Drug-induced liver injury: results from the hospital-based Berlin Case-Control Surveillance Study

Angelicin: A leading culprit involved in fructus Psoraleae liver injury via inhibition of VKORC1

ETHNOPHARMACOLOGICAL RELEVANCE

The adverse effects of Fructus Psoraleae (FP), especially liver injury, have attracted wide attention in recent years.

AIM OF THE STUDY

To establish a system to explore potential hepatotoxic targets and the chief culprit of liver injury based on clinical experience, network pharmacological method, molecular docking, and in vitro and in vivo experiments.

MATERIALS AND METHODS

Clinical applications and adverse reactions to FP were obtained from public literatures. Components absorbed in the blood were selected as candidates to search for potential active targets (PATs) of FP. Subsequently, potential pharmacological core targets (PPCTs) were screened through the "drug targets-disease targets" network. Non-drug active targets (NPATs) were obtained by subtracting the PPCTs from the PATs. The potential hepatotoxic targets (PHTs) of FP were the intersection targets obtained from Venn analysis using NPATs, hepatotoxic targets, and adverse drug reaction (ADR) targets provided by the databases. Then, potential hepatotoxic components and targets were obtained using the "NPATS-component" network relationship. Molecular docking and in vitro and in vivo hepatotoxicity experiments were performed to verify the targets and related components.

RESULTS

Overall, 234 NPATs were acquired from our analysis, and 6 targets were identified as PHTs. Results from molecular docking and in vitro and in vivo experiments showed that angelicin is the leading cause of liver injury in FP, and VKORC1 plays an important role.

CONCLUSION

The results indicate that six targets, especially VKORC1, are associated with the PHTs of FP, and angelicin is the leading culprit involved in FP liver injury via inhibition of VKORC1.

Advances in Idiosyncratic Drug-Induced Liver Injury Issues: New Clinical and Mechanistic Analysis Due to Roussel Uclaf Causality Assessment Method Use

Clinical and mechanistic considerations in idiosyncratic drug-induced liver injury (iDILI) remain challenging topics when they are derived from mere case narratives or iDILI cases without valid diagnosis. To overcome these issues, attempts should be made on pathogenetic aspects based on published clinical iDILI cases firmly diagnosed by the original RUCAM (Roussel Uclaf Causality Assessment Method) or the RUCAM version updated in 2016. Analysis of RUCAM-based iDILI cases allowed for evaluating immune and genetic data obtained from the serum and the liver of affected patients. For instance, strong evidence for immune reactions in the liver of patients with RUCAM-based iDILI was provided by the detection of serum anti-CYP 2E1 due to drugs like volatile anesthetics sevoflurane and desflurane, partially associated with the formation of trifluoroacetyl (TFA) halide as toxic intermediates that form protein adducts and may generate reactive oxygen species (ROS). This is accompanied by production of anti-TFA antibodies detected in the serum of these patients. Other RUCAM-based studies on serum ANA (anti-nuclear antibodies) and SMA (anti-smooth muscle antibodies) associated with AIDILI (autoimmune DILI) syn DIAIH (drug-induced autoimmune hepatitis) provide additional evidence of immunological reactions with monocytes as one of several promoting immune cells. In addition, in the blood plasma of patients, mediators like the cytokines IL-22, IL-22 binding protein (IL-22BP), IL-6, IL-10, IL 12p70, IL-17A, IL-23, IP-10, or chemokines such as CD206 and sCD163 were found in DILI due to anti-tuberculosis drugs as ascertained by the prospective updated RUCAM, which scored a high causality. RUCAM-based analysis also provided compelling evidence of genetic factors such as HLA (human leucocyte antigen) alleles contributing to initiate iDILI by a few drugs. In conclusion, analysis of published RUCAM-based iDILI cases provided firm evidence of immune and genetic processes involved in iDILI caused by specific drugs.

Molecular Idiosyncratic Toxicology of Drugs in the Human Liver Compared with Animals: Basic Considerations

Drug induced liver injury (DILI) occurs in patients exposed to drugs at recommended doses that leads to idiosyncratic DILI and provides an excellent human model with well described clinical features, liver injury pattern, and diagnostic criteria, based on patients assessed for causality using RUCAM (Roussel Uclaf Causality Assessment Method) as original method of 1993 or its update of 2016. Overall, 81,856 RUCAM based DILI cases have been published until mid of 2020, allowing now for an analysis of mechanistic issues of the disease. From selected DILI cases with verified diagnosis by using RUCAM, direct evidence was provided for the involvement of the innate and adapted immune system as well as genetic HLA (Human Leucocyte Antigen) genotypes. Direct evidence for a role of hepatic immune systems was substantiated by (1) the detection of anti-CYP (Cytochrome P450) isoforms in the plasma of affected patients, in line with the observation that 65% of the drugs most implicated in DILI are metabolized by a range of CYP isoforms, (2) the DIAIH (drug induced autoimmune hepatitis), a subgroup of idiosyncratic DILI, which is characterized by high RUCAM causality gradings and the detection of plasma antibodies such as positive serum anti-nuclear antibodies (ANA) and anti-smooth muscle antibodies (ASMA), rarely also anti-mitochondrial antibodies (AMA), (3) the effective treatment with glucocorticoids in part of an unselected RUCAM based DILI group, and (4) its rare association with the immune-triggered Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) caused by a small group of drugs. Direct evidence of a genetic basis of idiosyncratic DILI was shown by the association of several HLA genotypes for DILI caused by selected drugs. Finally, animal models of idiosyncratic DILI mimicking human immune and genetic features are not available and further search likely will be unsuccessful. In essence and based on cases of DILI with verified diagnosis using RUCAM for causality evaluation, there is now substantial direct evidence that immune mechanisms and genetics can account for idiosyncratic DILI by many but not all implicated drugs, which may help understand the mechanistic background of the disease and contribute to new approaches of therapy and prevention.

Drug-Associated Liver Injury Related to Antipsychotics: Exploratory Analysis of Pharmacovigilance Data

BACKGROUND

Drug-associated liver injury is one of the most common causes for acute liver failure and market withdrawal of approved drugs. In addition, the potential for hepatotoxicity related to specific substances has to be considered in psychopharmacotherapy. However, systematic evaluations of hepatotoxicity related to antipsychotics are limited.

METHODS

We conducted an exploratory case/non-case study and evaluated pharmacovigilance data from VigiBase related to 30 antipsychotics marketed in the European Union. Reporting odds ratios were calculated for antipsychotics associated with the Standardized Medical Dictionary of Regulatory Activities queries "Drug-related hepatic disorders-comprehensive search" (DRHD-CS) and "Drug-related hepatic disorders-severe events only" (DRHD-SEO).

RESULTS

We found several signals for drug-associated liver injury including signals for severe events: 17 of 30 antipsychotics were associated with DRHD-CS and 10 of 30 antipsychotics with DRHD-SEO. Amisulpride, fluphenazine, levomepromazine, loxapine, olanzapine, perazine, perphenazine, pipamperone, sulpiride, and thioridazine were associated with both, DRHD-CS and DRHD-SEO. No association with fatal outcomes was detected.

