Assessment of drug-induced liver injury in clinical practice

Secular Trends in Severe Idiosyncratic Drug-Induced Liver Injury in North America: An Update From the Acute Liver Failure Study Group Registry

INTRODUCTION

Idiosyncratic drug-induced liver injury (DILI) is the second leading cause of acute liver failure (ALF) in the United States. Our study aims were to characterize secular trends in the implicated agents, clinical features, and outcomes of adults with DILI ALF over a 20-year period.

METHODS

Among 2,332 patients with ALF enrolled in the ALF Study Group registry, 277 (11.9%) were adjudicated as idiosyncratic DILI ALF (INR ≥ 1.5 and hepatic encephalopathy) through expert opinion. The 155 cases in era 1 (January 20, 1998-January 20, 2008) were compared with the 122 cases in era 2 (January 21, 2008-January 20, 2018).

RESULTS

Among 277 cases of DILI ALF, 97 different agents, alone or in combination, were implicated: antimicrobials, n = 118 (43%); herbal/dietary supplements (HDS), n = 42 (15%); central nervous system agents/illicit substances, n = 37 (13%); oncologic/biologic agents, n = 29 (10%); and other, n = 51 (18%). Significant trends over time included (i) an increase in HDS DILI ALF (9.7% vs 22%, P < 0.01) and decrease in antimicrobial-induced DILI ALF (45.8% vs. 38.5%, P = 0.03) and (ii) improved overall transplant-free survival (23.5%-38.7%, P < 0.01) while the number of patients transplanted declined (46.4% vs 33.6%, P < 0.03).

DISCUSSION

DILI ALF in North America is evolving, with HDS cases rising and other categories of suspect drugs declining. The reasons for a significant increase in transplant-free survival and reduced need for liver transplantation over time remain unclear but may be due to improvements in critical care, increased NAC utilization, and improved patient prognostication.

Familial intrahepatic cholestasis: New and wide perspectives

BACKGROUND

Progressive familial intrahepatic cholestasis (PFIC) includes autosomal recessive cholestatic rare diseases of childhood.

AIMS

To update the panel of single genes mutations involved in familial cholestasis.

METHODS

PubMed search for "familial intrahepatic cholestasis" alone as well as in combination with other key words was performed considering primarily original studies and meta-analyses.

RESULTS

PFIC1 involves ATP8B1 gene encoding for aminophospholipid flippase FIC1. PFIC2 includes ABCB11 gene, encoding for protein functioning as bile salt export pump. PFIC3 is due to mutations of ABCB4 gene responsible for the synthesis of class III multidrug resistance P-glycoprotein flippase. PFIC4 and PFIC5 involve tight junction protein-2 gene and NR1H4 gene encoding for farnesoid X receptor. Benign Intrahepatic Cholestasis, Intrahepatic Cholestasis of Pregnancy and Low-phospholipid-associated cholelithiasis involve the same genes and are characterized by intermittent attacks of cholestasis, no progression to cirrhosis, reversible pregnancy-specific cholestasis and cholelithiasis in young people. Blood and liver tissue levels of bile-excreted drugs can be influenced by the presence of mutations in PFIC genes, causing drug-induced cholestasis. Mutations in PFIC genes might increase the risk of liver cancer.

CONCLUSION

There is a high proportion of unexplained cholestasis potentially caused by specific genetic pathophysiologic pathways. The use of next generation sequencing and whole-exome sequencing could improve the diagnostic process in this setting.

A Rare Case of Ibuprofen-induced Acute Liver Injury

Idiosyncratic drug-induced liver injury (iDILI) is the second-most-common cause of acute liver injury. When it is caused by ibuprofen, it is quite rare, especially when not accompanied by systemic signs or symptoms. A young female patient presented with an ibuprofen overdose suicide attempt and then developed an acute liver injury within a few days. Given its rarity, ibuprofen-induced iDILI was initially a secondary differential, but when her course did not improve as expected, she was quickly evaluated for liver transplant. She fully recovered without needing the transplant, but this case highlights the importance of not only early suspicion/detection but also early referral to a transplant hepatology service.

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.

Drug-Induced Liver Injury Associated with Complementary and Alternative Medicines

A 24-year-old man was admitted due to acute hepatitis with unknown etiology. After his condition and laboratory data gradually improved with conservative therapy, he was discharged 1 month later. Two months after his discharge, however, liver dysfunction reappeared. After his mother accidentally revealed that he took complementary and alternative medicine, discontinuation of the therapy caused his condition to improve. Finally, he was diagnosed with a recurrent drug-induced liver injury associated with Japanese complementary and alternative medicine. It is important to take the medical history in detail and consider complementary and alternative medicine as a cause of liver disease.

Acute Liver Failure after Initiation of Rivaroxaban: A Case Report and Review of the Literature

CONTEXT

Rivaroxaban is a direct factor Xa inhibitor approved for the prevention of thromboembolism. Drug induced liver injury has been increasingly reported with rivaroxaban recently, but actual liver failure has not been reported.

CASE REPORT

We present a case report on the probable occurrence of acute liver failure with rivaroxaban therapy. An 89 year old woman with history of atrial fibrillation was hospitalized for biventricular congestive heart failure with passive congestion of liver, which responded to furosemide. She was discharged home on rivaroxaban for prevention of thrombo-embolism. Liver function tests upon discharge returned to almost normal range. One week later, she presented with abdominal pain and was found to have highly elevated liver enzymes, elevated bilirubin, and an abnormal coagulation profile. A day later, she developed hepatic encephalopathy, suggesting liver failure.

