Risk of acute liver injury associated with the use of drugs: a multicentre population survey

Mapping the incidence of drug-induced liver injury: A systematic review and meta-analysis

OBJECTIVES

Drug-induced liver injury (DILI) is an increasing etiology of liver dysfunction, with various incidence worldwide. To better understand the disease burden and establish appropriate preventive and treatment strategies, a systematic review and meta-analysis was conducted.

METHODS

PubMed, EMBASE, Web of Science, and Cochrane Library were searched for studies on the incidence of DILI published up to June 1, 2022. According to the predefined criteria, only population-based studies were included. Incidence was presented as cases per 100 000 person-years with 95% confidence interval (CI) using a random-effects model.

RESULTS

A total of 14 studies were included. The overall incidence of DILI was 4.94 per 100 000 person-years (95% CI 4.05-5.83). Time-based cumulative meta-analysis suggested that the incidence of DILI increased over time since 2010. The incidence varied by regions, with Asia having the highest incidence of 17.82 per 100 000 person-years (95% CI 6.26-29.38), while North America having the lowest incidence of 1.72 per 100 000 person-years (95% CI 0.48-2.95). All studies reported a higher incidence of DILI in the elderly but comparable incidences between male and female (3.42 per 100 000 person-years vs 4.64 per 100 000 person-years).

CONCLUSIONS

The global incidence of DILI has been increasing since 2010, with the highest incidence in Asia. Understanding the epidemiological characteristics of DILI helps establish specific strategies to deal with this emerging health problems.

Common Gastrointestinal Medications Implicated in Drug-Induced Liver Injury

Content available: Author Interview and Audio Recording.

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The analgesic metamizole, which has been withdrawn from the market in several countries due to the risk of agranulocytosis but is still available on the market in Germany and some other countries, has been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.

Co-abuse of alprazolam augments the hepato-renal toxic effects of methylphenidate

OBJECTIVE:

Methylphenidate (MPH) is a first-line treatment option for attention-deficit hyperactive disorder and narcolepsy. MPH is one of the most abused psychostimulants by the adults and young population to stay awake, perform better, or improve concentration. The scanty reports say that the medical users or abusers mostly consider the administration of benzodiazepines to overcome the adverse effects, i.e., mood- and anxiety-related problems associated with MPH chronic abuse. This work aims to study the effect of alprazolam (ALZ) on MPH-associated adverse effects on liver and kidney.

MATERIALS AND METHODS:

Female Wistar rats (n = 58) were administered with MPH (10, 20, and 40 mg/kg) and ALZ (5, 10, and 20 mg/kg) alone and in combination for 28 days. Bodyweight, feed intake, and water intake were monitored weekly. Parameters related to liver and renal function, oxidative stress, and histopathology were performed to evaluate the toxic impacts on the liver and kidneys.

RESULTS:

ALZ, along with MPH, increased the serum alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, creatinine, and urea levels. The co-abuse also led to elevated oxidative stress and structural abnormalities in the liver and kidney tissues.

CONCLUSION:

The co-abuse of ALZ has amplified the hepato-renal toxic effects of MPH. Therefore, it is a significant concern for public safety, and their co-abuse must be restricted and discouraged.

Dual versus single vessel normothermic ex vivo perfusion of rat liver grafts using metamizole for vasodilatation

Background

Normothermic ex vivo liver perfusion (NEVLP) is a promising strategy to increase the donor pool in liver transplantation. Small animal models are essential to further investigate questions regarding organ preservation and reconditioning by NEVLP. A dual vessel small animal NEVLP (dNEVLP) model was developed using metamizole as a vasodilator and compared to conventional portovenous single vessel NEVLP (sNEVLP).

Methods

Livers of male Wistar rats were perfused with erythrocyte-supplemented culture medium for six hours by either dNEVLP via hepatic artery and portal vein or portovenous sNEVLP. dNEVLP was performed either with or without metamizole treatment. Perfusion pressure and flow rates were constantly monitored. Transaminase levels were determined in the perfusate at the start and after three and six hours of perfusion. Bile secretion was monitored and bile LDH and GGT levels were measured hourly. Histopathological analysis was performed using liver and bile duct tissue samples after perfusion.

Results

Hepatic artery pressure was significantly lower in dNEVLP with metamizole administration. Compared to sNEVLP, dNEVLP with metamizole treatment showed higher bile production, lower levels of transaminases during and after perfusion as well as significantly lower necrosis in liver and bile duct tissue. Biochemical markers of bile duct injury showed the same trend.

Conclusion

Our miniaturized dNEVLP system enables normothermic dual vessel rat liver perfusion. The administration of metamizole effectively ameliorates arterial vasospasm allowing for six hours of dNEVLP, with superior outcome compared to sNEVLP.