CONCLUSIONS

Several common antipsychotics are associated with hepatotoxicity, partly also with severe hepatotoxicity. Our data do not allow to account for patient-related risk factors for drug-associated liver injury. This should be addressed in further studies.

Liver Transplantation and the Use of Metamizole to Treat Drug-induced Liver Injury

Metamizole, or dipyrone, is a frequently prescribed analgetic drug that can cause drug-induced liver injury (DILI). Still, there are only a few metamizole-associated DILI cases (n = 61, including our study) described in the literature. So far liver transplantation has been reported in 6 patients with metamizole-induced acute liver failure. In 2020, a German group described a bigger cohort (n = 23) of metamizole-related DILI. Shortly thereafter, this issue gained wider attention as the German Federal Institute for Drugs and Medical Devices published a Direct Healthcare Professional Communication, emphasizing DILI as a potential adverse event caused by metamizole. We herein report 2 patients that were admitted to our liver transplant center due to acute liver failure (ALF) in April and May 2021. Both patients reported intake of metamizole as pain medication over a few weeks. After ruling out alternative reasons for ALF and fulfilling the King's College criteria both patients received emergency liver transplantations in our center. Pathology assessment of both explants were consistent with metamizole-associated DILI. As illustrated by our 2 cases of metamizole-induced liver failure with subsequent liver transplantation, this rare but presumably often overlooked adverse drug effect of metamizole should be considered as differential diagnosis in cases of cryptogenic liver failure.

Inconsistencies and Ambiguities in Liver-Disease-Related Contraindications-A Systematic Analysis of SmPCs/PI of Major Drug Markets

Liver disease is a common condition worldwide that can cause alterations in drug disposition and susceptibility to drug toxicities, with increased risk of adverse drug reactions. European Summaries of Product Characteristics (SmPCs) and United States Prescribing Information (US PI) should therefore be comprehensible to prescribers regarding their liver-associated contraindications to ensure safe prescribing. This study aimed to evaluate the ambiguity of terminology used in communicating liver-associated absolute contraindications in SmPCs/PI of commonly prescribed drugs in four major drug markets (Germany, Switzerland, the United Kingdom, and the United States) by assigning wordings to different categories and analyzing their clinical comprehensibility. For US PI, 79% did not contain liver-related contraindications, compared to 2, 13, and 6% of German, Swiss, and British SmPCs, respectively. Study findings indicate that out of 228 examined SmPCs/PI containing liver-related contraindications, 77, 79, 76, and 52% contained unclear wording in the German, Swiss, British, and American drug market, respectively. Only 40% (German), 52% (Swiss), 39% (British), and 29% (American) of SmPCs/PI included terms with explicit wording. Including more precise statements in SmPCs/PI based on laboratory parameters (such as albumin) or scores (e.g., the Child–Pugh score) to objectify the severity of liver disease may improve the clarity of SmPCs/PI and the safety of drug prescription.

Drug-induced liver injury at a tertiary care centre in Germany: Model for end-stage liver disease is the best predictor of outcome

BACKGROUND & AIMS

Agents most frequently inducing idiosyncratic drug-induced liver injury (DILI) differ between countries worldwide. Besides, there is no consistent data on the best model predicting mortality or the need for liver transplantation in DILI. We here analysed the DILI cohort of our centre with regard to causative drugs and clinical outcome.

METHODS

A retrospective analysis of 157 consecutive severe DILI patients presenting to our tertiary care centre in Hamburg, Germany, from 2008 to 2018, was performed.

RESULTS

The most frequent putatively causative drugs were phenprocoumon (n = 21), metamizole (n = 17) and flupirtine (n = 6). The mean values of ALT, bilirubin and Model for End-stage Liver Disease (MELD) score at the time of hospitalisation were 1201 U/L (SD: 1169 U/L), 6.8 mg/dL (SD: 7 mg/dL) and 17 (SD: 8). About 71% of all cases were treated with steroids or steroids combined with n-acetylcysteine. About 12.1% of all DILI cases had a poor outcome (liver transplantation and/or death). At the time of admission, MELD score performed better than Hy's law, the ratio (R) or the new ratio (nR) on their own or combined with bilirubin, regarding sensitivity or specificity for poor outcome. MELD score had a c-statistic of 0.847 (95% CI: 0.731-0.964). Furthermore, the cut-off of 18 MELD points had a sensitivity of 88% and a specificity of 72% for poor outcome.

CONCLUSION

Phenprocoumon and metamizole are frequent causative drugs for DILI in Germany. In comparison to other prognostic scores, MELD score ≥18 at the time of admission performed best in our cohort for the prediction of poor outcome in DILI.

Is There an Increased Risk of Hepatotoxicity with Metamizole? A Comparative Cohort Study in Incident Users

INTRODUCTION

The analgesic metamizole, which has been withdrawn from the market in several countries due to the risk of agranulocytosis but is still available on the market in Germany and some other countries, has been associated with liver injury in published case reports; however, epidemiological studies on the risk of liver injury are limited.

OBJECTIVE

The aim of this study was to compare the risk of liver injury up to 270 days after the first start of treatment with metamizole with the corresponding risk in patients starting treatment with paracetamol, using a retrospective cohort incident user design.

METHODS

The first prescription for either metamizole or paracetamol in the Intercontinental Medical Statistics (IMS)^® Disease Analyzer Germany database during the study period (2009-2018) was identified in patients with at least 365 days of observation and no prior diagnosis of liver events, cancer or HIV, or treatment within the last 6 months with hepatotoxic drugs typically administered for chronic conditions. Each patient was followed for specific liver events for 90 days after the prescription. In case of a new prescription within 90 days, a new 90-day observation period started, up to a maximum of 270 days. Cox regression was used to compare the risk of liver injury in the two groups.

RESULTS

Metamizole was associated with a higher risk of liver injury compared with paracetamol (adjusted hazard ratio 1.69, 95% confidence interval 1.46-1.97). Sensitivity analyses were performed to evaluate the robustness of these findings. In all the sensitivity analyses, metamizole was still associated with a higher risk of liver injury, including an analysis where naproxen was used as a comparator instead of paracetamol.

CONCLUSIONS

Results from this study support previous studies suggesting that metamizole is associated with a significant risk of liver injury. Nevertheless, a possible impact of residual confounding cannot be excluded.

Severe drug-induced liver injury in patients under treatment with antipsychotic drugs: Data from the AMSP study

OBJECTIVES

Drug-induced liver injury (DILI) has been associated with various antipsychotic drugs (APDs). Comparative studies between individual APDs are largely not available.

METHODS

Antipsychotic drug utilisation data and reports of severe antipsychotic DILI were assessed by using data from an observational pharmacovigilance programme-Arzneimittelsicherheit in der Psychiatrie (AMSP)-during the period 1993-2016.

