category A, 76 (22%) were assigned to category B, 96 (27%) were assigned to category C, and 126 (36%) were assigned to category D. Another 7 (2%) were direct hepatotoxins but only in high doses and placed in a separate category (T). The remaining 318 (47%) drugs had no convincing case report of hepatoxicity in the literature (category E). All except one in category A have been available since 1999, 98% had at least one fatal case and 89% a positive rechallenge. In category B, 54% had a fatal case and 41% a rechallenge. Drugs in categories C and D less frequently had instances of fatal (23% and 7%) or rechallenge cases (26% and 11%).

CONCLUSION

Documentation of hepatoxicity in the medical literature is variable, and many published instances do not stand up to critical review. A standardized system for categorizing drugs for hepatotoxicity potential will help develop objective and reliable, computer-based instruments for assessing causality in drug-induced liver injury.