CONCLUSION

Liver enzymes declined rapidly with the discontinuation of all of her medications, however patient died because of multi-organ failure. The causality assessment in this patient was "probable" with rivaroxaban.

The effect of ageing on isoniazid pharmacokinetics and hepatotoxicity in Fischer 344 rats

Isoniazid is the first-line treatment for tuberculosis; however, its use is limited by hepatotoxicity. Age-related differences in isoniazid pharmacokinetics and hepatotoxicity are uncertain. We aimed to investigate these in young (3 ± 0 months, n = 26) and old (23.0 ± 0.2 months, n = 27) male Fischer 344 rats following a low- or high-dose toxic regimen of isoniazid or vehicle (4 doses/day over 2 days; low: 100, 75, 75, 75 mg/kg; high: 150, 105, 105, 105 mg/kg i.p. every 3 h). Fifteen hours after the last dose, animals were euthanized and sera and livers were prepared for analysis. Isoniazid treatment increased serum hepatotoxicity markers (alanine and aspartate transaminase) in young animals but not in old animals, and only reached significance with the high dose in young animals. Isoniazid treatment caused a trend towards an increase in necrosis in young animals with both doses. In contrast, microvesicular steatosis was increased in old isoniazid-treated animals, reaching significance only with the low dose (steatosis prevalence in old: vehicle 1/9, isoniazid 4/5; P < 0.05). Among isoniazid-treated animals, concentrations of toxic intermediates acetylhydrazine and hydrazine were higher in old than young animals (P < 0.05). With both doses, hepatic cytochrome P450 2E1 activity was higher in young animals compared with old (P < 0.05). There were no other age effects seen on any of the other measured enzymes involved in isoniazid metabolism (N-acetyl transferase, amidase, glutathione-S-transferase). These results show age-related changes in isoniazid pharmacokinetics may contribute towards differential patterns of toxicity and confirm that standard hepatotoxicity markers do not detect isoniazid-induced microvesicular steatosis.

Comparison of Liver Biopsy Findings with the Digestive Disease Week Japan 2004 Scale for Diagnosis of Drug-Induced Liver Injury

The liver biopsy remains a valuable tool in the diagnosis of drug-induced liver injury (DILI). The Digestive Disease Week Japan 2004 (DDW-J) scale proposed as an objective tool for the diagnosis of DILI has been widely used in Japan. So far, the histological features have not been compared with DDW-J scale in detail. Herein, we examined the correlation between liver biopsy findings and clinical features, particularly DDW-J scales. A total of 80 patients with liver injuries of unknown cause were enrolled. Based on the histological findings, these cases were categorized into 3 groups: A (DILI was strongly suspected), B (DILI was suspected), and C (DILI should be considered in the differential diagnosis). Histological groups and DDW-J scale were moderately correlated (κ = 0.60). The mean total DDW-J scale scores were as follows: 4.89 for A, 3.26 for B, and 0.75 for C (p < 0.05). While hepatocellular type was coincided in a majority of cases by histological and DDW-J scale evaluation, cholestatic type was not well coincided. In conclusion, biopsy findings and DDW-J scale were well correlated, and the hepatocellular type of liver injuries was well coincided by both evaluations, though there were several discrepant cases, particularly in cholestatic type.

Drug-induced liver disease: Types and mechanisms of action of liver-protecting drugs

Drug-induced liver disease is one of the adverse reactions of clinical drugs. Acute liver injury is the most common form of drug-induced liver disease and even could cause life-threatening liver failure. It is not easy to diagnose, and the diagnosis can be established only after other diagnoses excluded. In most cases, patients usually are prescribed several drugs together, which makes it even harder to distinguish and give standardized treatment. This review summarizes the pathological category of Drug-induced liver disease and the mechanisms of action of liver-protecting drugs.

Late-onset acetaminophen-induced allergic hepatitis with progression to chronicity

Acetaminophen (paracetamol), a widely used antipyretic/analgesic, is a well-known agent causing acute hepatic injury. Whereas most cases are caused by its intrinsic hepatotoxicity, idiosyncratic hepatitis by the allergic mechanism is extremely rare. We herein report a case of late-onset acetaminophen-induced allergic hepatitis with progression to chronicity. This unique case extends the spectrum of acetaminophen-induced liver injury. Clinicians should be aware of this unusual clinical manifestation. The mechanism underlying the immunological reaction to acetaminophen remains to be elucidated.

FXR antagonism of NSAIDs contributes to drug-induced liver injury identified by systems pharmacology approach

Non-steroidal anti-inflammatory drugs (NSAIDs) are worldwide used drugs for analgesic, antipyretic, and anti-inflammatory therapeutics. However, NSAIDs often cause several serious liver injuries, such as drug-induced liver injury (DILI), and the molecular mechanisms of DILI have not been clearly elucidated. In this study, we developed a systems pharmacology approach to explore the mechanism-of-action of NSAIDs. We found that the Farnesoid X Receptor (FXR) antagonism of NSAIDs is a potential molecular mechanism of DILI through systematic network analysis and in vitro assays. Specially, the quantitative real-time PCR assay reveals that indomethacin and ibuprofen regulate FXR downstream target gene expression in HepG2 cells. Furthermore, the western blot shows that FXR antagonism by indomethacin induces the phosphorylation of STAT3 (signal transducer and activator of transcription 3), promotes the activation of caspase9, and finally causes DILI. In summary, our systems pharmacology approach provided novel insights into molecular mechanisms of DILI for NSAIDs, which may propel the ways toward the design of novel anti-inflammatory pharmacotherapeutics.