RESULTS

Of the 333,175 patients treated with APDs, a total of 246 (0.07%) events of severe DILI were identified. Phenothiazines were associated with significantly higher rates of severe DILI (0.03%, 95% CI = 0.02-0.04) than thioxanthenes (0.01%, 95% CI = 0.00-0.02) or butyrophenones (0.01%, 95% CI = 0.00-0.01). Among individual drugs, olanzapine (0.12%, 95% CI = 0.10-0.16), perazine (0.09%, 95% CI = 0.05-0.15) and clozapine (0.09%, 95% CI = 0.10-0.12 ranked highest. In 78 cases (31.7%), combination therapies with antipsychotic and antidepressant drugs or with two or more APDs were considered responsible. Male sex and a diagnosis of mania were associated with significantly higher rates of severe DILI while older patients (≥65 years old) were significantly less often affected.

CONCLUSIONS

In the present analysis of a representative psychiatric inpatient cohort, olanzapine, perazine, and clozapine were the most common individual APDs associated with severe DILI.

Prevalence and clinical characteristics of antibiotics associated drug induced liver injury

Background

The use of antibiotics increases recently. Accordingly, the incidence of antibiotics associated with drug induced liver injury (DILI) also increases. The purpose of this study is to evaluate the proportion and the clinical characteristics of antibiotic associated with DILI.

Methods

This study is a retrospective study of analyzed adult patients who were referred to the department of hepatology for the elevation of liver function tests and the frequency of elevated liver enzyme of patients with prescribed antibiotics during the same period at outpatient setting as a validation set.

Results

Antibiotics associated with DILI (64.0%) are the most common reason agent among consulting to hepatology department. Rheumatoid arthritis related drugs (11.0%), health supplements (5.0%), herbal medicines (4.0%), anti-viral drugs, anti-inflammatory analgesics/acetaminophen and lipid-lowering agents (3.0%) were next common causative drug for DILI in inpatients setting (training set). The frequency of antibiotics associated with DILI was high in order of flomoxef, cetrazole, ceftriaxone, vancomycin, piperacillin/tazobactam and amoxicillin/clavulanate. In the same period, 32% of the patients who prescribed flomoxef showed elevated liver enzyme levels above the upper normal limit. The prevalence of flomoxef induced DILI (>3 folds of ALT) was 13% and liver enzyme levels were five times higher than upper normal limits in 5% of flomoxef groups. Hypertension or diabetes was the risk factor of flomoxef associated with DILI.

Conclusions

The Prevalence of antibiotics associated with DILI was 2-14%. Co-morbidity with diabetes and hypertension was the risk factor of flomoxef associated with DILI.

HMGB1: An overview of its roles in the pathogenesis of liver disease

High-mobility group box 1 (HMGB1) is an abundant architectural chromosomal protein that has multiple biologic functions: gene transcription, DNA replication, DNA-damage repair, and cell signaling for inflammation. HMGB1 can be released passively by necrotic cells or secreted actively by activated immune cells into the extracellular milieu after injury. Extracellular HMGB1 acts as a damage-associated molecular pattern to initiate the innate inflammatory response to infection and injury by communicating with neighboring cells through binding to specific cell-surface receptors, including Toll-like receptors (TLRs) and the receptor for advanced glycation end products (RAGE). Numerous studies have suggested HMGB1 to act as a key protein mediating the pathogenesis of chronic and acute liver diseases, including nonalcoholic fatty liver disease, hepatocellular carcinoma, and hepatic ischemia/reperfusion injury. Here, we provide a detailed review that focuses on the role of HMGB1 and HMGB1-mediated inflammatory signaling pathways in the pathogenesis of liver diseases.

Drug Induced Liver Injury in Geriatric Patients Detected by a Two-Hospital Prospective Pharmacovigilance Program: A Comprehensive Analysis Using the Roussel Uclaf Causality Assessment Method

Background/aim: A prospective evaluation of drug-induced liver injury (DILI) in two tertiary hospitals was conducted through a pharmacovigilance program from laboratory signals at hospital (PPLSH) to determine the principal characteristics of DILI in patients older than 65 years, a growing age group worldwide, which is underrepresented in the literature on DILI.

Methods: All DILI in patients older than 65 years detected by PPLSH in two hospitals were followed up for 8 years in the La Paz Hospital and 2 years in the Getafe Hospital. A descriptive analysis was conducted that determined the causality of DILI and suspected drugs, the incidence of DILI morbidities, DILI characteristics, laboratory patterns, evolution and outcomes.

Results: 458 DILI cases in 441 patients were identified, 31.0% resulting in hospitalisation and 69.0% developing during hospitalisation. The mean age was 76.61 years old (SD, 7.9), and 54.4% were women. The DILI incidence was 76.33/10,000 admissions (95%CI 60.78–95.13). Polypharmacy (taking >4 drugs) was present in 86.84% of patients, 39.68% of whom took >10 drugs. The hepatocellular phenotype was the most frequent type of DILI (53.29%), a higher proportion (65%) had a mild severity index, and, in 55.2% of the evaluated drugs the RUCAM indicated that the causal relationship was highly probable. The most frequently employed drugs were paracetamol (50-cases), amoxicillin-clavulanate (42-cases) and atorvastatin (37-cases). The incidence rate of in-hospital DILI per 10,000 DDDs was highest for piperacillin-tazobactam (66.96/10,000 DDDs). A higher risk of in-hospital DILI was associated with the therapeutic chemical group-J (antiinfectives for systemic use) (OR, 2.65; 95%CI 1.58–4.46) and group-N (central nervous system drugs) (OR, 2.33; 95%CI 1.26–4.31). The patients taking >4 medications presented higher maximum creatinine level (OR, 2.01; 95%CI 1.28–3.15), and the patients taking >10 medications had a higher use of group J drugs (OR, 2.08; 95%IC 1.31–3.32).

Conclusion: The incidence rate of DILI in the patients older than 65 years was higher than expected. DILI in elderly patients is mild, has a good outcome, has a hepatocellular pattern, develops during hospitalisation, and prolongs the hospital stay. Knowing the DILI incidence and explanatory factors will help improve the therapy of the elderly population.

Hepatic adverse drug reactions in Malaysia: An 18-year review of the national centralized reporting system

PURPOSE

To determine the incidence, demographic profile, background of reporters, causative agents, severity and clinical outcomes of hepatic adverse drug reaction (ADR) reports in Malaysia using the national ADR reporting database.

METHODS

The ADR reports recorded between 2000 and 2017 were retrospectively analysed to identify hepatic ADR reports. The trend and characteristics of hepatic ADR cases were described. Multivariate disproportionality analysis of the causative agents was performed to generate signals of hepatic ADRs.

RESULTS

A total of 2090 hepatic ADRs (1.77% of all ADRs) were reported with mortality rate of 12.7% among cases with known clinical outcomes. The incidence of hepatic ADR reporting in Malaysia increased significantly over 18 years from 0.26 to 9.45 per million population (P < .001). Antituberculosis drugs (n = 268, 12.82%) was the most common suspected class of causative agents with a reporting odds ratio (ROR) and 95% CI of 8.39 (7.26-9.70), followed by traditional/complementary medicines or herbal/dietary supplements (TCM/HDS) (n = 235, 11.24%, ROR 3.26 [2.84-3.75]), systemic antibacterials (n = 159, 7.61%, ROR 2.65 [2.25-3.13]), lipid modifying agents (n = 142, 6.79%, ROR 2.21 [1.86-2.63]) and amiodarone (n = 137, 6.56%, ROR 35.25 [28.40-43.75]). Most (72.9%) of the TCM/HDS were not registered with the authorities.