Drug induced liver injury: East versus West - a systematic review and meta-analysis

Drug induced liver injury (DILI) may be different in the East compared to the West due to differing disease prevalence, prescribing patterns and pharmacogenetic profiles. To review existing literature on causative agents of DILI in the East compared to the West, a comprehensive literature search was performed on electronic databases: MEDLINE/PubMed, Embase, Cochrane Library and China National Knowledge Infrastructure without language restrictions. Studies which involve patients having DILI and reported the frequency of causative agents were included. A random effects model was applied to synthesize the current evidence using prevalence of class-specific and agent-specific causative drugs with 95% confidence intervals. Of 6,914 articles found, 12 showed the distribution of drugs implicated in DILI in the East with a total of 33,294 patients and 16 in the West with a total of 26,069 DILI cases. In the East, the most common agents by class were anti-tuberculosis drugs (26.6%), herbal and alternative medications (25.3%), and antibiotics (15.7%), while in the West, antibiotics (34.9%), cardiovascular agents (17.3%), and non-steroidal anti-inflammatory drugs (12.5%) were the commonest. For individual agents, the most common agents in the East were isoniazid-rifampicin-pyrazinamide (25.4%), phenytoin (3.5%), and cephalosporin (2.9%) while in the West, amoxicillin-potassium clavulanate combination acid (11.3%), nimesulide (6.3%), and ibuprofen (6.1%) were the commonest. There was significant heterogeneity due to variability in single-centre compared to multi-centre studies. Differences in DILI in the East versus the West both in drug classes and individual agents are important for clinicians to recognize.

The Protective Effect of Nitroglycerin, N-Acetyl Cysteine and Metoprolol in CCL4 Induced Animal Model of Acute Liver Injury

OBJECTIVE:

The current study was designed to determine the hepatoprotective effect of well-known drugs. Nitroglycerin, N-acetyl cysteine and Metoprolol in acute liver injury induced by CCL4. The antioxidant effects of b-blockers, especially carvedilol, have been described by several investigators. However, for metoprolol, the effect is a bit query as there is only one in-vitro study showing a little hepatoprotective effect. Thus, it is worthy to re-study the hepatoprotective effect of metoprolol.

AIM:

To explore the possible hepatoprotective effect of Nitroglycerin, N-acetyl cysteine and Metoprolol Tartrate

MATERIAL AND METHODS:

The normal serum values of ALP, AST, ALT, TSB and TSP were determined in 35 healthy rabbits allocated to 5 groups before CCL4 induction and at three occasions 24, 72, 120 hrs after induction by CCL4 and treatment with the tested drugs: Nitroglycerin, N-acetyl cysteine and Metoprolol for five successive days.

RESULTS:

Showed significant decrease in serum levels of ALP, AST, ALT and TSB with a significant increase in TSP level of all the tested drugs measured at 120 hrs compared with the control and their levels measured at 24, 72 hrs.

CONCLUSION:

All the tested drugs proved in having a hepatoprotective effect when they are given orally to animals. The histopathological sections of the liver tissue supported the real effect of these drugs in the management of ALI.

A prospective study of the incidence of drug-induced liver injury by the modern volatile anaesthetics sevoflurane and desflurane

BACKGROUND

Volatile anaesthetics are known to cause drug-induced liver injury, a hepatotoxic reaction characterised by antibodies to trifluoroacetylated lipid and protein adducts and cytochrome p450 2E1. The incidence of volatile anaesthetic drug-induced liver injury from older agents has been described, but modern agents have not been prospectively studied.

AIM

To determine prospectively the incidence of volatile anaesthetic drug-induced liver injury from sevoflurane and desflurane.

METHODS

Adult surgical patients with a predicted post-operative stay of at least 4 days were recruited. If volatile anaesthetic was administered, liver biochemistry was performed regularly. Medications, observations and other investigations were documented. Patients with abnormal liver biochemistry were classified as likely volatile anaesthetic drug-induced liver injury or not based on clinical assessment, Roussel Uclaf Causality Assessment Method score, and the absence of other likely pathology. Some patients were also tested for antibodies to both trifluoroacetylated lipid and protein adducts, and cytochrome p450 2E1.

RESULTS

A total of 209 patients were recruited, of which 121 were included for analysis. Post-operative liver biochemistry was abnormal in 62 patients (51.2%); further classified as not volatile anaesthetic drug-induced liver injury in 47 cases (38.8%), and likely volatile anaesthetic-drug induced liver injury in 15 cases (12.4%). Of the likely volatile anaesthetic drug-induced liver injury patients, only one had severe disease with alanine transaminase greater than five times the upper limit of normal, while four cases had moderate disease with alanine transaminase greater than three times the upper limit of normal. Thus, the incidence of clinically significant volatile anaesthetic drug-induced liver injury was 4.1%. No risk factors were identified.

