Drug- and Herb-Induced Liver Injury in Clinical and Translational Hepatology: Causality Assessment Methods, Quo Vadis?

Liver function trends in children with suspected drug-induced hepatocellular injury: A survey using an electronic medical records database

BACKGROUND

Drug-induced liver injury (DILI) is a common adverse drug event with limited pediatric data in the literature. This study aimed to use pediatric electronic medical records to assess hepatocellular DILI in pediatric patients who were prescribed liver-injury-inducing drugs.

METHODS

The Pediatric Medical Information Collection System (P-MICS) is a centralized database integrating electronic medical records from over 40 medical pediatric centers. Pediatric patients in the P-MICS with serum alanine aminotransferase (ALT) levels five or more times the upper limit of normal and who were below 15 years of age were selected. Those with liver diseases unrelated to drug-induced causes were excluded. We identified drugs prescribed 2 to 90 days before the first elevated ALT reading. High-risk liver-injury-causing drugs were determined based on the LiverTox score. We analyzed post-event ALT and total bilirubin levels (TB) and DILI management.

RESULTS

Of the 817 patients with suspected DILI, 251 were prescribed four drugs identified as high-risk drugs for hepatocellular DILI: methotrexate (n = 129), aspirin (n = 82), vancomycin (n = 58), and cyclophosphamide (n = 51). The median ALT level at the first event was 245 U/L. Approximately 35% of methotrexate users and cyclophosphamide users experienced recurrent ALT elevation. Some methotrexate users also showed TB elevation. Discontinuation of high-risk drugs resulted in fewer relapses and TB elevations than pharmacotherapy.

CONCLUSIONS

The P-MICS effectively identifies pediatric patients with potential liver injury and tracks liver function in those prescribed liver-injury-causing drugs. This study underscores liver injury risks in pediatric anticancer drug users, highlighting the utility of the P-MICS in monitoring off-label drug safety in children.

Detection of Synergistic Interaction on an Additive Scale Between Two Drugs on Abnormal Elevation of Serum Alanine Aminotransferase Using Machine-Learning Algorithms

Drug-induced liver injury (DILI) is a common adverse drug reaction, with abnormal elevation of serum alanine aminotransferase (ALT). Several clinical studies have investigated whether a combination of two drugs alters the reporting frequency of DILI using traditional statistical methods such as multiple logistic regression (MLR), but this model may over-fit the data. This study aimed to detect a synergistic interaction between two drugs on the risk of abnormal elevation of serum ALT in Japanese adult patients using three machine-learning algorithms: MLR, logistic least absolute shrinkage and selection operator (LASSO) regression, and extreme gradient boosting (XGBoost) algorithms. A total of 58,413 patients were extracted from Nihon University School of Medicine's Clinical Data Warehouse and assigned to case (N = 4,152) and control (N = 54,261) groups. The MLR model over-fitted a training set. In the logistic LASSO regression model, three combinations showed relative excess risk due to interaction (RERI) for abnormal elevation of serum ALT: diclofenac and famotidine (RERI 2.427, 95% bootstrap confidence interval 1.226-11.003), acetaminophen and ambroxol (0.540, 0.087-4.625), and aspirin and cilostazol (0.188, 0.135-3.010). Moreover, diclofenac (adjusted odds ratio 1.319, 95% bootstrap confidence interval 1.189-2.821) and famotidine (1.643, 1.332-2.071) individually affected the risk of abnormal elevation of serum ALT. In the XGBoost model, not only the individual effects of diclofenac (feature importance 0.004) and famotidine (0.016), but also the interaction term (0.004) was included in important predictors. Although further study is needed, the combination of diclofenac and famotidine appears to increase the risk of abnormal elevation of serum ALT in the real world.

Herb-Induced Liver Injury—A Challenging Diagnosis

Herb-induced liver injury (HILI) can be caused by supplements containing herbs, natural products, and products used in traditional medicine. Herbal products’ most common adverse reaction is hepatotoxicity. Almost every plant part can be used to make herbal products, and these products can come in many different forms, such as teas, powders, oils, creams, capsules, and injectables. HILI incidence and prevalence are hard to estimate and vary from study to study because of insufficient large-scale prospective studies. The diagnosis of HILI is a challenging process that requires not only insight but also a high degree of suspicion by the clinician. HILI presents with unspecific symptoms and is a diagnosis of exclusion. For diagnosis, it is necessary to make a causality assessment; the Council for International Organizations of Medical Sciences assessment is the preferred method worldwide. The most effective treatment is the suspension of the use of the suspected herbal product and close monitoring of liver function. The objective of this review is to highlight the necessary steps for the clinician to follow to reach a correct diagnosis of herb-induced liver injury. Further studies of HILI are needed to better understand its complexity and prevent increased morbidity and mortality.