CONCLUSIONS

Hepatic ADR cases have increased significantly in Malaysia, with antituberculosis drugs, systemic antibacterials, and TCM/HDS being the most common causative agents reported. Most TCM/HDS reported to be associated with hepatic ADR were not registered with the authorities.

Worldwide Use of RUCAM for Causality Assessment in 81,856 Idiosyncratic DILI and 14,029 HILI Cases Published 1993-Mid 2020: A Comprehensive Analysis

Background: A large number of idiosyncratic drug induced liver injury (iDILI) and herb induced liver injury(HILI) cases of variable quality has been published but some are a matter of concern if the cases were not evaluated for causality using a robust causality assessment method (CAM) such as RUCAM (Roussel Uclaf Causality Assessment Method) as diagnostiinjuryc algorithm. The purpose of this analysis was to evaluate the worldwide use of RUCAM in iDILI and HILI cases. Methods: The PubMed database (1993-30 June 2020) was searched for articles by using the following key terms: Roussel Uclaf Causality Assessment Method; RUCAM; Idiosyncratic drug induced liver injury; iDILI; Herb induced liver injury; HILI. Results: Considering reports published worldwide since 1993, our analysis showed the use of RUCAM for causality assessment in 95,885 cases of liver injury including 81,856 cases of idiosyncratic DILI and 14,029 cases of HILI. Among the top countries providing RUCAM based DILI cases were, in decreasing order, China, the US, Germany, Korea, and Italy, with China, Korea, Germany, India, and the US as the top countries for HILI. Conclusion: Since 1993 RUCAM is certainly the most widely used method to assess causality in IDILI and HILI. This should encourage practitioner, experts, and regulatory agencies to use it in order to reinforce their diagnosis and to take sound decisions.

Switching from clozapine to paliperidone palmitate-3-monthly improved obesity, hyperglycemia and dyslipidemia lowering antipsychotic dose equivalents in a treatment-resistant schizophrenia cohort

Clozapine, an antipsychotic developed in 1958, is considered the gold standard and the treatment of choice in treatment-resistant schizophrenia despite its side effects and despite 40-70% of these patients not responding to clozapine. In the last decade, new antipsychotics, such as paliperidone palmitate (PP), have emerged as well as its long acting-injectable (LAI) formulations, available as PP-1-monthly (PP1M) and the newest PP-3-montlhy (PP3M). Despite paliperidone having shown a similar efficacy as others antipsychotics for the treatment of schizophrenia, and that PP3M has been shown to reduce relapses compared to oral formulations, no study has been carried out in treatment-resistant schizophrenia. The aim of our study was to carry out an exploratory evaluation of endocrine and hepatic profiles as well as the concomitant treatments associated to PP3M vs. clozapine, the gold standard, in patients with treatment-resistant schizophrenia. We designed a retrospective study. A total number of 33 patients previously diagnosed as schizophrenics treatment-resistant, who were prescribed clozapine followed by PP1M and PP3M when available, were selected. Demographic data, BMI, hepatic enzymes (glutamic oxaloacetic transaminase, glutamate-pyruvate transaminase and gamma-glutamyl transferase (GGT)], thyroid function (thyroid stimulating hormone), blood platelets and both white and red blood cells as well as the use of concomitant antipsychotics, benzodiazepines and biperiden were compared under treatment with clozapine and PP3M. Antipsychotics and benzodiazepines dosages were compared using by the defined daily dose (DDD) method and haloperidol or diazepam dose equivalents. All statistical analyses were performed using the paired Student t-test for repeated measures. Our data showed that patients under treatment with PP3M showed a significant decrease in BMI (P < 0.01), glucose (P < 0.01), cholesterol (P < 0.05) and triglycerides (P < 0.01) when compared with basal values under treatment with clozapine. Hepatic cholestasis enzyme, GGT, were significantly elevated (P < 0.05) under treatment with clozapine when compared to PP3M. Switching clozapine to PP3M led to a significant lower pharmacological exposure to antipsychotics, by both the DDD (P < 0.05) and haloperidol dose equivalents (P < 0.001) methods without increasing the dose of benzodiazepines while biperiden was more used under PP3M. Finally, antipsychotic monotherapy was higher and less polypharmacy was used with PP3M. In conclusion, our findings suggest that switching clozapine to PP3M improved endocrine and hepatic profile with a lower total exposure to antipsychotics. More studies are needed to truly establish the role of PP3M in treatment-resistant schizophrenia and should be compared against clozapine by using clinical trials.

Metamizole: An underrated agent causing severe idiosyncratic drug-induced liver injury

Aims

Drug‐induced liver injury (DILI) is a heterogenous entity leading to liver damage. We have analysed the frequency, biochemical and histological patterns and clinical courses of DILI cases due to metamizole at our tertiary care centre in Hamburg, Germany.

Methods

Consecutive patients with DILI who presented to our clinic were analysed retrospectively. Causes of acute hepatitis other than DILI were excluded.

Results

In total, 154 DILI cases were admitted to our centre from 2008 to 2017. After phenprocoumon, metamizole was the second most frequent putative agent causing DILI (23 of all 154 DILI cases, 14,9%). The biochemical pattern on admission of metamizole‐induced DILI cases was hepatocellular with median levels of alanine transaminase (779 U/L, 64–3532 U/L) by far exceeding median alkaline phosphatase levels (131 U/L, 42–578 U/L). In 17 of the 23 cases (74%) liver biopsy was performed. Moderate to severe inflammatory histological activity and severe centrilobular necrosis (>30%) was present in 76.5 and 35.3%, respectively. Metamizole was involved in 2 DILI cases progressing to acute liver failure, then receiving liver transplantation and still alive at time of assessment. Our data were supported by re‐exposure in 4 patients. Furthermore, a database search for metamizole‐induced liver injury in the European Medicines Agency's database identified about 300 reports on suspected metamizole‐induced DILI in Europe.

Conclusion

Elevation of liver enzymes or acute liver failure are not mentioned in the German drug label of metamizole as potential side effects. Our study reveals that in Germany and Europe, metamizole is a frequent and underrated agent causing DILI.