CONCLUSIONS

Volatile anaesthetic drug-induced liver injury from modern agents seems to be as common (4.1%) as previously reported with older agents (3%), and may identify patients at risk of severe acute liver injury with subsequent re-exposure.

Nimesulide-induced hepatotoxicity: A systematic review and meta-analysis

Objective

This study aimed to evaluate the risk for hepatotoxicity with nimesulide, a non-steroidal anti-inflammatory drug (NSAID) available in Republic of Korea but withdrawn from the market in several countries.

Methods

A systematic review and meta-analysis were conducted of studies retrieved from PubMed, EMBASE, Cochrane, the Research Information Sharing Service and ClinicalTrials.gov up to September 2017. All studies reporting nimesulide-associated hepatotoxicity in patients as compared with the unexposed or the exposed to other NSAIDs were included. Studies using spontaneous reporting databases were included to estimate reporting odds ratio (ROR) of hepatotoxicity associated with nimesulide exposure. The association between nimesulide use and hepatotoxicity was estimated using relative risk (RR) and ROR with 95% confidence interval (CI).

Results

A total of 25 observational studies were eligible for review. In a meta-analysis of five observational studies, nimesulide was significantly associated with hepatotoxicity [RR 2.21, 95% CI 1.72–2.83]. From studies using spontaneous reporting databases (n = 6), rates of reported hepatotoxicity were significantly higher in patients using nimesulide, compared with those treated with other NSAIDs [pooled ROR 3.99, 95% CI 2.86–5.57]. Of a total of 33 patients from case studies and series, the majority (n = 28, 84.8%) were female, and the mean age (± standard deviation) was 56.8 (± 15.6) years. Almost half of the patients on nimesulide (45.5%) either required liver transplantation or died due to fulminant hepatic failure, of whom a third developed hepatotoxicity within less than 15 days of nimesulide administration.

Conclusions

Our study findings support previous reports of an increased risk for hepatotoxicity with nimesulide use and add to existing literature by providing risk estimates for nimesulide-associated hepatotoxicity. As the limited number of studies with primarily observational study designs were included in the analysis, more studies are needed to further describe the effects of dose and length of treatment on the risk for hepatotoxicity.

Risk of hospital admission for liver injury in users of NSAIDs and nonoverdose paracetamol: Preliminary results from the EPIHAM study

PURPOSE

The SALT study found similar per-user risks of acute liver failure (ALF) leading to transplantation (ALFT) between NSAIDs and a threefold higher risk in nonoverdose paracetamol (NOP) users. The objective of EPIHAM was to identify the risks of hospital admission for acute liver injury (ALI) associated with NSAIDs and NOP.

METHODS

Case-population study in the 1/97 sample of the French population claims database. Acute liver injury was identified from hospital discharge summaries, from 2009 to 2013. Exposure for cases was dispensing of NSAID or NOP resulting in exposure within 30 days before admission. Population exposure was the number of patients using the drugs over the study timeframe and total number of DDD dispensed.

RESULTS

Of 63 cases of ALI, 13 had been exposed to NSAIDs and 24 to NOP. Events per million DDD (95% CI) ranged from 0.46 (0.09-1.34) (ketoprofen) to 1.43 (0.04-7.97) (diclofenac combinations), 0.43 (0.23-0.73) all NSAIDs combined, 0.58 (0.37-0.86) for NOP. There was no association with average duration of treatment. Per patient risk ranged from 19.5 (5.31-49.9) (ibuprofen) per million users to 37.2 (19.8-63.6) all NSAIDs combined, 58.0 (37.2-86.3) for NOP. There was a linear relationship between average treatment duration and per-user risk (R²  = 0.51, P < .05 for NSAIDs, R²  = 0.97, P < .01 for NOP).

CONCLUSIONS

Risk of hospital admission for ALI with NSAIDs and NOP was similar and indicative of a dose and duration-related effect (pharmacological) effect. Acute liver injury rates were not predictive of ALFT risk.

Association between proton pump inhibitors and the risk of hepatocellular carcinoma

BACKGROUND

Proton pump inhibitor (PPI) use has been reported to be associated with liver damage and might possibly be carcinogenic.

AIMS

We examined whether long-term PPI use increases the risk of hepatocellular carcinoma (HCC) in patients without viral hepatitis B or C.

METHODS

We conducted a nested case-control study in a cohort of patients without viral hepatitis in Taiwan from 2000 to 2013. In total, 29 473 HCC cases and 294 508 matched controls were included. Moreover, we identified prescriptions for PPI and durations between the PPI index date and cancer diagnosis date (or the corresponding date in controls).