Profiling cumulative proportional reporting ratios of drug-induced liver injury in the FDA Adverse Event Reporting System (FAERS) database

BACKGROUND

Early prediction and accurate characterization of risk for serious liver injury associated with newly marketed drugs remains an important challenge for clinicians, the pharmaceutical industry, and regulators. To date, a biomarker that specifically indicates exposure to a drug as the etiologic cause of liver injury has not been identified.

OBJECTIVES

Using cumulative proportional reporting ratios (PRRs), we investigated 'real-time' profiles of a set of pharmaceuticals, over the first 3 years of US marketing, for the signaling of clinically serious drug-induced liver injury (DILI) in a large spontaneous-reporting database.

METHODS

Using report counts of hepatic failure or clinically serious liver injury obtained from the FDA Adverse Events Reporting System (FAERS) database, PRRs of adverse drug event terms were calculated by division of counts of domestic reports of these events by counts of all serious adverse events for each of 13 selected drugs associated with a broad range of hepatotoxic risk (including three linked to only rare instances of clinically apparent liver injury) with reference to all other drugs in the database. Drug-specific cumulative PRRs were measured at successive intervals (calendar quarters) using cumulative tallies of FAERS reports to generate time-based profiles over the initial 3 years of US marketing.

RESULTS

In the set of drugs analyzed, those with no known hepatotoxic risk demonstrated time-based cumulative PRR profiles that approximate the background rates of hepatic failure and serious liver injury reported in the entire FAERS database. In contrast, those that were removed from marketing or subjected to marketing restrictions due to their potential to cause liver injury were associated with profiles of rapidly rising cumulative PRRs that were greater than 5 within the first 10 million domestic prescriptions or the first four quarters of US marketing. The systematic tracking and identification of rising PRRs for DILI associated with newly marketed pharmaceutical and biological agents is a valuable tool for identification of safety signals within the FAERS database.

LIMITATIONS

Disproportionality profiling of spontaneous reports in FAERS (e.g., cumulative PRR measurements), which signals an association between a recently marketed drug and liver injury, is not a method to quantitatively measure drug-related risk. Regulatory actions in response to emerging drug safety concerns often depend on an accurate assessment of risks using multiple sources of data and the consideration of overall benefits and risks of the agent. Causality must be determined through analysis of individual cases to exclude other etiologies of liver injury.

CONCLUSION

The FAERS database can be used to advance empiric hepatotoxicity time-trending reporting levels for newly marketed agents in order to rapidly identify recently launched potential hepatotoxic agents and initiate further evaluation.

Antibiotic induced liver injury: what about children?

Antimicrobial agents are important causes of drug-induced liver injury. They are responsible for about 45% of cases of drug hepatotoxicity. Hepatic damage mechanisms are intrinsic or idiosyncratic. Usually, antibiotics are responsible for idiosyncratic toxicity. This review summarizes the rate of incidence and clinical features of hepatotoxicity due to antibiotics and chemotherapics, with particular attention to data regarding paediatric population. Liver injury features have been systematically evaluated for the most commonly administered antibiotics and chemotherapics in adults, even though there is little information about other widely used compounds, as cephalosporine or clarithromycin, and about antibiotics active against multi-resistant bacteria, as carbapenems, vancomycin, clindamycin, and linezolid. By contrast, there is an abundance of case reports in paediatrics, but very few structured studies have been carried out in children. Children are an important class of antibiotic users, with specific metabolic characteristics, so more studies on them should be carried out.

Idiopathic acute liver injury in paediatric outpatients: incidence and signal detection in two European countries

BACKGROUND

Acute liver failure is idiopathic and drug-related in, respectively, around 50 and 15 % of children. Population-based, epidemiologic data about the pattern of disease manifestation and incidence of less severe acute liver injury, either idiopathic or potentially drug-attributed are limited in children and adolescents.

OBJECTIVES

(i) To assess the incidence of idiopathic acute liver injury (ALI) and its clinical features in children and adolescent outpatients; and (ii) to investigate the role of the drug as a potential cause of ALI which is considered idiopathic.

METHODS

A retrospective cohort study was performed during the years 2000-2008. Data were retrieved from three longitudinal electronic healthcare databases in two European countries: Pedianet and Health Search/CSD Longitudinal Patient Database from Italy and the Integrated Primary Care Information database from The Netherlands. Cases of idiopathic acute liver injury in population aged <18 years were identified by exclusion of all competing causes of liver injury (e.g. viral, autoimmune hepatitis), according to CIOMS criteria. The potential role of drug exposure as actual underlying cause of idiopathic ALI was detected through signal detection mining techniques. Both pooled and country-specific incidence rates [IR/100,000 person-years (PYs)] of idiopathic ALI and pooled adjusted rate ratios (RR) of drugs identified as a potential cause of idiopathic ALI, plus 95 % confidence intervals (CI) were estimated using the custom-built software Jerboa.