Analysis of Hepatobiliary Disorder Reports Associated With the Use of Herbal Medicines in the Global Suspected ADR Database Vigibase

Introduction: Use of herbal medicines (HMs) is widespread across the world, with many people relying on HMs for their primary healthcare or using HMs in the context of a healthy life style. HMs originate from plant material and, as such, are often seen as "natural" and believed to be (relatively) safe by patients. Hepatobiliary disorders have been associated with numerous HMs. Aim: This paper aims to analyze reporting patterns for hepatobiliary disorders associated with HMs use from reports submitted to the WHO global database of individual case safety reports (ICSRs) VigiBase. Methods: A data extraction in VigiBase, the WHO international database of ICSR reports, was performed by the Uppsala Monitoring Centre on 2019-01-16. The dataset contained all ICSRs where an HM was identified with the UMC-assigned ATC code "V90: unspecified herbal and traditional medicine" and where the HM was classified as being either the suspected drug or an interacting drug, and containing at least one adverse reaction in the MedDRA® System Organ Class (SOC) Hepatobiliary Disorders (HBD). Descriptive analyses in Excel 2013® were used to determine general characteristics of the reports in the broad data set, including total number of reports, reporting country and patient characteristics. For single suspect herbal reports, reports categorized as "serious" according to CIOMS criteria (CIOMS), 2001) were extracted. Results: In total, 2,483 reports describing with at least one ADR in the SOC HBD were extracted from VigiBase. In total, 780 (31.4%) reports concern only one suspect HM. However, for 188 reports of these reports (24.1%), the single suspect herbal preparation contains more than one herbal ingredient. The 592 reports for single suspect herbal preparations described a total of 764 ADRs in the SOC HBD. Jaundice was the most reported ADR for these reports. Conclusion: Almost 2,500 reports for HMs and with at least one ADR coded to the MedDRA® SOC HBD were retrieved from VigiBase. Of the HBD SOC HM reports, around 25% concerned a single herbal species as the suspect "drug." Substantial issues with coding of the suspect herbal drugs were found. In-depth causality assessment of the cases is needed to draw conclusions on the strength of the relationships.

Amiodarone use and the risk of acute pancreatitis: Influence of different exposure definitions

Purpose

The antiarrhythmic drug amiodarone has a long half‐life of 60 days, which is often ignored in observational studies. This study aimed to investigate the impact of different exposure definitions on the association between amiodarone use and the risk of acute pancreatitis.

Method

Using data from the Dutch PHARMO Database Network, incident amiodarone users were compared to incident users of a different type of antiarrhythmic drug. Eighteen different definitions were applied to define amiodarone exposure, including dichotomized, continuous and categorized cumulative definitions with lagged effects to account for the half‐life of amiodarone. For each exposure definition, a Cox proportional hazards model was used to estimate the hazard ratio (HR) of hospitalization for acute pancreatitis.

Results

This study included 15,378 starters of amiodarone and 21,394 starters of other antiarrhythmic drugs. Adjusted HRs for acute pancreatitis ranged between 1.21−1.43 for dichotomized definitions of exposure to amiodarone, between 1.13‐1.22 for dose definitions (per DDD) and between 0.52‐1.72 for cumulative dose definitions, depending on the category. Accounting for lagged effects had little impact on estimated HRs.

Conclusions

This study demonstrates the relative insensitivity of the association between amiodarone and the risk of acute pancreatitis against a broad range of different exposure definitions. Accounting for possible lagged effects had little impact, possibly because treatment switching and discontinuation was uncommon in this population.

Non-Vitamin K Antagonist Oral Anticoagulants and Risk of Serious Liver Injury

BACKGROUND

Non-vitamin K antagonist oral anticoagulants (NOACs) are relatively new drugs used for stroke prevention in nonvalvular atrial fibrillation (NVAF). However, there are concerns that their use may be associated with hepatotoxic effects.

OBJECTIVES

The purpose of this study was to determine whether the use of NOACs is associated with an increased risk of serious liver injury compared with the use of vitamin K antagonists (VKAs) in NVAF patients with and without prior liver disease.

METHODS

Using the administrative databases of the Canadian province of Quebec's health insurances, the authors conducted a cohort study among patients newly diagnosed with NVAF between January 2011 and December 2014. Adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of serious liver injury (defined as either a hospitalization or related death) were estimated using time-dependent Cox proportional hazards models, comparing current use of NOACs to current use of VKAs separately among patients with or without prior liver disease.

RESULTS

The cohort comprised 51,887 patients, including 3,778 with prior liver disease. During 68,739 person-years of follow-up, 585 patients experienced a serious liver injury. Compared with current use of VKAs, current use of NOACs was not associated with an increased risk of serious liver injury in patients without or with prior liver disease (adjusted HR: 0.99; 95% CI: 0.68 to 1.45; and adjusted HR: 0.68; 95% CI: 0.33 to 1.37, respectively).

CONCLUSIONS

Compared with VKAs, NOACs were not associated with an increased risk of serious liver injury irrespective of baseline liver status. Overall, these results provide reassurance regarding the hepatic safety of NOACs.

Roussel Uclaf Causality Assessment Method for Drug-Induced Liver Injury: Present and Future

Among the causality assessment methods used for the diagnosis of drug-induced liver injury (DILI), Roussel Uclaf Causality Assessment Method (RUCAM) remains the most widely used not only for individual cases but also for prospective and retrospective studies worldwide. This first place is justified by the characteristics of the method such as precise definition and classification of the liver injury, which determines the right scale in the scoring system, precise definition of the seven criteria, and the validation approach based on cases with positive rechallenge. RUCAM is used not only for any types of drugs but also for herbal medicines causing herb-induced liver injury, (HILI) and dietary supplements. In 2016, the updated RUCAM provided further specifications of criteria and instructions to improve interobserver variability. Although this method was criticized for criteria such as the age and alcohol consumption, recent consensus meeting of experts has recognized their value and recommended their incorporation into any method. While early studies searching for DILI in large databases especially in electronic medical records were based on codes of diseases or natural language without causality assessment, the recommendation is now to include RUCAM in the search for DILI/HILI. There are still studies on DILI detection or the identification of biomarkers that take into consideration the cases assessed as “possible,” although it is well known that these cases reduce the strength of the association between the cases and the offending compound or the new biomarker to be validated. Attempts to build electronic RUCAM or automatized application of this method were successful despite some weaknesses to be corrected. In the future, more reflections are needed on an expert system to standardize the exclusion of alternative causes according to the clinical context. Education and training on RUCAM should be encouraged to improve the results of the studies and the day-to-day work in pharmacovigilance departments in companies or in regulatory agencies. It is also expected to improve RUCAM with biomarkers or other criteria provided that the validation process replaces expert opinion by robust standards such as those used for the original method.

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.

Systematic review of published data on herb induced liver injury

ETHNOPHARMACOLOGICAL RELEVANCE

Herbal products have been widely used as a means of ethnomedicine worldwide. Recently, the potential hepatotoxicity of herbs has become a medical issue but comprehensive studies are limited.

AIM OF THE STUDY

This study aims to determine the clinical features of herb induced liver injury (HILI) including its constituent ratio among liver injury case cohorts that included both HILI and drug induced liver injury (DILI).

MATERIALS AND METHODS

A systematic review was conducted using a literature search for DILI/HILI in seven electric databases including PubMed, Cochrane and Embase. We analyzed the DILI/HILI cases and clinical characteristics in terms of herbs, conventional drugs, concomitant, or others.