RESULTS

The adjusted odds ratio (AOR) for HCC associated with PPI use was 2.86 (95% confidence interval [CI], 2.69-3.04). Considering the use of PPIs determined according to cumulative defined daily dose (cDDD) subgroups, a dose-response effect was observed in patients exposed to 29-180, 181-240, 241-300, and 300+ cDDDs of PPIs. The AORs were 2.74 (95% CI, 2.57-2.93), 2.98 (95% CI, 2.50-3.56), 3.23 (95% CI, 2.59-4.02), and 3.43 (95% CI, 2.94-4.00) in the 29-180, 181-240, 241-300, and 300+ cDDD groups, respectively, compared with the 0-28 cDDD group. A sensitivity analysis revealed a consistent association between PPI use and the risk of HCC in subpopulations stratified by risk factors associated with HCC.

CONCLUSIONS

This observational study demonstrated that PPIs might increase the risk of HCC.

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.

Severe Drug-Induced Liver Injury as an Adverse Drug Event of Antibiotics: A Case Report and Review of the Literature

Drug-induced liver injury is one of the main reasons for acute liver failure. We report the case of a young patient who experienced a drug-induced liver injury resulting in life-threatening acute liver failure after treatment with different antibiotics (amoxicillin, ciprofloxacin, cefazolin, clindamycin) and acetaminophen, or a combination of these drugs. Moreover, we provide an overview of the hepatotoxic potential of these drugs.

Liver Illness and Psychiatric Patients

Patients with psychiatric disorders are usually more exposed to multiple somatic illnesses, including liver diseases. Specific links are established between psychiatric disorders and alcohol hepatitis, hepatitis B, and hepatitis C in the population as a whole, and specifically in drug abusers. Metabolic syndrome criteria, and associated steatosis or non-alcoholic steato-hepatitis (NASH) are frequent in patients with chronic psychiatric disorders under psychotropic drugs, and should be screened. Some psychiatric medications, such as neuroleptics, mood stabilizers, and a few antidepressants, are often associated with drug-induced liver injury (DILI). In patients with advanced chronic liver diseases, the prescription of some specific psychiatric treatments should be avoided. Psychiatric disorders can be a limiting factor in the decision-making and following up for liver transplantation.

Safety of metamizole: a systematic review of the literature

WHAT IS KNOWN AND OBJECTIVE

Metamizole was withdrawn from the market in the United States and several European countries following reports of fatal agranulocytosis among users, but is still available in many countries in Europe, South America and Asia. Over the past several decades, a number of epidemiologic studies have been conducted to quantify the risk of agranulocytosis and other adverse effects associated with metamizole and other non-narcotic analgesics. The objective of this study was to perform a systematic review of the safety of metamizole.

METHODS

Epidemiologic studies published between 1 January 1980 and 15 December 2014 were identified through systematic searches of PubMed and Google Scholar; the reference sections of selected articles were also reviewed to identify potentially relevant studies. Studies included in this review focused on the safety of metamizole, that is on outcomes such as haematologic abnormalities, gastrointestinal bleeding, anaphylaxis and hepatotoxicity. Two study investigators independently reviewed the abstracts and articles to determine relevant studies according to prespecified criteria.

RESULTS AND DISCUSSION

A total of 22 articles met the criteria for evaluation. The majority of studies that evaluated agranulocytosis indicated an increased risk associated with metamizole, with relative risk (RR) estimates ranging from 1·5 (95% CI, 0·8-2·7) to 40·2 (95% CI, 14·7-113·3). Findings of three case-control studies do not suggest an association between metamizole and aplastic anaemia. Of the five case-control studies that evaluated the risk of upper gastrointestinal bleeding, four found a statistically significant increased risk associated with metamizole (RR estimates ranging from 1·4 to 2·7). There is insufficient evidence to determine whether metamizole increases the risk of other outcomes (e.g. hepatic effects, anaphylaxis, congenital anomalies). Few studies evaluated the effects of dose, route of administration or duration of therapy.

WHAT IS NEW AND CONCLUSION

Published studies reported differences in the magnitude of risk of adverse outcomes associated with metamizole use and often had small sample sizes and a number of other limitations that may have biased the results. Further research is needed to better quantify the potential risks associated with metamizole compared to other non-narcotic analgesics.

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.