Herb-induced Liver Injury in Asia and Current Role of RUCAM for Causality Assessment in 11,160 Published Cases

Herb-induced liver injuries (HILI) by traditional herbal medicines are particular challenges in Asian countries, with issues over the best approach to establish causality. The aim of the current analysis was to provide an overview on how causality was assessed in HILI cases from Asian countries and whether the Roussel Uclaf Causality Assessment Method (RUCAM) was the preferred diagnostic algorithm, as shown before in worldwide evaluated cases of drug-induced liver injury (DILI). Using the PubMed database, publications in English language were preferred to allow for reevaluation by peers. Overall 11,160 HILI cases have assessed causality using RUCAM and were published by first authors working in Asian countries. With 21 evaluable reports, most publications came from mainland China, with Hong Kong and Taiwan, followed by Korea (n=15), Singapore (n=2), and Japan (n=1), while other Asian countries were not contributory. Most publications provided case and RUCAM data of good quality. For better presentation of future cases, however, the following recommendations are given: (1) preference of prospective study design with use of the updated RUCAM version; (2) clear separation of HILI cohorts from those of other herbal products or DILI; (3) case series for epidemiology studies should contain many essential data, possibly also as supplementary material; (4) otherwise, preference of single case reports providing individual case data and RUCAM-based causality gradings, and applying liver test threshold values; and (5) publication in English language journals. In conclusion, China and Korea are top in presenting RUCAM-based HILI cases, other Asian countries are encouraged to follow.

Agreement Among Different Scales for Causality Assessment in Drug-Induced Liver Injury

BACKGROUND AND OBJECTIVE

The causality assessment of drug-induced liver injury (DILI) remains a challenge and eagerly awaits the development of reliable hepatotoxicity biomarkers. None of the different available algorithms used for the causality assessment of DILI has been universally accepted as the gold standard. This study was conducted to examine the agreement among different causality assessment scales in reporting DILI.

METHODS

The World Health Organization-Uppsala Monitoring Center (WHO-UMC), Naranjo, Roussel Uclaf Causality Assessment Method (RUCAM), Maria & Victorino (M & V) and Digestive Disease Week-Japan (DDW-J) assessment scales were used to compare the causalities in all the reported cases of DILI in our adverse drug reaction (ADR) monitoring centre from January 2014 to June 2017. The probability of the causality assessment was classified as 'definite', 'probable', 'possible' and 'unlikely'. The agreement obtained among the causality assessments was analysed using the weighted kappa (κ _w) test.

RESULTS

A total of 33 cases of DILI were included in our analyses. Anti-tubercular therapy (ATT) and methotrexate were the drugs that most commonly caused DILI. The overall agreement among the different scales was poor. The best agreement was found between RUCAM and DDW-J scales (κ _w: 0.685).

CONCLUSION

There were discrepancies among the different causality scales in assessing DILI. This might be due to the different definitions of causality criteria and subjective variability during assessment. A personalised assessment scale incorporating the latest information on specific risk factors and evidence-based criteria for DILI is warranted.

Systematic Review on Chinese Herbal Medicine Induced Liver Injury

Background. In recent years, with the popularity of CHM, its hepatotoxicity has also been increasingly noticed. However, there are still veils on causative herbs and clinical characteristics. Aim. To systematically review data on CHM induced liver injury with particular focus on causative herbs and clinical characteristics. Methods. Using terms related to CHM and liver injury, PubMed and three Chinese electronic databases were searched, which was limited to the past 5 years. Publications meeting our eligibility criteria were included and further analyzed. Results. In total, 4 single herbs, 21 patent drugs, and 4 decoctions were reported to be of hepatotoxicity, with He-Shou-Wu being the most common one (65/114). Dang-Gui and other 5 herbs were the most common ingredients of patent drugs and decoctions. All patients were assessed using the RUCAM scale, with 26 being highly probable and 28 being probable. For these 54 cases, the latent period was 30 (47) days, and 81.48% were labeled as hepatocellular injuries. Most patients (96.3%) recovered, apart from the fact that one died and one is receiving liver transplantation. Conclusions. CHM should be used carefully for hepatotoxicity. Liver injury from CHM is similar to that from conventional medicines in clinical characteristics. Details about causative herbs should be illustrated, and more RUCAM should be used in future.