RESULTS

Among 785 definite cases of idiopathic ALI, the pooled IR was 62.4/100,000 PYs (95 % CI 58.1-66.8). The country-specific IR was higher in Italy (73.0/100,000 PYs, 95 % CI 67.8-78.4) than in The Netherlands (21.0/100,000 PYs, 95 % CI 16.0-27.2) and increased with age in both countries. Isolated elevations of liver enzymes were reported in around two-thirds of cases in Italy, while in The Netherlands the cases were more often identified by a combination of signs/symptoms. Among drugs detected as potential underlying cause of idiopathic ALI, clarithromycin (RR 25.9, 95 % CI 13.4-50), amoxicillin/clavulanic acid (RR 18.6, 95 % CI 11.3-30.6), and amoxicillin (RR 7.5, 95 % CI 3.4-16.8) were associated with the highest risk compared to non-use.

CONCLUSION

The incidence of idiopathic ALI in paediatrics is relatively low and comparable with adults. Clinical presentations differ between the two European countries. Signal detection in healthcare databases allowed identifying antibiotics as the drugs mostly associated with ALI with apparently unknown aetiology.

A detection algorithm for drug-induced liver injury in medical information databases using the Japanese diagnostic scale and its comparison with the Council for International Organizations of Medical Sciences/the Roussel Uclaf Causality Assessment Method scale

PURPOSE

Drug-induced liver injury (DILI) is one of the primary targets for pharmacovigilance using medical information databases (MIDs). Because of diagnostic complexity, a standardized method for identifying DILI using MIDs has not yet been established. We applied the Digestive Disease Week Japan 2004 (DDW-J) scale, a Japanese clinical diagnostic criteria for DILI, to a DILI detection algorithm, and compared it with the Council for International Organizations of Medical Sciences/the Roussel Uclaf Causality Assessment Method (CIOMS/RUCAM) scale to confirm its consistency. Characteristics of DILI cases identified by the DDW-J algorithm were examined in two Japanese MIDs.

METHODS

Using an MID from the Hamamatsu University Hospital, we constructed a DILI detection algorithm on the basis of the DDW-J scale. We then compared the findings between the DDW-J and CIOMS/RUCAM scales. We examined the characteristics of DILI after antibiotic treatment in the Hamamatsu population and a second population that included data from 124 hospitals, which was derived from an MID from the Medical Data Vision Co., Ltd. We performed a multivariate logistic regression analysis to assess the possible DILI risk factors.

RESULTS

The concordance rate was 79.4% between DILI patients identified by the DDW-J and CIOMS/RUCAM; the Spearman rank correlation coefficient was 0.952 (P < 0.0001). Men showed a significantly higher risk for DILI after antibiotic treatments in both MID populations.

CONCLUSIONS

The DDW-J and CIOMS/RUCAM algorithms were equivalent for identifying the DILI cases, confirming the utility of our DILI detection method using MIDs. This study provides evidence supporting the use of MID analyses to improve pharmacovigilance.

Female gender as a susceptibility factor for drug-induced liver injury

Adverse drug reactions (ADRs) can involve all tissues and organs, but liver injuries are considered among the most serious. A number of prospective, multicenter studies have confirmed a higher risk of ADRs in general among female subjects compared to a male cohort. Although drug-induced liver injury (DILI) is infrequently encountered, the preponderance of evidence suggests that women appear to be more susceptible than men to fulminate hepatic/acute liver failure especially in response to some anti-infective drugs and to autoimmune-like hepatitis following exposure to certain other therapeutic drugs. A number of hypotheses have been proposed to explain this sex difference in susceptibility to DILI. Collectively, these hypotheses suggest three basic sex-dependent mechanisms that include differences in various aspects of drug pharmacokinetics (PK) or pharmacodynamics following the administration of certain drugs; specific hormonal effects or interactions with immunomodulating agents or signaling molecules; and differences in the adverse response of the immune system to some drugs, reactive drug metabolites, or drug-protein adducts. At the preclinical drug safety stage, there is a need for more research on hormonal effects on drug PK and for additional research on gender differences in aberrant immune responses that may lead to idiosyncratic DILI in some female patients. Because the detection of rare but serious hepatic ADRs requires the exposure of very large patient populations, pharmacovigilance networks will continue to play a key role in the postmarketing surveillance for their detection and reporting.

Autoimmune hepatitis: a noninfectious killer

PURPOSE

This article reviews autoimmune hepatitis (AIH) to promote early recognition, diagnosis, and referral for nurse practitioners (NPs) encountering this rare condition.

DATA SOURCES

Selected research and clinical articles from Medline, PubMed, and CINAHL.

CONCLUSIONS

AIH is a rare condition of unknown etiology affecting women 3.6 times more than men and may result in liver failure, subsequent liver transplantation, and death. Untreated AH is associated with up to 80% mortality. Collaboration and referral to gastroenterologists, hepatologists, and other specialists are needed to improve outcomes for this potentially devastating disease.

IMPLICATIONS FOR PRACTICE

Corticosteroid treatment has long been the mainstay of treatment of AIH, although newer therapies are promising. NPs can dramatically improve outcomes by early recognition, diagnosis, referral, and monitoring for common side effects of treatment working collaboratively with specialists.

