Drug-induced liver injury (DILI) remains an active field of clinical research and investigation with more than 4700 publications appearing in 2023 relating to hepatotoxicity of all causes and injury patterns. As in years past, we have attempted to identify and summarize highlights and controversies from the past year's literature. Several new and novel therapeutic agents were approved by the US Food and Drug Administration (FDA) in 2023, a number of which were associated with significant hepatotoxicity. Updates in the diagnosis and management of DILI using causality scores as well as newer artificial intelligence-based methods were published. Details of newly established hepatotoxins as well as updated information on previously documented hepatotoxic drugs is presented. Significant updates in treatment of DILI were also included as well as reports related to global DILI registries.

Drug-induced liver injury (DILI) is a major global health concern resulting from adverse reactions to medications, supplements or herbal medicines. The relevance of DILI has grown with an aging population, the rising prevalence of chronic diseases and the increased use of biologics, including checkpoint inhibitors. This article aims to summarise current knowledge on DILI epidemiology and risk factors.

This review critically appraises available evidence on DILI frequency, outcomes and risk determinants, focusing on drug properties and non-genetic host factors that may influence susceptibility.

DILI incidence varies across populations, with hospitalised patients experiencing notably higher rates than outpatients or the general population. Increased medication use, particularly among older adults and women, may partly explain age- and sex-based disparities in DILI incidence and reporting. Physiological changes associated with aging likely increase susceptibility to DILI in older adults, though further exposure-based studies are needed for definitive conclusions. Current evidence does not strongly support that women are inherently more susceptible to DILI than men; rather, susceptibility appears to depend on specific drugs. However, once DILI occurs, older age and female sex are associated with greater severity and poorer outcomes. Other less-studied host-related risk factors are also discussed based on available evidence.

This article summarises existing data on DILI frequency, outcomes, drug properties affecting hepatotoxicity and non-genetic host risk factors while identifying critical knowledge gaps. Addressing these gaps through future research could enhance understanding and support preventive measures.

Most epidemiological studies have found antibiotics to be the most common cause of drug-induced liver injury (DILI). It is unclear what the risk of DILI is associated with different antibiotics.

The aim of the study was to assess the frequency of DILI due to the most commonly used antibiotics among inpatients, in a population-based setting.

Patients who were treated with the 14 most-used antibiotics at Landspitali University Hospital Iceland 2012-2023, with concomitant: > 5 × upper limit of normal (ULN) of alanine aminotransferase (ALT) and/or > 2 × ULN of alkaline phosphatase (ALP), were identified. If DILI was a potential cause, the Revised Electronic Causality Assessment Method (RECAM) method was used to determine likelihood of DILI.

Overall 2292 patients fulfilled the inclusion criteria, 52 of whom were found to have DILI, median age 67 (range 21-93) years, 58% females, 17 (33%) with jaundice and three (5.8%) died of liver failure. The most commonly implicated agent was amoxicillin/clavulanate (n = 23) in 1:1327 users (0.075%), ceftriaxone (n = 8) 1:3779 (0.02%), cefazolin (n = 7) 1: 6363 (0.016%), cloxacillin 1:6024 (n = 4) (0.017%), piperacillin/tazobactam (n = 2) 1:1551 (0.097%), vancomycin (n = 2) 1:1966 (0.076%), trimethoprim-sulfamethoxazole (TMP/SMX) (n = 3) 1:1096 (0.091%) and ciprofloxacin (n = 1) 1:10,938 (0.009%). In two cases, more than one antibiotic was considered likely.

Drug-induced liver injury was found to be a rare adverse effect of antibiotics in a population-based setting. Overall, 33% presented with jaundice but three died of liver failure, all due to amoxicillin/clavulanate, which was the most common cause occurring in around 1 in 1300 users. However, TMP/SMX was associated with the highest proportional risk of DILI.

The incidence of drug-induced liver injury (DILI) is not known for most prescription medications. We aimed to estimate the incidence of DILI for commonly prescribed outpatient drugs.