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

AIM

Drug-induced liver injury (DILI) is often responsible for acute liver failure, drug withdrawal, boxed warnings or drug non-approval. Therefore, we conducted a case-control study to determine the hepatotoxic risk of a wide range of drugs.

METHODS

The Berlin Case-Control Surveillance Study FAKOS included all 51 Berlin hospitals in a hospital network. Between 2002 and 2011, 198 patients with acute idiopathic hepatitis, 377 inpatient controls and 708 outpatient controls were ascertained. Case patients were thoroughly validated using anamnestic, clinical, laboratory and histological data. Drug exposure was obtained in a face-to-face interview. A possible drug aetiology was assessed in individual patients by applying the updated Council for International Organizations of Medical Sciences (CIOMS) scale. Drug risks were further quantified [odds ratios (OR) with 95% confidence intervals (CI)] in a case-control design with unconditional logistic regression analysis. Drug intake in the last 28 days before index date was considered for the analysis.

RESULTS

The study corroborated hepatotoxic risks for a number of drugs, including phenprocoumon (OR 3.3, 95% CI 1.5, 6.7), amiodarone (OR 5.5, 95% CI 1.3, 21.2), clozapine (OR 34.6, 95% CI 2.8, 824.9) and flupirtine (OR 40.2, 95% CI 5.5, 856.9). Increased risks were also suggested for less commonly reported substances such as angiotensin II receptor blockers, atypical antipsychotics and for biperiden, a drug never before reported to be hepatotoxic.

CONCLUSIONS

Our study identified a large number of drugs as possible causes of hepatotoxicity. The observed risk for seldom reported substances highlights the need for further post-authorization safety studies not exclusively focusing on drugs already labelled as potentially hepatotoxic.

Drug-Induced Liver Injury Network Causality Assessment: Criteria and Experience in the United States

Hepatotoxicity due to drugs, herbal or dietary supplements remains largely a clinical diagnosis based on meticulous history taking and exclusion of other causes of liver injury. In 2004, the U.S. Drug-Induced Liver Injury Network (DILIN) was created under the auspices of the U.S. National Institute of Diabetes and Digestive and Kidney Diseases with the aims of establishing a large registry of cases for clinical, epidemiological and mechanistic study. From inception, the DILIN has used an expert opinion process that incorporates consensus amongst three different DILIN hepatologists assigned to each case. It is the most well-established, well-described and vigorous expert opinion process for DILI to date, and yet it is an imperfect standard. This review will discuss the DILIN expert opinion process, its strengths and weaknesses, psychometric performance and future.

RUCAM in Drug and Herb Induced Liver Injury: The Update

RUCAM (Roussel Uclaf Causality Assessment Method) or its previous synonym CIOMS (Council for International Organizations of Medical Sciences) is a well established tool in common use to quantitatively assess causality in cases of suspected drug induced liver injury (DILI) and herb induced liver injury (HILI). Historical background and the original work confirm the use of RUCAM as single term for future cases, dismissing now the term CIOMS for reasons of simplicity and clarity. RUCAM represents a structured, standardized, validated, and hepatotoxicity specific diagnostic approach that attributes scores to individual key items, providing final quantitative gradings of causality for each suspect drug/herb in a case report. Experts from Europe and the United States had previously established in consensus meetings the first criteria of RUCAM to meet the requirements of clinicians and practitioners in care for their patients with suspected DILI and HILI. RUCAM was completed by additional criteria and validated, assisting to establish the timely diagnosis with a high degree of certainty. In many countries and for more than two decades, physicians, regulatory agencies, case report authors, and pharmaceutical companies successfully applied RUCAM for suspected DILI and HILI. Their practical experience, emerging new data on DILI and HILI characteristics, and few ambiguous questions in domains such alcohol use and exclusions of non-drug causes led to the present update of RUCAM. The aim was to reduce interobserver and intraobserver variability, to provide accurately defined, objective core elements, and to simplify the handling of the items. We now present the update of the well accepted original RUCAM scale and recommend its use for clinical, regulatory, publication, and expert purposes to validly establish causality in cases of suspected DILI and HILI, facilitating a straightforward application and an internationally harmonized approach of causality assessment as a common basic tool.