Efficacy and Safety Evaluation of a Large Niacin Therapeutic Interchange Program

BACKGROUND

An extended-release niacin product (Niaspan, Abbott Laboratories) was identified as a product with a less costly therapeutic alternative; a therapeutic product interchange was implemented.

OBJECTIVE

To evaluate the efficacy and safety of a product therapeutic interchange from Niaspan to a controlled-release niacin product (Slo-Niacin, Upsher-Smith Laboratories) among patients at a large US Department of Veterans Affairs health care facility.

METHODS

Patients with active prescriptions for Niaspan underwent a therapeutic product interchange to Slo-Niacin; following conversion of the product, the medical record for each patient was reviewed and pre- and postconversion clinical information and conversion details were transcribed into a database for subsequent analysis and study. The primary efficacy end point was pre- and postconversion level of low-density lipoprotein cholesterol; secondary efficacy end points were levels of serum total cholesterol, high-density lipoprotein cholesterol, and triglycerides. Abnormal serum liver enzyme levels greater than 3 times the upper limits of normal was the primary safety end point; blood hemoglobin A1c was assessed as a secondary safety end point.

RESULTS

A total of 5321 patients' medical records were reviewed; for the efficacy evaluation, 539 patients were maintained on a daily dose of Slo-Niacin that was the same as the previous Niaspan dose. The dosage of any other concurrently prescribed dyslipidemia medication was unchanged. Analysis of these cases indicated that the conversion of Niaspan to Slo-Niacin was not associated with a difference in serum lipids over a mean (SD) of 503.9 (98.0) postconversion observation days with the exception of a decrease in mean serum triglyceride concentration of 19.8 mg/dL (p = 0.0003). Evaluation of all 5321 patients given Slo-Niacin for up to 724 days did not detect any safety differences between Slo-Niacin and Niaspan. Local facility cost avoidance exceeded $800,000 in the first postconversion year.

CONCLUSIONS

Data from a medication use evaluation of modified-release niacin products therapeutic interchange in a large US Department of Veterans Affairs health care facility show that the switch from Niaspan to Slo-Niacin had no negative effects on lipid-altering efficacy or safety but generated significant cost avoidance.

Drug-Induced Liver Injury: Twenty Five Cases of Acute Hepatitis Following Ingestion of Polygonum multiflorum Thunb

Background/Aims

Complementary medicines, including herbal preparations and nutritional supplements, are widely used without prescriptions. As a result, there has been growing interest in the risk of hepatotoxicity with these agents. It is difficult to determine causal relationships between these herbal preparations and hepatotoxicity. We report on 25 patients diagnosed with toxic hepatitis following ingestion of Polygonum multiflorum Thunb.

Methods

Twenty-five patients (median age, 48 years [24 to 65 years]; M:F=18:7) with suspected P. multiflorum Thunb-induced liver injury were admitted to our hospital between 2007 and 2009. We analyzed clinical and histological data, including the types and the duration of P. multiflorum Thunb intake and the duration of hospital care. We also determined the type of liver injury using the R ratio (serum activity of ALT/serum activity of ALP).

Results

The types of complementary medicine used included tea (n=16), liquor (n=5), tea and liquor (n=2), powder (n=1), and honeyed pudding (n=1). The most common presenting sign was jaundice (76%), and 18 patients (72%) had evidence of hepatocellular liver injury. Histological findings were consistent with acute hepatitis in all cases (n=10) for which liver biopsy was performed. Twenty-three patients (91.6%) recovered with conservative management, 1 patient (4%) had a liver transplant, and 1 patient (4%) died of hepatic failure.

Conclusions

In our cases, we found that P. multiflorum Thunb could be hepatotoxic and could lead to severe drug-induced liver injury, and even death.

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.

Accuracy and reproducibility of two scales in causality assessment of unexpected hepatotoxicity

WHAT IS KNOWN AND OBJECTIVE

There is almost no published information about reliability of scales for causality assessment in hepatotoxicity at pharmacovigilance centres. The aim of this study was to compare two commonly used scales in cases of unexpected hepatotoxicity, in evaluating their accuracy and reproducibility at pharmacovigilance centres (in signal detection).

METHODS

Two scales [Council for International Organizations of Medical Sciences or Rousel Uclaf Causality Assessment Method (CIOMS/RUCAM) and NARANJO] were compared in 19 cases of unexpected hepatotoxicity reported during 2004-2009. Data of the cases (with initial clinical assessments) were collected by a network of medical specialists using a structured reporting form. Later, two independent observers assessed each case using both scales. The accuracy and reproducibility of the scales were analysed by Kappa weighted (Kw) test.

RESULTS

  Both scales (CIOMS/RUCAM vs. NARANJO) showed moderate agreement with the initial clinical assessments (accuracy) for observer A (Kw: 0·56 vs. 0·60) and substantial agreement for observer B (Kw: 0·72 vs. 0·70), with high agreement between observers (Kw: 0·84 vs. 0·67). Both observers (A vs. B) found low agreement between scales (Kw: 0·21 vs. 0·50), with lower scores for the CIOMS/RUCAM scale in 11 and nine cases, respectively. For an early perception of unexpected serious reactions, the scale is more useful if it is not asked for 'previous knowledge' and if it gives higher causality score.