Systematic Review and Meta-Analysis: Macrolides- and Amoxicillin/Clavulanate-induced Acute Liver Injury

Antibacterials are frequently associated with idiosyncratic drug-induced liver injury (DILI). The objective of this study was to estimate the risk of macrolides and amoxicillin/clavulanate (AMC) on DILI. We conducted a systematic review (SR) and meta-analysis (MA) with studies retrieved from PubMed, Cochrane Library Plus, Web of Knowledge, clinicaltrials.gov, Livertox and Toxline (1980-2014). We searched for macrolides, AMC and MeSH and synonym terms for DILI. We included all study designs except case reports/series, all population ages and studies with a placebo/non-user comparator. We summarized the evidence with a random-effects MA. Quality of the studies was appraised with a checklist developed for SR of adverse effects. Heterogeneity and publication bias were assessed with different exploratory tools. We finally included 10 (two randomized clinical trials, six case-control, one cohort and one case-population studies) and 9 (case-population excluded) articles in the SR and MA, respectively. The overall summary relative risk of DILI for macrolides was 2.85 [95% confidence interval (CI) 1.81-4.47], p < 0.0001, I(2) = 57%. Three studies were perceived to be missing in the area of low statistical significance. Year of study and selected exposure window partly explained the variability between studies. For AMC, the risk of DILI was 9.38 (95% CI 0.65-135.41) p = 0.3, I2 = 95%. In conclusion, although spontaneous reports and case series have long established an association between macrolides and AMC with acute liver injury, these SR and MA have assessed the magnitude of this association. The low incidence of DILI and the therapeutic place of these antibiotics might tilt the balance in favour of their benefits.

Chronic liver injury induced by drugs: a systematic review

To examine the available literature and summarize what is known about chronic drug-induced liver injury. We reviewed PubMed/MEDLINE through March 2015. We developed a MEDLINE search strategy using PubMed medical subject heading terms chronic liver injury, hepatotoxicity, drug-induced liver injury, cirrhosis and chronic liver disease. We reviewed the reference list of included articles to identify articles missed in the database search. Chronic liver injury from drugs is more common than once thought with prevalence as high as 18% based on large national registries. Patients with cholestatic injury, age ≤65 years, and a long latency period (>365 days) are at increased risk. Of the most common drugs associated with drug-induced liver injury, antibiotics (amoxicillin-clavulanic acid, trimethoprim-sulfamethoxazole, azithromycin) are most likely to cause chronic injury. The presence of autoantibodies is common with chronic DILI, however, it is not diagnostic nor is it specific to autoimmune-like drug-induced liver injury. Immunosuppressive therapy may be necessary for individual cases of autoimmune-like drug-induced liver injury where cessation of the drug alone does not result in resolution of injury, however, the lowest dose should be used for the shortest duration with careful attention to the development of side effects. The effectiveness of treament of cholestatic liver injury with corticosteroids or ursodiol remains unclear. Cases of drug-induced fatty liver, nodular regenerative hyperplasia and peliosis hepatitis are less common subtypes of chronic drug-induced liver injury that deserve special consideration. A high degree of clinical suspicion is required for the diagnosis of chronic drug-induced liver injury and should be suspected in any patient with liver associated enzyme abnormalities that persist out past 6 months of initial presentation. Treatment with drug removal and/or immunosuppressive therapy appears to be effective for the majority of cases. More study into pharmacogenomics and personalized medicine may aid in predicting which patients will go on to develop chronic drug-induced liver injury.

Development of HepG2-derived cells expressing cytochrome P450s for assessing metabolism-associated drug-induced liver toxicity

The generation of reactive metabolites from therapeutic agents is one of the major mechanisms of drug-induced liver injury (DILI). In order to evaluate metabolism-related toxicity and improve drug efficacy and safety, we generated a battery of HepG2-derived cell lines that express 14 cytochrome P450s (CYPs) (1A1, 1A2, 1B1, 2A6, 2B6, 2C8, 2C9, 2C18, 2C19, 2D6, 2E1, 3A4, 3A5 and 3A7) individually using a lentiviral expression system. The expression/production of a specific CYP in each cell line was confirmed by an increased abundance of the CYP at both mRNA and protein levels. Moreover, the enzymatic activities of representative CYPs in the corresponding cell lines were also measured. Using our CYP-expressed HepG2 cells, the toxicity of three drugs that could induce DILI (amiodarone, chlorpromazine and primaquine) was assessed, and all of them showed altered (increased or decreased) toxicity compared to the toxicity in drug-treated wild-type HepG2 cells. CYP-mediated drug toxicity examined in our cell system is consistent with previous reports, demonstrating the potential of these cells for assessing metabolism-related drug toxicity. This cell system provides a practical in vitro approach for drug metabolism screening and for early detection of drug toxicity. It is also a surrogate enzyme source for the enzymatic characterization of a particular CYP that contributes to drug-induced liver toxicity.

Bridging differences in outcomes of pharmacoepidemiological studies: design and first results of the PROTECT project

Background:

Observational pharmacoepidemiological (PE) studies on drug safety have produced discrepant results that may be due to differences in design, conduct and analysis.

Purpose:

The pharmacoepidemiology work-package (WP2) of the Pharmacoepidemiological Research on Outcomes of Therapeutics by a European ConsorTium (PROTECT) project aims at developing, testing and disseminating methodological standards for design, conduct and analysis of pharmacoepidemiological studies applicable to different safety issues using different databases across European countries. This article describes the selection of the safety issues and the description of the databases to be systematically studied.

