Drug‐induced liver injury

Toxicity is more common at the extremes of age, partly because of increased chances of drug interactions in the elderly and significant co-morbidities. There are also classical age-dependent disorders. Females may be more susceptible to flucloxacillin, methyldopa and nitrofurantoin, while males may be more susceptible to azathioprine and co-amoxiclav cholestatic hepatitis. Not surprisingly, functional polymorphisms are probably important in susceptibility to many drugs. Genetic variation in biliary transport proteins affects susceptibility to cholestatic reactions. Adverse hepatic reactions can mimic a wide spectrum of hepatobiliary diseases. Early recognition and prompt withdrawal of the drug are essential. Failure to detect hepatotoxicity at an early stage may be fatal, and an inaccurate diagnosis may lead to the inappropriate withdrawal of an effective medication. On some occasions, tolerance to idiosyncratic drug-induced liver injury occurs and abnormal liver blood tests and injury resolve despite ongoing therapy (e.g. statin therapy).