RESULTS

Thirty-one studies met the necessary criteria and included 9 prospective and 22 retrospective studies. Among total number of overall DILI/HILI cases (7511, male 2819, female 3669 and unknown 1023), 25.0% (1874 cases) were implicated in herbs. HILI was relatively higher in females (69.8% vs. 30.2% male), compared to conventional drugs (57.3% female vs. 42.7% male, p < 0.01), while it was prone to induce hepatocellular injury (hepatocellular 78.8%, cholestatic 8.9%, mixed type 12.3%), contrary to conventional drugs (hepatocellular 56.7% vs. cholestatic 22.1% vs. mixed 21.2%), respectively (p < 0.01). The main herbs causing HILI included Polygonum multiflorum, Psoralea corylifolia, Corydalis yanhusuo, and Rheum officinale.

CONCLUSIONS

This review created the comparative and comprehensive feature of hepatotoxicity by herbal products, which provides reference data for the clinical applications and establishing pharmacovigilance system of herbs.

Risk of Acute Liver Injury in Agomelatine and Other Antidepressant Users in Four European Countries: A Cohort and Nested Case-Control Study Using Automated Health Data Sources

BACKGROUND

Agomelatine is a melatonin receptor agonist and serotonin 5-HT2C receptor antagonist indicated for depression in adults. Hepatotoxic reactions like acute liver injury (ALI) are an identified risk in the European risk management plan for agomelatine. Hepatotoxic reactions have been reported for other antidepressants, but population studies quantifying these risks are scarce. Antidepressants are widely prescribed, and users often have risk factors for ALI (e.g. metabolic syndrome).

OBJECTIVE

The goal was to estimate the risk of ALI associated with agomelatine and other antidepressants (fluoxetine, paroxetine, sertraline, escitalopram, mirtazapine, venlafaxine, duloxetine, and amitriptyline) when compared with citalopram in routine clinical practice.

METHOD

A nested case-control study was conducted using data sources in Denmark, Germany, Spain, and Sweden (study period 2009-2014). Three ALI endpoints were defined using International Classification of Diseases (ICD) codes: primary (specific codes) and secondary (all codes) endpoints used only hospital discharge codes; the tertiary endpoint included both inpatient and outpatient settings (all codes). Validation of endpoints was implemented. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for current use were estimated for each data source and combined.

RESULTS

We evaluated 3,238,495 new antidepressant and 74,440 agomelatine users. For the primary endpoint, the OR for agomelatine versus citalopram was 0.48 (CI 0.13-1.71). Results were also < 1 when no exclusion criteria were applied (OR 0.37; CI 0.19-0.74), when all exclusion criteria except alcohol and drug abuse were applied (OR 0.47; CI 0.20-1.07), and for the secondary (OR 0.40; CI 0.05-3.11) and tertiary (OR 0.79; CI 0.50-1.25) endpoints. Regarding other antidepressants versus citalopram, most OR point estimates were also below one, although with varying widths of the 95% CIs. The result of the tertiary endpoint and the sensitivity analyses of the primary endpoint were the most precise.

CONCLUSION

In this study, using citalopram as a comparator, agomelatine was not associated with an increased risk of ALI hospitalisation. The results for agomelatine should be interpreted in the context of the European risk minimisation measures in place. Those measures may have induced selective prescribing and could explain the lower risk of ALI for agomelatine when compared with citalopram. Most other antidepressants evaluated had ORs suggesting a lower risk than citalopram, but additional studies are required to confirm or refute these results.

How to replace the lost keys? Strategies toward safer KV7 channel openers

The highly structurally similar drugs flupirtine and retigabine have been regarded as safe and effective for many years but lately they turned out to exert intolerable side effects. While the twin molecules share the mode of action, both stabilize the open state of voltage-gated potassium channels, the form and severity of adverse effects is different. The analgesic flupirtine caused drug-induced liver injury in rare but fatal cases, whereas prolonged use of the antiepileptic retigabine led to blue tissue discoloration. Because the adverse effects seem unrelated to the mode of action, it is likely, that both drugs that occupied important therapeutic niches, could be replaced. Reasons for the clinically relevant toxicity will be clarified and future substitutes for these drugs presented in this review.

Roussel Uclaf Causality Assessment Method for Drug-Induced Liver Injury: Present and Future

Among the causality assessment methods used for the diagnosis of drug-induced liver injury (DILI), Roussel Uclaf Causality Assessment Method (RUCAM) remains the most widely used not only for individual cases but also for prospective and retrospective studies worldwide. This first place is justified by the characteristics of the method such as precise definition and classification of the liver injury, which determines the right scale in the scoring system, precise definition of the seven criteria, and the validation approach based on cases with positive rechallenge. RUCAM is used not only for any types of drugs but also for herbal medicines causing herb-induced liver injury, (HILI) and dietary supplements. In 2016, the updated RUCAM provided further specifications of criteria and instructions to improve interobserver variability. Although this method was criticized for criteria such as the age and alcohol consumption, recent consensus meeting of experts has recognized their value and recommended their incorporation into any method. While early studies searching for DILI in large databases especially in electronic medical records were based on codes of diseases or natural language without causality assessment, the recommendation is now to include RUCAM in the search for DILI/HILI. There are still studies on DILI detection or the identification of biomarkers that take into consideration the cases assessed as "possible," although it is well known that these cases reduce the strength of the association between the cases and the offending compound or the new biomarker to be validated. Attempts to build electronic RUCAM or automatized application of this method were successful despite some weaknesses to be corrected. In the future, more reflections are needed on an expert system to standardize the exclusion of alternative causes according to the clinical context. Education and training on RUCAM should be encouraged to improve the results of the studies and the day-to-day work in pharmacovigilance departments in companies or in regulatory agencies. It is also expected to improve RUCAM with biomarkers or other criteria provided that the validation process replaces expert opinion by robust standards such as those used for the original method.

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.

Top-ranking drugs out of 3312 drug-induced liver injury cases evaluated by the Roussel Uclaf Causality Assessment Method

INTRODUCTION

A list presenting a valid ranking of drugs most commonly implicated is hardly to be found. Areas covered: Published cases of drug-induced liver injury (DILI) with verified causality using RUCAM (Roussel Uclaf Causality Assessment Method) were used for a ranking of drugs most commonly implicated in causing DILI. Expert opinion: RUCAM-based DILI cases were retrieved from 15 reports published by six international databases of DILI registries and three large medical centers, which provided 3312 cases. Overall 48 drugs with the highest number of DILI cases were listed. Among the top 10 ranking drugs implicated in causing DILI were, in decreasing order: amoxicillin-clavulanate, flucloxacilllin, atorvastatin, disulfiram, diclofenac, simvastatin, carbamazepine, ibuprofen, erythromycin, and anabolic steroids as bodybuilding agents. For these 10 drugs, respective DILI case numbers were highest for Amoxicillin-clavulanate (n=333) and lowest for anabolic steroids (n=26). The author classifies the databases of national DILI registries and large medical centers as best sources of drugs implicated in DILI. Presently discouraged is the use of the LiverTox website because many cases were derived from published cases of poor quality and could previously not be classified as DILI, calling for the inclusion of DILI cases with established causality by the updated RUCAM.