Methods:

Based on two consensus meetings and a literature search, we selected five drug-adverse event (AE) pairs to be evaluated in different databases. This selection was done according to pre-defined criteria such as regulatory and public health impact, and the potential to investigate a broad range of methodological issues.

Results:

The selected drug-AE pairs are: 1) inhaled long-acting beta-2 agonists and acute myocardial infarction; 2) antimicrobials and acute liver injury; 3) antidepressants and/or benzodiazepines and hip fracture; 4) anticonvulsants and suicide/suicide attempts; and 5) calcium channel blockers and malignancies. Six European databases, that will be used to evaluate the drug-AE pairs retrospectively, are also described.

Conclusion:

The selected drug-AE pairs will be evaluated in PE studies using common protocols. Based on consistencies and discrepancies of these studies, a framework for guiding methodological choices will be developed. This will increase the usefulness and reliability of PE studies for benefit-risk assessment and decision-making.

Signal detection of potentially drug-induced acute liver injury in children using a multi-country healthcare database network

BACKGROUND

Data mining in spontaneous reporting databases has shown that drug-induced liver injury is infrequently reported in children.

OBJECTIVES

Our objectives were to (i) identify drugs potentially associated with acute liver injury (ALI) in children and adolescents using electronic healthcare record (EHR) data; and (ii) to evaluate the significance and novelty of these associations.

METHODS

We identified potential cases of ALI during exposure to any prescribed/dispensed drug for individuals <18 years old from the EU-ADR network, which includes seven databases from three countries, covering the years 1996-2010. Several new methods for signal detection were applied to identify all statistically significant associations between drugs and ALI. A drug was considered statistically significantly associated with ALI, using all other time as a reference category, if the 95% CI lower band of the relative risk was >1 and in the presence of at least three exposed cases of ALI. Potentially new signals were distinguished from already known associations concerning ALI (whether in adults and/or in the paediatric population) through manual review of published literature and drug product labels.

RESULTS

The study population comprised 4,838,146 individuals aged <18 years, who contributed an overall 25,575,132 person-years of follow-up. Within this population, we identified 1,015 potential cases of ALI. Overall, 20 positive drug-ALI associations were detected. The associations between ALI and domperidone, flunisolide and human insulin were considered as potentially new signals. Citalopram and cetirizine have been previously described as hepatotoxic in adults but not in children, while all remaining associations were already known in both adults and children.

CONCLUSIONS

Data mining of multiple EHR databases for signal detection confirmed known associations between ALI and several drugs, and identified some potentially new signals in children that require further investigation through formal epidemiologic studies. This study shows that EHRs may complement traditional spontaneous reporting systems for signal detection and strengthening.

Defining a reference set to support methodological research in drug safety

BACKGROUND

Methodological research to evaluate the performance of methods requires a benchmark to serve as a referent comparison. In drug safety, the performance of analyses of spontaneous adverse event reporting databases and observational healthcare data, such as administrative claims and electronic health records, has been limited by the lack of such standards.

OBJECTIVES

To establish a reference set of test cases that contain both positive and negative controls, which can serve the basis for methodological research in evaluating methods performance in identifying drug safety issues.

RESEARCH DESIGN

Systematic literature review and natural language processing of structured product labeling was performed to identify evidence to support the classification of drugs as either positive controls or negative controls for four outcomes: acute liver injury, acute kidney injury, acute myocardial infarction, and upper gastrointestinal bleeding.

RESULTS

Three-hundred and ninety-nine test cases comprised of 165 positive controls and 234 negative controls were identified across the four outcomes. The majority of positive controls for acute kidney injury and upper gastrointestinal bleeding were supported by randomized clinical trial evidence, while the majority of positive controls for acute liver injury and acute myocardial infarction were only supported based on published case reports. Literature estimates for the positive controls shows substantial variability that limits the ability to establish a reference set with known effect sizes.

CONCLUSIONS

A reference set of test cases can be established to facilitate methodological research in drug safety. Creating a sufficient sample of drug-outcome pairs with binary classification of having no effect (negative controls) or having an increased effect (positive controls) is possible and can enable estimation of predictive accuracy through discrimination. Since the magnitude of the positive effects cannot be reliably obtained and the quality of evidence may vary across outcomes, assumptions are required to use the test cases in real data for purposes of measuring bias, mean squared error, or coverage probability.

Successful treatment of hepatic failure secondary to diazepam administration in a cat

A 2-year-old castrated male domestic shorthair cat developed acute hepatic failure following oral diazepam administration for behavioral problems. The patient survived with intensive supportive care and was discharged after 5 days in hospital. Successful treatment of diazepam-associated fulminant hepatic failure in cats has rarely been described in the veterinary literature.