Reliability of causality assessment for drug, herbal and dietary supplement hepatotoxicity in the Drug-Induced Liver Injury Network (DILIN)

BACKGROUND & AIMS

Because of the lack of objective tests to diagnose drug-induced liver injury (DILI), causality assessment is a matter of debate. Expert opinion is often used in research and industry, but its test-retest reliability is unknown. To determine the test-retest reliability of the expert opinion process used by the Drug-Induced Liver Injury Network (DILIN).

METHODS

Three DILIN hepatologists adjudicate suspected hepatotoxicity cases to one of five categories representing levels of likelihood of DILI. Adjudication is based on retrospective assessment of gathered case data that include prospective follow-up information. One hundred randomly selected DILIN cases were re-assessed using the same processes for initial assessment but by three different reviewers in 92% of cases.

RESULTS

The median time between assessments was 938 days (range 140-2352). Thirty-one cases involved >1 agent. Weighted kappa statistics for overall case and individual agent category agreement were 0.60 (95% CI: 0.50-0.71) and 0.60 (0.52-0.68) respectively. Overall case adjudications were within one category of each other 93% of the time, while 5% differed by two categories and 2% differed by three categories. Fourteen per cent crossed the 50% threshold of likelihood owing to competing diagnoses or atypical timing between drug exposure and injury.

CONCLUSIONS

The DILIN expert opinion causality assessment method has moderate interobserver reliability but very good agreement within one category. A small but important proportion of cases could not be reliably diagnosed as ≥50% likely to be DILI.

Herbal hepatotoxicity in traditional and modern medicine: actual key issues and new encouraging steps

Plants are natural producers of chemical substances, providing potential treatment of human ailments since ancient times. Some herbal chemicals in medicinal plants of traditional and modern medicine carry the risk of herb induced liver injury (HILI) with a severe or potentially lethal clinical course, and the requirement of a liver transplant. Discontinuation of herbal use is mandatory in time when HILI is first suspected as diagnosis. Although, herbal hepatotoxicity is of utmost clinical and regulatory importance, lack of a stringent causality assessment remains a major issue for patients with suspected HILI, while this problem is best overcome by the use of the hepatotoxicity specific CIOMS (Council for International Organizations of Medical Sciences) scale and the evaluation of unintentional reexposure test results. Sixty five different commonly used herbs, herbal drugs, and herbal supplements and 111 different herbs or herbal mixtures of the traditional Chinese medicine (TCM) are reported causative for liver disease, with levels of causality proof that appear rarely conclusive. Encouraging steps in the field of herbal hepatotoxicity focus on introducing analytical methods that identify cases of intrinsic hepatotoxicity caused by pyrrolizidine alkaloids, and on omics technologies, including genomics, proteomics, metabolomics, and assessing circulating micro-RNA in the serum of some patients with intrinsic hepatotoxicity. It remains to be established whether these new technologies can identify idiosyncratic HILI cases. To enhance its globalization, herbal medicine should universally be marketed as herbal drugs under strict regulatory surveillance in analogy to regulatory approved chemical drugs, proving a positive risk/benefit profile by enforcing evidence based clinical trials and excellent herbal drug quality.

Chinese Herbal Medicine-induced Liver Injury

The widespread use of Chinese herbal medicine (CHM) and the associated adverse reactions has attracted the attention of researchers and physicians. Reports have shown that several types of CHM can cause liver injury, with increasing numbers of cases reported every year. The difficulty in characterizing CHM-induced liver injury stems from clinical manifestations, diagnosis and pathogenesis. The clinical manifestations are varied, but gastrointestinal symptoms are the majority. The Council for International Organizations of Medical Sciences scale is currently the most commonly used method for assessing causality in cases of medicine-induced liver injury with excellent sensitivity, specificity and predictive validity. However, the pathogenesis of CHM-induced liver injury is not well understood. The classic view encompasses a contribution from "toxic metabolites" that either elicit an immune response or directly affect cellular biochemical processes or functions. In addition, poor quality and inappropriate clinical use of CHMs contribute to safety concerns. To ensure the safe use of CHMs and decrease the number of hepatotoxic cases, clinicians, researchers and pharmaceutical companies should share responsibility by regulating clinical use, strengthening basic toxicology research and establishing a strict quality control system.