To establish a baseline estimate of DILI incidence, we used the estimated incidence (EI) of amoxicillin/clavulanate DILI from a previous population-based study in Iceland. This was combined with the multicenter prospective DILI Network (DILIN) cohort and the US population-based Medical Expenditure Panel Survey (MEPS). From 2005 to 2019, prescription drugs with at least five bona fide DILIN cases and data from at least 10 of the 15 years from MEPS during that timeframe were included. The EI for 'drug A' was calculated as follows: EI ( drug A ) = EI AC × # DILIN cases of drug A # annual new prescriptions of drug A × # annual new prescriptions of AC # DILIN cases of AC RESULTS: In total, 30 drugs met the inclusion criteria, of which 11 were antibiotics, 4 were antiepileptic drugs (AEDs), 4 were statins, and 11 were other drug types. The highest EI was seen with azathioprine and older AEDs, with one DILI case per 349-2329 new prescriptions. The EI of antibiotics ranged greatly, with the highest risk seen for minocycline, amoxicillin/clavulanate, and nitrofurantoin (approximately 1:1000-2400 new prescriptions), and lowest risk for clindamycin, doxycycline, azithromycin, and amoxicillin (approximately 1:40,000-170,000 new prescriptions). The EI for commonly prescribed statins was approximately 1:10,000-50,000. Important medication classes with > 5 million new prescriptions from 2005 to 2019 but fewer than five DILIN cases included β-blockers, thiazide diuretics, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, selective serotonin reuptake inhibitors, and metformin, which presumably have very low DILI incidence.

The highest EI was found for azathioprine, older antiepileptics, and minocycline. In contrast, many widely used drugs are rare causes of DILI. These findings may help clinicians better weigh potential benefits of medications against hepatotoxicity risk.

In the current article the aims for a constructive way forward in Drug-Induced Liver Injury (DILI) are to highlight the most important priorities in research and clinical science, therefore supporting a more informed, focused, and better funded future for European DILI research. This Roadmap aims to identify key challenges, define a shared vision across all stakeholders for the opportunities to overcome these challenges and propose a high-quality research program to achieve progress on the prediction, prevention, diagnosis and management of this condition and impact on healthcare practice in the field of DILI. This will involve 1. Creation of a database encompassing optimised case report form for prospectively identified DILI cases with well-characterised controls with competing diagnoses, biological samples, and imaging data; 2. Establishing of preclinical models to improve the assessment and prediction of hepatotoxicity in humans to guide future drug safety testing; 3. Emphasis on implementation science and 4. Enhanced collaboration between drug-developers, clinicians and regulatory scientists. This proposed operational framework will advance DILI research and may bring together basic, applied, translational and clinical research in DILI.

Checkpoint inhibitors (CPI) account for increasing numbers of drug-induced liver injury (DILI) cases. We aimed to determine the incidence rate and risk factors associated with checkpoint inhibitor-induced liver injury (ChILI).

Prescription event monitoring was performed on all melanoma and renal cancer patients who received CPI at a tertiary centre between 2011 and 2021. ChILI cases were identified using the definitions, grading, and causality assessment methods validated for DILI. We assessed risk factors associated with ChILI in CPI-naive patients using multivariable logistic regression model. Consecutive patients with suspected ChILI from two other tertiary centres were adjudicated and combined for case characterisation and outcomes of ChILI.

Out of 432 patients who received CPI over 10 years, ChILI occurred in 38 (8.8%) with an overall incidence rate of 11.5 per 1,000 person-months (95% CI 8.2-15.8). Probability of ChILI was highest in combination therapy (32%) and no new events occurred beyond 135 days of treatment. Risk factor analysis showed that combination therapy, female sex, higher baseline alanine transferase level and lower baseline alkaline phosphatase level were independently associated with higher risk of ChILI. In total, 99 patients were adjudicated to have ChILI from three centres. Although Common Terminology Criteria for Adverse Events classified 20 patients (20.2%) to have 'life-threatening' grade 4 hepatitis, ChILI severity was graded as mild in 45 (45.5%) and moderate in the remaining 54 (54.5%) cases.