WHAT IS NEW AND CONCLUSION

The CIOMS/RUCAM scale showed similar accuracy, but better reproducibility (agreement between observers) than the NARANJO scale, and therefore is recommended for use at pharmacovigilance centres. Fine-tuning of the CIOMS/RUCAM method could contribute to better detection of unexpected hepatotoxicity.

Consistency between causality assessments obtained with two scales and their agreement with clinical judgments in hepatotoxicity

PURPOSE

Reliability and usefulness of scales for causality assessment in hepatotoxicity have not been fully explored. The goal of this study was to examine consistency between causality assessments obtained with two commonly used scales and their agreement with initial clinical assessments in hepatotoxicity reported in Serbia, and to review usefulness of these scales.

METHODS

We compared the two scales (CIOMS/RUCAM and NARANJO) in 80 cases reported during 1995-2009. The initial clinical assessments performed at the time of reporting served as a control for comparison with the subsequent causality assessments. The agreement between obtained causality assessments and the initial clinical assessments were analysed by Kappa weighted (K(w)) statistical test.

RESULTS

In the 80 cases, the NARANJO scale showed better agreement with the initial clinical assessments (K(w): 0.62) than the CIOMS/RUCAM scale (K(w): 0.50) with moderate mutual agreement (K(w): 0.58). Results for 69 cases reported before the start of the study showed the same. In 11 cases reported in 2009 (after the start of the study) the CIOMS/RUCAM scale showed better agreement with the initial clinical assessments (K(w): 0.80) than the NARANJO scale (K(w): 0.70) with perfect mutual agreement (K(w): 1.0).

CONCLUSION

The two scales showed good similarity and the same was true when their outcomes were compared with the clinical judgments provided by the reporting physicians. Both scales may be useful in pharmacovigilance and clinical practice, but the CIOMS/RUCAM scale provides more specific data. Our results also confirmed that the quality of data and documentation influence the reliability of the method.

Evaluation of hepatotoxicity with off-label oral-treatment doses of voriconazole for invasive fungal infections

The approved treatment dose of intravenous voriconazole is a weight-based dose of 4 mg/kg of body weight twice daily; the approved oral dosing is fixed at 200 mg twice daily. In our institution, patients frequently receive oral high-dose voriconazole at 4 mg/kg twice daily. It is unknown if higher doses are associated with increased hepatotoxicity. A retrospective cohort study of patients treated with oral voriconazole for presumed invasive fungal infection for ≥7 days was completed. Patients receiving a fixed dose (i.e., labeled dose) were frequency matched and compared to those receiving a weight-based dose (i.e., high dose). The primary endpoint of hepatotoxicity was evaluated by using NCI Common Terminology Criteria (CTC) and components of liver enzymes measuring >3× the upper limit of normal (ULN) and >5× baseline measurements. Secondary endpoints included an incidence of other adverse drug events. Twenty-five labeled-dose and 84 high-dose voriconazole patients were studied. Liver enzyme abnormalities were similar between groups, with the exception of labeled-dose patients experiencing more alkaline phosphatase (ALP) CTC >2× the baseline (P = 0.02) and ALP levels >3× the ULN (P = 0.02). Treatment with high dose was associated with the discontinuation of voriconazole for practitioner attribution of adverse drug events (P = 0.03), although reasons varied and no commonality of biomarker abnormality was identified. Multivariate analysis revealed that the duration of therapy and higher mg/kg total daily doses as interval variables were predictive of some hepatotoxicity outcomes. No difference existed in liver abnormalities for high-dose voriconazole; however, higher mg/kg doses and a longer duration of therapy may be associated with hepatotoxicity.

Drugs associated with hepatotoxicity and their reporting frequency of liver adverse events in VigiBase: unified list based on international collaborative work

BACKGROUND

Challenges exist in the clinical diagnosis of drug-induced liver injury (DILI) and in obtaining information on hepatotoxicity in humans.

OBJECTIVE

(i) To develop a unified list that combines drugs incriminated in well vetted or adjudicated DILI cases from many recognized sources and drugs that have been subjected to serious regulatory actions due to hepatotoxicity; and (ii) to supplement the drug list with data on reporting frequencies of liver events in the WHO individual case safety report database (VigiBase).

DATA SOURCES AND EXTRACTION

(i) Drugs identified as causes of DILI at three major DILI registries; (ii) drugs identified as causes of drug-induced acute liver failure (ALF) in six different data sources, including major ALF registries and previously published ALF studies; and (iii) drugs identified as being subjected to serious governmental regulatory actions due to their hepatotoxicity in Europe or the US were collected. The reporting frequency of adverse events was determined using VigiBase, computed as Empirical Bayes Geometric Mean (EBGM) with 90% confidence interval for two customized terms, 'overall liver injury' and 'ALF'. EBGM of >or=2 was considered a disproportional increase in reporting frequency. The identified drugs were then characterized in terms of regional divergence, published case reports, serious regulatory actions, and reporting frequency of 'overall liver injury' and 'ALF' calculated from VigiBase.

DATA SYNTHESIS

After excluding herbs, supplements and alternative medicines, a total of 385 individual drugs were identified; 319 drugs were identified in the three DILI registries, 107 from the six ALF registries (or studies) and 47 drugs that were subjected to suspension or withdrawal in the US or Europe due to their hepatotoxicity. The identified drugs varied significantly between Spain, the US and Sweden. Of the 319 drugs identified in the DILI registries of adjudicated cases, 93.4% were found in published case reports, 1.9% were suspended or withdrawn due to hepatotoxicity and 25.7% were also identified in the ALF registries/studies. In VigiBase, 30.4% of the 319 drugs were associated with disproportionally higher reporting frequency of 'overall liver injury' and 83.1% were associated with at least one reported case of ALF.