Paracetamol in therapeutic dosages and acute liver injury: causality assessment in a prospective case series

Background

Acute liver injury (ALI) induced by paracetamol overdose is a well known cause of emergency hospital admission and death. However, there is debate regarding the risk of ALI after therapeutic dosages of the drug.

The aim is to describe the characteristics of patients admitted to hospital with jaundice who had previous exposure to therapeutic doses of paracetamol. An assessment of the causality role of paracetamol was performed in each case.

Methods

Based on the evaluation of prospectively gathered cases of ALI with detailed clinical information, thirty-two cases of ALI in non-alcoholic patients exposed to therapeutic doses of paracetamol were identified. Two authors assessed all drug exposures by using the CIOMS/RUCAM scale. Each case was classified into one of five categories based on the causality score for paracetamol.

Results

In four cases the role of paracetamol was judged to be unrelated, in two unlikely, and these were excluded from evaluation. In seven of the remaining 26 cases, the RUCAM score associated with paracetamol was higher than that associated with other concomitant medications. The estimated incidence of ALI related to the use of paracetamol in therapeutic dosages was 0.4 per million inhabitants older than 15 years of age and per year (99%CI, 0.2-0.8) and of 10 per million paracetamol users-year (95% CI 4.3-19.4).

Conclusions

Our results indicate that paracetamol in therapeutic dosages may be considered in the causality assessment in non-alcoholic patients with liver injury, even if the estimated incidence of ALI related to paracetamol appears to be low.

Hepatic safety of antibiotics used in primary care

Antibiotics used by general practitioners frequently appear in adverse-event reports of drug-induced hepatotoxicity. Most cases are idiosyncratic (the adverse reaction cannot be predicted from the drug's pharmacological profile or from pre-clinical toxicology tests) and occur via an immunological reaction or in response to the presence of hepatotoxic metabolites. With the exception of trovafloxacin and telithromycin (now severely restricted), hepatotoxicity crude incidence remains globally low but variable. Thus, amoxicillin/clavulanate and co-trimoxazole, as well as flucloxacillin, cause hepatotoxic reactions at rates that make them visible in general practice (cases are often isolated, may have a delayed onset, sometimes appear only after cessation of therapy and can produce an array of hepatic lesions that mirror hepatobiliary disease, making causality often difficult to establish). Conversely, hepatotoxic reactions related to macrolides, tetracyclines and fluoroquinolones (in that order, from high to low) are much rarer, and are identifiable only through large-scale studies or worldwide pharmacovigilance reporting. For antibiotics specifically used for tuberculosis, adverse effects range from asymptomatic increases in liver enzymes to acute hepatitis and fulminant hepatic failure. Yet, it is difficult to single out individual drugs, as treatment always entails associations. Patients at risk are mainly those with previous experience of hepatotoxic reaction to antibiotics, the aged or those with impaired hepatic function in the absence of close monitoring, making it important to carefully balance potential risks with expected benefits in primary care. Pharmacogenetic testing using the new genome-wide association studies approach holds promise for better understanding the mechanism(s) underlying hepatotoxicity.

Nimesulide-induced electrophile stress activates Nrf2 in human hepatocytes and mice but is not sufficient to induce hepatotoxicity in Nrf2-deficient mice

Nimesulide is a widely prescribed nitroaromatic sulfoanilide-type nonsteroidal anti-inflammatory drug that, despite its favorable safety profile, has been associated with rare cases of idiosyncratic drug-induced liver injury (DILI). Because reactive metabolites have been implicated in DILI, we aimed at investigating whether hepatic bioactivation of nimesulide produces a protein-reactive intermediate in hepatocytes. Also, we explored whether nimesulide can activate the transcription factor Nrf2 that would protect from drug-induced hepatocyte injury. We found that [(14)C]-nimesulide covalently bound to human liver microsomes (<50 pmol/mg under standard conditions) or immortalized human hepatocytes in a sulfaphenazole-sensitive, rifampicin-inducible manner; yet the overall extent of binding was modest. Although exposure of hepatocytes to nimesulide was not associated with increased net levels of superoxide anion, nimesulide (100 microM, 24 h) caused nuclear translocation of Nrf2 in a sulfaphenazole-sensitive manner, indicating a role of electrophilic metabolites. However, knockdown of Nrf2 with siRNA did not make the cells more sensitive to nimesulide-induced cell injury. Similarly, exposure of wild-type C57BL/6x129 Sv mice to nimesulide (100 mg/kg/day, po, for 5 days) was associated with nuclear translocation of immunoreactive Nrf2 in a small number of hepatocytes and induced >2-fold the expression levels of the Nrf2-target gene Nqo1 in wild-type but not Nrf2-null mice. Nimesulide administered to Nrf2(-/-) knockout mice did not cause increases in serum ALT activity or any apparent histopathological signs of liver injury. In conclusion, these data indicate that nimesulide is bioactivated by CYP2C to a protein-reactive electrophilic intermediate that activates the Nrf2 pathway even at nontoxic exposure levels.

