Risk Factors for Idiosyncratic Drug-Induced Liver Injury

Idiosyncratic drug-induced liver injury (DILI) is a rare disorder that is not related directly to dosage and little is known about individuals who are at increased risk. There are no suitable preclinical models for the study of idiosyncratic DILI and its pathogenesis is poorly understood. It is likely to arise from complex interactions among genetic, nongenetic host susceptibility, and environmental factors. Nongenetic risk factors include age, sex, and other diseases (eg, chronic liver disease or human immunodeficiency virus infection). Compound-specific risk factors include daily dose, metabolism characteristics, and propensity for drug interactions. Alcohol consumption has been proposed as a risk factor for DILI from medications, but there is insufficient evidence to support this. Many studies have explored genetic defects that might be involved in pathogenesis and focused on genes involved in drug metabolism and the immune response. Multicenter databases of patients with DILI (the United States Drug Induced Liver Injury Network, DILIGEN, and the Spanish DILI registry) are important tools for clinical and genetic research. A genome-wide association study of flucloxacillin hepatotoxicity has yielded groundbreaking results and many similar studies are underway. Nonetheless, DILI is challenging to investigate because of its rarity, the lack of experimental models, the number of medications that might cause it, and challenges to diagnosis.