Bicalutamide-induced hepatotoxicity: A rare adverse effect

Patient: Male, 81

Final Diagnosis: Prostate cancer

Symptoms: Anorexia • dark urine • joundice • letargy

Medication: Casodex

Clinical Procedure: —

Specialty: Oncology

Traditional Chinese Medicine Induced Liver Injury

Traditional Chinese Medicine (TCM) is popular around the world and encompasses many different practices with particular emphasis on herbal TCM. Using the PubMed database, a literature search was undertaken to assess the extent herbal TCM products exert rare hepatotoxicity. Analysis of reported cases revealed numerous specified herbal TCM products with potential hepatotoxicity. Among these were An Shu Ling, Bai Fang, Bai Xian Pi, Ban Tu Wan, Bo He, Bo Ye Qing Niu Dan, Bofu Tsu Sho San, Boh Gol Zhee, Cang Er Zi, Chai Hu, Chaso, Chi R Yun, Chuan Lian Zi, Ci Wu Jia, Da Chai Hu Tang, Da Huang, Du Huo, Gan Cao, Ge Gen, Ho Shou Wu, Hu Bohe You, Hu Zhang, Huang Qin, Huang Yao Zi, Hwang Geun Cho, Ji Gu Cao, Ji Ji, Ji Xue Cao, Jiguja, Jin Bu Huan, Jue Ming Zi, Kamishoyosan, Kudzu, Lei Gong Teng, Long Dan Xie Gan Tang, Lu Cha, Ma Huang, Mao Guo Tian Jie Cai, Onshido, Polygonum multiflorum, Qian Li Guang, Ren Shen, Sairei To, Shan Chi, Shen Min, Shi Can, Shi Liu Pi, Shou Wu Pian, Tian Hua Fen, White flood, Wu Bei Zi, Xi Shu, Xiao Chai Hu Tang, Yin Chen Hao, Zexie, Zhen Chu Cao, and various unclassified Chinese herbal mixtures. Causality was firmly established for a number of herbal TCM products by a positive reexposure test result, the liver specific scale of CIOMS (Council for International Organizations of Medical Sciences), or both. Otherwise, the quality of case data was mixed, especially regarding analysis of the herb ingredients because of adulteration with synthetic drugs, contamination with heavy metals, and misidentification. In addition, non-herbal TCM elements derived from Agaricus blazei, Agkistrodon, Antelope, Bombyx, Carp, Fish gallbladder, Phellinus, Scolopendra, Scorpio, and Zaocys are also known or potential hepatotoxins. For some patients, the clinical course was severe, with risks for acute liver failure, liver transplantation requirement, and lethality. In conclusion, the use of few herbal TCM products may rarely be associated with hepatotoxicity in some susceptible individuals, necessitating a stringent pretreatment evaluation of the risk/benefit ratio, based on results of multicenter, randomized, double-blind, placebo-controlled clinical trials.

Drug and herb induced liver injury: Council for International Organizations of Medical Sciences scale for causality assessment

Causality assessment of suspected drug induced liver injury (DILI) and herb induced liver injury (HILI) is hampered by the lack of a standardized approach to be used by attending physicians and at various subsequent evaluating levels. The aim of this review was to analyze the suitability of the liver specific Council for International Organizations of Medical Sciences (CIOMS) scale as a standard tool for causality assessment in DILI and HILI cases. PubMed database was searched for the following terms: drug induced liver injury; herb induced liver injury; DILI causality assessment; and HILI causality assessment. The strength of the CIOMS lies in its potential as a standardized scale for DILI and HILI causality assessment. Other advantages include its liver specificity and its validation for hepatotoxicity with excellent sensitivity, specificity and predictive validity, based on cases with a positive reexposure test. This scale allows prospective collection of all relevant data required for a valid causality assessment. It does not require expert knowledge in hepatotoxicity and its results may subsequently be refined. Weaknesses of the CIOMS scale include the limited exclusion of alternative causes and qualitatively graded risk factors. In conclusion, CIOMS appears to be suitable as a standard scale for attending physicians, regulatory agencies, expert panels and other scientists to provide a standardized, reproducible causality assessment in suspected DILI and HILI cases, applicable primarily at all assessing levels involved.