CONCLUSIONS

This newly developed list of drugs associated with hepatotoxicity and the multifaceted analysis on hepatotoxicity will aid in causality assessment and clinical diagnosis of DILI and will provide a basis for further characterization of hepatotoxicity.

Adverse drug reactions to antiretroviral therapy (ART): an experience of spontaneous reporting and intensive monitoring from ART centre in India

PURPOSE

To assess the nature, severity, predictability and preventability of adverse drug reactions (ADRs) and to identify risk factors for antiretroviral ADRs.

METHODS

Enrolled ambulatory patients were intensively monitored for ADRs. Spontaneously reported ADRs by clinicians were also included. Predictability was assessed based on history of previous exposure to the drug or literature incidence of ADRs. Preventability was assessed using Schumock and Thornton criteria and severity was assessed using modified Hartwig and Siegel scale. Bivariate analysis and subsequently multivariate logistic regression were used to identify the risk factors for ADRs. Data from spontaneous reporting was assessed using Bayesian neural network method for possible ADR signals.

RESULTS

Monitoring by active surveillance indentified 159 (52.82%) ADRs from 400 patients. One hundred and forty-two (47.17%) reactions were spontaneously reported. Anaemia and vomiting were the most commonly observed ADRs. The ADRs were severe in 10.9% of cases. A total of 88% ADRs were definitely/probably preventable. Use of Zidovudine+Lamivudine with Nevirapine or Efavirenz, CD4 <200 cells/microl, female gender, tuberculosis and illiteracy were observed as risk factors for ADRs by bivariate analysis. Concurrent tuberculosis was the only influential risk factor for development of ADRs identified by multivariate logistic regression.

CONCLUSION

Prevalence of ADRs in intensively monitored patients was found to be 39.7%. Tuberculosis in HIV patients is an influential risk factor for occurrence of ADRs. With the increasing access to antiretrovirals in India, ADRs to antiretrovirals require monitoring and reporting.

Prospective drug safety monitoring using the UK primary-care General Practice Research Database: theoretical framework, feasibility analysis and extrapolation to future scenarios

BACKGROUND

Post-launch drug safety monitoring is essential for the detection of adverse drug signals that may be missed during preclinical trials. Traditional methods of postmarketing surveillance such as spontaneous reporting have intrinsic limitations, many of which can be overcome by the additional application of structured pharmacoepidemiological approaches. However, further improvement in drug safety monitoring requires a shift towards more proactive pharmacoepidemiological methods that can detect adverse drug signals as they occur in the population.

OBJECTIVE

To assess the feasibility of using proactive monitoring of an electronic medical record system, in combination with an independent endpoint adjudication committee, to detect adverse events among users of selected drugs.

METHODS

UK General Practice Research Database (GPRD) information was used to detect acute liver disorder associated with the use of amoxicillin/clavulanic acid (hepatotoxic) or low-dose aspirin (acetylsalicylic acid [non-hepatotoxic]). Individuals newly prescribed these drugs between 1 October 2005 and 31 March 2006 were identified. Acute liver disorder cases were assessed using GPRD computer records in combination with case validation by an independent endpoint adjudication committee. Signal generation thresholds were based on the background rate of acute liver disorder in the general population.

RESULTS

Over a 6-month period, 8148 patients newly prescribed amoxicillin/clavulanic acid and 5577 patients newly prescribed low-dose aspirin were identified. Within this cohort, searches identified 11 potential liver disorder cases from computerized records: six for amoxicillin/clavulanic acid and five for low-dose aspirin. The independent endpoint adjudication committee refined this to four potential acute liver disorder cases for whom paper-based information was requested for final case assessment. Final case assessments confirmed no cases of acute liver disorder. The time taken for this study was 18 months (6 months for recruitment and 12 months for data management and case validation). To reach the estimated target exposure necessary to raise or rule out a signal of concern to public health, we determined that a recruitment period 2-3 times longer than that used in this study would be required. Based on the real market uptake of six commonly used medicinal products launched between 2001 and 2006 in the UK (budesonide/eformoterol [fixed-dose combination], duloxetine, ezetimibe, metformin/rosiglitazone [fixed-dose combination], tiotropium bromide and tadalafil) the target exposure would not have been reached until the fifth year of marketing using a single database.

CONCLUSION

It is feasible to set up a system that actively monitors drug safety using a healthcare database and an independent endpoint adjudication committee. However, future successful implementation will require multiple databases to be queried so that larger study populations are included. This requires further development and harmonization of international healthcare databases.

Fatal hepatic and renal toxicity as a complication of trabectedin therapy for radiation-induced sarcoma

Trabectedin therapy was prescribed for a patient with radiation-induced sarcoma. Two doses of trabectedin were given before therapy was discontinued with the patient experiencing renal and liver failure. Despite discontinuing trabectedin the patient continued to experience increases in liver transaminases, bilirubin, blood urea nitrogen, and serum creatinine. Hemodialysis was initiated with no improvement. With all other causes being ruled out, trabectedin likely caused hepatic and renal failure leading to death in this patient. Recent literature suggests that patients may benefit from prophylactic dexamethasone as a means of reducing hepatic toxicity.