Flupirtine drug-induced liver injury in a patient developing acute liver failure

A patient is admitted with complaints of recent onset nausea, discomfort, jaundice and blood tests that reveal severe hepatitis. At the time, she had been taking medication with Hypericum perforatum (St John's wort) for 6 months, and 6 weeks before this event, she took flupirtine maleate. A few days after being admitted, she developed encephalopathy progressing to acute liver failure (ALF) requiring unsuccessful liver transplantation. The patient was ultimately diagnosed with drug-induced liver injury (DILI). In this context, while H. perforatum could interfere with other medication or trigger DILI itself, flupirtine appears to have triggered the DILI, given its liver toxicity capacity. DILI is one of the major ALF causes and can jeopardise patient's life. Accordingly, all efforts to reduce medication potentially hazardous to the liver are recommended.

Antipsychotic Drugs and Liver Injury

In October 2015, the drug-induced liver diseases group of the Chinese Society of Hepatology drafted and published the first Diagnosis and Treatment Guidelines on Drug-induced Liver Injury in China, giving suggestions on the diagnosis and treatment of drug-induced liver injury (DILI). As a psychiatrist, I have found that in clinical practice both typical and new antipsychotic drugs can induce liver injury to varying degrees. Therefore, it is necessary to quickly and accurately determine the cause of liver injury and the type and severity of injury and establish a solution. This article reviewed relevant literature including the common pathogenesis and clinical manifestations of drug-induced liver injury caused by antipsychotic drugs, laboratory tests, diagnostic criteria and classification, and clinical management strategies. This paper also includes a summary and a perspective on liver injury caused by antipsychotic drugs.

Adaptive unfolded protein response promotes cell survival in rifampicin-treated L02 cells

An important concept in drug-induced liver injury (DILI) is adaptation, which means the injury reverses with the continuation of the drug. The mechanism of adaption of drugs remains enigmatic, adaptive unfolded protein response (UPR) is possibly involved. We once observed adaptation phenomenon of rifampicin (RFP) in animal models, in this study, we investigate the effects of RFP on adaptive UPR in L02 cells, and after inhibiting UPR by using 4-phenylbutyrate (4-PBA), the change of cell viability and cell apoptosis in RFP-treated cells. We found that with the concentration of RFP increased and the treatment time was prolonged, the glucose-regulated protein 78 (GRP78), a hallmark of the UPR, was upregulated, and was dose- and time-dependent. RFP also activates the p-eukaryotic initiation factor 2α (eIF2α) protein expression. 4-PBA decreased GRP78 and p-eIF2α protein expression levels. Moreover, FCA showed that cell apoptosis rate obviously increased, and MTT assay showed that cell survival rate obviously decreased, this indicates that after inhibiting the UPR, the cell damage increased, which shows that the UPR is an adaptation mechanism to protect cells against injury induced by RFP. This also proves that when the degree of UPR induced by RFP is relatively mild, adaptive UPR is helpful for cell survival.

Drug-Induced Liver Injury: An Institutional Case Series and Review of Literature

Drug-induced liver injury (DILI) is the most common cause of acute liver failure in the USA. DILI can be broadly classified as Intrinsic and Idiosyncratic. Identifying predictors and at-risk patients are challenging but can have a substantial clinical implication. This case report series demonstrates the importance of valproic acid, fluconazole, and amiodarone as potential hepatoxic agents of drug-induced liver injury leading to acute hepatic failure. The causality in all cases was established by Roussel Uclaf Causality Assessment Method/Council for International Organizations of Medical Sciences score and Naranjo Algorithm. Obesity, hypo-perfusion state, and concurrent hepatotoxic agent might identify at-risk patients. Further studies are required to understand the risk factors.

Hepatic Safety of Atypical Antipsychotics: Current Evidence and Future Directions

The newer atypical antipsychotic agents (AAPs) represent an attractive therapeutic option for a wide range of psychotic disorders, including schizophrenia and bipolar mania, because of the reduced risk of disabling extrapyramidal symptoms. However, their growing use has raised questions about their tolerability over the endocrine, metabolic, and cardiovascular axes. Indeed, atypical antipsychotic drugs are associated, to differing extents, with mild elevation of aminotransferases related to weight gain, AAP-induced metabolic syndrome, and nonalcoholic fatty liver disease. Although the hepatic safety of new AAPs seems improved over that of chlorpromazine, they can occasionally cause idiosyncratic liver injury with varying phenotypes and, rarely, lead to acute liver failure. However, AAPs are a group of heterogeneous, chemically unrelated compounds with distinct pharmacological and pharmacokinetic properties and substantially different safety profiles, which precludes the notion of a class effect for hepatotoxicity risk and highlights the need for an individualized therapeutic approach. We discuss the current evidence on the hepatotoxicity potential of AAPs, the emerging underlying mechanisms, and the limitations inherent to this group of drugs for both establishing a proper causality assessment and developing strategies for risk management.

Highlights of drug - and herb- induced liver injury in the literature from 2016: how best to translate new information into clinical practice?

INTRODUCTION

Over 1500 papers on drug-induced liver injury (DILI) and herb-induced liver injury (HILI) were published in 2016, many of which have the potential to impact clinical practice. Areas covered: Clinical studies and case series that lent themselves to new concepts in diagnosing, and treating DILI were selected for inclusion. Epidemiology of DILI in large prospective registries was highlighted. Causality assessment of drug hepatotoxicity remains challenging, as seen with cases of OxyELITE Pro (OEP). In 2016 updates to the Roussel Uclaf Causality Assessment Method (RUCAM) were published to aid in the accuracy of diagnosing DILI/HILI. New reports of established hepatotoxins were again discussed in 2016, including genetic risk factors for DILI with respect to antituberculous agents. Expert opinion: 2016 marked a turning point in how much credence should be placed in the current causality assessment for DILI/HILI cases. Many recognized hepatotoxins are backed by a relatively few number of literature reports. Danan and Teschke make a strong case that an updated RUCAM should remain the gold standard for diagnosing DILI/HILI going forward, although the role of expert opinion is often still needed in cases where RUCAM falls short. The field of chemoinformatics continues to evolve while we await a truly predictive and diagnostic DILI biomarker.

HLA-DRB1*16: 01-DQB1*05: 02 is a novel genetic risk factor for flupirtine-induced liver injury

OBJECTIVE

Flupirtine is a nonopioid analgesic with regulatory approval in a number of European countries. Because of the risk of serious liver injury, its use is now limited to short-term pain management. We aimed to identify genetic risk factors for flupirtine-related drug-induced liver injury (DILI) as these are unknown.

MATERIALS AND METHODS

Six flupirtine-related DILI patients from Germany were included in a genome-wide association study (GWAS) involving a further 614 European cases of DILI because of other drugs and 10,588 population controls. DILI was diagnosed by causality assessment and expert review. Human leucocyte antigen (HLA) and single nucleotide polymorphism genotypes were imputed from the GWAS data, with direct HLA typing performed on selected cases to validate HLA predictions. Four replication cases that were unavailable for the GWAS were genotyped by direct HLA typing, yielding an overall total of 10 flupirtine DILI cases.