The real-world risk of ChILI is higher than previously reported. Among patients receiving dual CPI, this risk falls markedly after 4.5 months. As Common Terminology Criteria for Adverse Events overestimates its clinical severity, case-definition, evaluation and management of ChILI should be revised to harmonise care.

Using prescription event monitoring over a 10-year period, the incidence rate of checkpoint inhibitor induced liver injury (ChILI) based on established case definitions for drug-induced liver injury (DILI) is 11.5 per 1,000 person-months. Formal causality assessment identified an alternative cause in 19% of patients with suspected ChILI highlighting the importance of systematic evaluation by clinicians to minimise unnecessary immunosuppression. Intensity of monitoring in patients receiving combination therapy regime after 4.5 months of therapy can be reduced as the risk of new onset ChILI beyond this point is minimal. Current Common Terminology Criteria for Adverse Events (CTCAE) grading overestimates clinical severity of ChILI and hence contributes to avoidable hospitalisation.

A lack of biomarkers that detect drug-induced liver injury (DILI) accurately continues to hinder early- and late-stage drug development and remains a challenge in clinical practice. The Innovative Medicines Initiative's TransBioLine consortium comprising academic and industry partners is developing a prospective repository of deeply phenotyped cases and controls with biological samples during liver injury progression to facilitate biomarker discovery, evaluation, validation and qualification.In a nested case-control design, patients who meet one of these criteria, alanine transaminase (ALT) ≥ 5 × the upper limit of normal (ULN), alkaline phosphatase ≥ 2 × ULN or ALT ≥ 3 ULN with total bilirubin > 2 × ULN, are enrolled. After completed clinical investigations, Roussel Uclaf Causality Assessment and expert panel review are used to adjudicate episodes as DILI or alternative liver diseases (acute non-DILI controls). Two blood samples are taken: at recruitment and follow-up. Sample size is as follows: 300 cases of DILI and 130 acute non-DILI controls. Additional cross-sectional cohorts (1 visit) are as follows: Healthy volunteers (n = 120), controls with chronic alcohol-related or non-alcoholic fatty liver disease (n = 100 each) and patients with psoriasis or rheumatoid arthritis (n = 100, 50 treated with methotrexate) are enrolled. Candidate biomarkers prioritised for evaluation include osteopontin, glutamate dehydrogenase, cytokeratin-18 (full length and caspase cleaved), macrophage-colony-stimulating factor 1 receptor and high mobility group protein B1 as well as bile acids, sphingolipids and microRNAs. The TransBioLine project is enabling biomarker discovery and validation that could improve detection, diagnostic accuracy and prognostication of DILI in premarketing clinical trials and for clinical healthcare application.

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.

Diagnosis of drug-induced liver injury (DILI) and its distinction from other liver diseases are significant challenges in drug development and clinical practice. Here, we identify, confirm, and replicate the biomarker performance characteristics of candidate proteins in patients with DILI at onset (DO; n = 133) and follow-up (n = 120), acute non-DILI at onset (NDO; n = 63) and follow-up (n = 42), and healthy volunteers (HV; n = 104). Area under the receiver operating characteristic curve (AUC) for cytoplasmic aconitate hydratase, argininosuccinate synthase, carbamoylphosphate synthase, fumarylacetoacetase, fructose-1,6-bisphosphatase 1 (FBP1) across cohorts achieved near complete separation (range: 0.94-0.99) of DO and HV. In addition, we show that FBP1, alone or in combination with glutathione S-transferase A1 and leukocyte cell-derived chemotaxin 2, could potentially assist in clinical diagnosis by distinguishing NDO from DO (AUC range: 0.65-0.78), but further technical and clinical validation of these candidate biomarkers is needed.