Drug-induced liver injury: what was new in 2008?

BACKGROUND

Given the number of publications appearing annually regarding drug-induced liver injury (DILI), there remains a need to concisely summarize each year's new crop of case series and reports as well as the advances in mechanisms of liver injury and in the field of pharmacogenomics relating to DILI.

OBJECTIVE

To present an up-to-date review of the past year's most important clinical studies and reports of DILI, placing them into context of previous publications.

METHODS

A Medline search was conducted of all manuscripts appearing in the fields "hepatotoxicity" and "drug-induced liver injury" during the calendar year 2008. The most clinically relevant English language case reports and studies exploring mechanisms and risk factors for DILI were then chosen for review, and supplemented with older literature where appropriate.

CONCLUSIONS

As in past years, 2008 was replete with publications dealing with virtually all facets of DILI, including updated incidence and prevalence data, as well as the latest information regarding mechanisms of liver injury. Data from the first 300 patients in the National Institute of Health-sponsored DILI Network registry of > 100 non-acetaminophen causes were presented. Antimicrobials and CNS drugs were responsible for > 60% of cases, with herbals and dietary supplements being increasingly reported. Identification of genetic predispositions to DILI is coming of age with the FDA calling for the testing of human leukocyte antigen B(*)5701 before the use of abacavir to reduce the risk of hypersensitivity reactions. Several groups emphasized the pitfalls in utilizing Roussel Uclaf Causality Assessment Method and other causality assessment methodologies, and an updated review appeared on the use of potentially hepatotoxic medications in patients with underlying liver disease.

Use of cassette dosing in sandwich-cultured rat and human hepatocytes to identify drugs that inhibit bile acid transport

Hepatocellular accumulation of bile acids due to inhibition of the canalicular bile salt export pump (BSEP/ABCB11) is one proposed mechanism of drug-induced liver injury (DILI). Some hepatotoxic compounds also are potent inhibitors of bile acid uptake by Na(+)-dependent taurocholate cotransporting polypeptide (NTCP/SLC10A1). This study used a cassette dosing approach in rat and human sandwich-cultured hepatocytes (SCH) to determine whether known or suspected hepatotoxic drugs inhibit bile acid transport individually or in combination. [(3)H]-Taurocholate served as the NTCP/BSEP probe substrate. Individually, cyclosporin A and rifampin decreased taurocholate in vitro biliary clearance (Cl(biliary)) and biliary excretion index (BEI) by more than 20% in rat SCH, suggesting that these drugs primarily inhibited canalicular efflux. In contrast, ampicillin, carbenicillin, cloxacillin, nafcillin, oxacillin, carbamazepine, pioglitazone, and troglitazone decreased the in vitro Cl(biliary) by more than 20% with no notable change in BEI, suggesting that these drugs primarily inhibited taurocholate uptake. Cassette dosing (n=2-4 compounds per cassette) in rat SCH yielded similar findings, and results in human SCH were consistent with rat SCH. In summary, cassette dosing in SCH is a useful in vitro approach to identify compounds that inhibit the hepatic uptake and/or excretion of bile acids, which may cause DILI.

Gastrointestinal side effects of prescription medications in the older adult

Gastrointestinal (GI) symptoms resulting from either prescription medications or over-the-counter drugs are frequently encountered in geriatric practice but often mistaken for symptoms of an organic disease leading to multiple diagnostic studies. The morbidity, mortality, and medical costs associated with drug toxicity, even when restricted to the GI tract, are probably underestimated. The consequences of drug toxicity are quite variable and range from a symptom of mild discomfort (eg, drug-induced diarrhea) at one end of the spectrum, to fatal GI hemorrhage or perforation. Better awareness of the possibility of drug-induced GI tract pathology by primary care physicians improves the recognition of these adverse effects, and ultimately, improves patient care. This review focuses on the most common and well-described drug-related side effects of the GI tract.

Review article: The use of potentially hepatotoxic drugs in patients with liver disease

BACKGROUND

Misconceptions surround the use of hepatotoxic drugs in chronic liver disease. While many prescription and over-the-counter (OTC) agents can be used safely, this often runs counter to labelled warnings/contraindications, especially for the statins and other commonly used agents.

AIM

To evaluate published data on the use of hepatotoxic drugs in chronic liver disease including pharmacokinetic changes in cirrhosis and drug interactions, where available, to formulate recommendations on their use.

METHODS

Using a combination of PubMed searches, review texts, the Physicians' Desk Reference and expert opinion, drugs considered at higher risk of hepatotoxicity in chronic liver disease were evaluated.

RESULTS

Most drugs and OTC products including herbals have not been formally studied in chronic liver disease, but available data suggest that several of the most commonly used agents, especially the statins, can be used safely. While there is an increased risk of drug-induced liver injury for drugs used in the treatment of tuberculosis and HIV patients with hepatitis B or C, recommendations for their safe use are emerging.

CONCLUSIONS

Although many clinicians remain hesitant to use hepatotoxic drugs in chronic liver disease, the database supporting this view is limited to just a few agents. Most medications can be used safely in patients with chronic liver disease with appropriate monitoring.