RESULTS

In the six flupirtine DILI cases included in the GWAS, we found a significant enrichment of the DRB1*16:01-DQB1*05:02 haplotype compared with the controls (minor allele frequency cases 0.25 and minor allele frequency controls 0.013; P=1.4 × 10(-5)). We estimated an odds ratio for haplotype carriers of 18.7 (95% confidence interval 2.5-140.5, P=0.002) using population-specific HLA control data. The result was replicated in four additional cases, also with a haplotype frequency of 0.25. In the combined cohort (six GWAS plus four replication cases), the haplotype was also significant (odds ratio 18.7, 95% confidence interval 4.31-81.42, P=6.7 × 10(-5)).

CONCLUSION

We identified a novel HLA class II association for DILI, confirming the important contribution of HLA genotype towards the risk of DILI generally.

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.

Clinical characteristics of drug-induced liver injury and related risk factors

Drug-induced liver injury (DILI) is often undiagnosed or misdiagnosed clinically because of diagnostic difficulties caused by lack of laboratory-specific serological markers. In this study, we comprehensively assessed the clinical characteristics, laboratory indices, hepatotoxic drugs, risk factors and outcomes concerning DILI, and explored the similarities in mechanisms between Chinese and Western drug-induced DILI. Patients with a first diagnosis of DILI and a Roussel Uclaf Causality Assessment Method (RUCAM) score >3 points were enrolled for systematic retrospective study. Their clinical characteristics, clinical classification, risk factors, laboratory indices, hepatotoxic drugs and outcomes were analyzed. Cholestatic patients had the highest alkaline phosphatase (ALP) and prothrombin time activity (PTA) levels (P<0.05). Patients with medication time ≥30 days had significantly higher positive rate of autoantibodies than those with medication time <30 days. Odds ratio values for DILI-related factors such as hepatobiliary diseases, immune dysfunction, diabetes, hypertension, chronic alcohol consumption and age ≥45 years were 6.552, 6.130, 3.774, 2.801, 2.002 and 1.838, respectively. Pathogeneses of Chinese and Western drug-induced DILI may be substantially the same. DILI accompanied with autoantibody positivity may indicate severe liver injury outcome. Hepatobiliary diseases, diabetes and hypertension are likely to increase drug susceptibility, and more prone to cause liver injury.

Co(III)-Carbene Radical Approach to Substituted 1H-Indenes

A new strategy for the catalytic synthesis of substituted 1H-indenes via metalloradical activation of o-cinnamyl N-tosyl hydrazones is presented, taking advantage of the intrinsic reactivity of a Co(III) carbene radical intermediate. The reaction uses readily available starting materials and is operationally simple, thus representing a practical method for the construction of functionalized 1H-indene derivatives. The cheap and easy to prepare low spin cobalt(II) complex [Co(II)(MeTAA)] (MeTAA = tetramethyltetraaza[14]annulene) proved to be the most active catalyst among those investigated, which demonstrates catalytic carbene radical reactivity for a nonporphyrin cobalt(II) complex, and for the first time catalytic activity of [Co(II)(MeTAA)] in general. The methodology has been successfully applied to a broad range of substrates, producing 1H-indenes in good to excellent yields. The metallo-radical catalyzed indene synthesis in this paper represents a unique example of a net (formal) intramolecular carbene insertion reaction into a vinylic C(sp(2))-H bond, made possible by a controlled radical ring-closure process of the carbene radical intermediate involved. The mechanism was investigated computationally, and the results were confirmed by a series of supporting experimental reactions. Density functional theory calculations reveal a stepwise process involving activation of the diazo compound leading to formation of a Co(III)-carbene radical, followed by radical ring-closure to produce an indanyl/benzyl radical intermediate. Subsequent indene product elimination involving a 1,2-hydrogen transfer step regenerates the catalyst. Trapping experiments using 2,2,6,6-tetra-methylpiperidine-1-oxyl (TEMPO) radical or dibenzoylperoxide (DBPO) confirm the involvement of cobalt(III) carbene radical intermediates. Electron paramagnetic resonance spectroscopic spin-trapping experiments using phenyl N-tert-butylnitrone (PBN) reveal the radical nature of the reaction.

Risk of acute and serious liver injury associated to nimesulide and other NSAIDs: data from drug-induced liver injury case-control study in Italy

Aim

Drug‐induced liver injury is one of the most serious adverse drug reactions and the most frequent reason for restriction of indications or withdrawal of drugs. Some nonsteroidal anti‐inflammatory drugs (NSAIDs) were withdrawn from the market because of serious hepatotoxicity. We estimated the risk of acute and serious liver injury associated with the use of nimesulide and other NSAIDs, with a prevalence of use greater than or equal to 5%.

Methods

This is a multicentre case–control study carried out in nine Italian hospitals from October 2010 to January 2014. Cases were adults, with a diagnosis of acute liver injury. Controls presented acute clinical disorders not related to chronic conditions, not involving the liver. Adjusted odds ratio (ORs) with 95% confidence interval (CI) were calculated initially with a bivariate and then multivariate analysis.

Results

We included 179 cases matched to 1770 controls. Adjusted OR for acute serious liver injury associated with all NSAIDs was 1.69, 95% CI 1.21–2.37. Thirty cases were exposed to nimesulide (adjusted OR 2.10, 95% CI 1.28–3.47); the risk increased according to the length of exposure (OR > 30 days: 12.55, 95% CI 1.73–90.88) and to higher doses (OR 10.69, 95% CI 4.02–28.44). Risk of hepatotoxicity was increased also for ibuprofen, used both at recommended dosages (OR 1.92, 95% CI 1.13–3.26) and at higher doses (OR 3.73, 95% CI 1.11–12.46) and for ketoprofen ≥ 150 mg (OR 4.65, 95% CI 1.33–10.00).

Conclusion

Among all NSAIDs, nimesulide is associated with the higher risk, ibuprofen and high doses of ketoprofen are also associated with a modestly increased risk of hepatotoxicity.

Herb-Induced Liver Injury in the Berlin Case-Control Surveillance Study

Herb-induced liver injury (HILI) has recently attracted attention due to increasing reports of hepatotoxicity associated with use of phytotherapeutics. Here, we present data on HILI from the Berlin Case-Control Surveillance Study. The study was initiated in 2000 to investigate the serious toxicity of drugs including herbal medicines. Potential cases of liver injury were ascertained in more than 180 Departments of all 51 Berlin hospitals from October 2002 to December 2011. Drug or herb intake was assessed through a standardized face-to-face interview. Drug or herbal aetiology was assessed based on the updated Council for International Organizations of Medical Sciences scale. In ten of all 198 cases of hepatotoxicity included in the study, herbal aetiology was assessed as probable (once ayurvedic herb) or possible (Valeriana five times, Mentha piperita once, Pelargonium sidoides once, Hypericum perforatum once, Eucalyptus globulus once). Mean age was 56.4 ± 9.7 years, and the predominant pattern of liver injury was hepatocellular. No cases of acute liver failure or death were observed. This case series corroborates known risks for ayurvedic herbs, supports the suspected association between Valeriana use and liver injury, and indicates a hepatotoxic potential for herbs such as Pelargonium sidoides, Hypericum perforatum or Mentha piperita that were rarely associated with liver injury before. However, given that possible causality does not prove clinical significance, further studies in this field are needed.