Drug-induced liver injury is one of the commonest causes for a drug to be withdrawn from the market. In general most drug reactions involving the liver are idiosyncratic and take between 3-8 weeks to develop. Paracetamol is an exception, since it is directly hepatotoxic in overdose, with liver injury being maximal at 3-4 days post ingestion. Paracetamol hepatoxicity may be enhanced by alcohol or anti-epileptic drugs or St John’s Wort. Paracetamol is the commonest cause of acute liver failure in the UK, accounting for >200 cases per year.
Other dugs commonly associated with severe hepatotoxicity include the anti-tuberculous drugs isoniazid and pyrazinamide, as well as co-amoxiclav, NSAIDs, Chinese herbal medicines, and various anti-depressants.