The predictors of complications in patients with drug-induced liver injury caused by antimicrobial agents

BACKGROUND

Antimicrobials are the leading cause of idiosyncratic drug-induced liver injury in most series.

AIM

To determine the incidence and the predictors of complications in patients with drug-induced liver injury caused by antimicrobial agents requiring hospitalization.

METHODS

Medical records of patients with drug-induced liver injury caused by antimicrobial agents were identified by ICD-10, for the period between 2002 and 2006. Clinical information and blood tests during hospitalization were recorded. The causality assessment of drug-induced liver injury was determined by the Roussel UCLAF causality assessment method (RUCAM) scale.

RESULTS

Of 47 594 in-patient admissions per year, the annual incidence of drug-induced liver injury was 0.03%. Male: female ratio was 7:3 with a median age of 47 years. Eighty reactions of drug-induced liver injury were caused by anti-tuberculosis drugs (85%) and by antibiotics (15%). The median (IQR) of RUCAM scale was 6 (5-8). A total of 36% had HIV infection and 9% of patients had diabetes mellitus. Median (IQR) duration of hospitalization was 9 (5-15) days. Serious complications and death were found in 27.5% and 26%, respectively. By a multivariable logistic analysis, the presence of jaundice was found to be significantly associated with an unfavourable outcome.

CONCLUSION

Although rare, antimicrobial agents-related drug-induced liver injury requiring hospitalization has a high mortality rate. The presence of jaundice predicts poor outcome.

Antibiotic prescribing over the last 16 years: fewer antibiotics but the spectrum is broadening

The purpose of this study was to quantify the antibiotics prescribed in the outpatient setting of all primary health care professionals in Catalonia during 1992-2007. We calculated prescribed defined daily doses per 1,000 inhabitants and day (DID) from data provided by the Catalonian Health Service. The antibiotics analysed belonged to the J01 group (ATC/DDD classification). The overall prescribing of antibacterials has decreased by 11.9% during this period (1992: 16.75 DID, 2007: 14.75 DID). During this 16-year period, an increase was observed for penicillins (from 46.1% in 1992 to 59.6% in 2007) and for quinolones (from 13.3% to 15.7%). The prescription of cephalosporins remained steady and, conversely, a decrease in macrolides was found (from 14.8% to 12.2%). The leading antibiotic prescribed in 2007 was amoxicillin plus clavulanic acid (5.15 DID), followed by amoxicillin (2.95 DID). The former has increased by 84.4% since 2002. Penicillin V prescribing reached a peak in 2007 with 0.034 DID. There has been a slight reduction in antibiotic prescription in this 16-year study, with an increase of penicillins, mainly at the expense of those of broader antibacterial spectrum. Awareness of the rational use of antibiotics is mandatory, basically aimed at reducing the overall prescribing of antibiotics and encouraging those with a narrower spectrum.

Nimesulide associated fulminant hepatic failure

PURPOSE

It is controversial whether the non-steroidal inflammatory drug nimesulide is associated with severe hepatotoxicity. Our objective was to determine whether nimesulide is associated with fulminant hepatic failure.

METHODS

Retrospective cohort study in the Irish national liver transplant unit. All patients who received a liver transplant for fulminant hepatic failure of unknown cause, between January 1994 and March 2007, were evaluated. New medications started within 6 months prior to transplant were identified. Likelihood of association assessed using the Naranjo and Roussel UCLAF Causality Assessment Method (RUCAM) scoring systems.

RESULTS

Thirty-two patients with sero-negative, non-paracetamol fulminant hepatic failure, who received an emergency liver transplant, were identified. Nimesulide had been started within 6 months in 6 patients. Five of the six were middle aged females. Nimesulide was assessed as probably associated with liver injury in all six cases.

CONCLUSIONS

Nimesulide was associated with fulminant hepatic failure requiring liver transplant in 6/32 cases of unknown origin. This association requires further investigation.

Serious drug-induced liver disease secondary to ezetimibe

Ezetimibe is the first member of a new family of lipid-lowering drugs that inhibits uptake of dietary and biliary cholesterol. It was approved by the FDA in 2002 for hypercholesterolemia alone or in combination with statins. Its use has been spreading over the last years. Ezetimibe was considered a safe drug. We report a case of a woman who developed a serious hepatocellular drug-induced liver disease after 4 mo therapy with 10 mg daily of ezetimibe. After withdrawal of the drug, the patient recovered slowly. Ezetimibe may produce serious toxic hepatitis and prompt withdrawal is mandatory in case of a significant abnormality in liver testing after beginning or during treatment with ezetimibe.