Hepatotoxicity of drugs and chemicals

Hepatotoxicity of xenobiotics, which include classical drugs, herbal medicines, and chemical products, represents an important cause of liver diseases. Drug hepatotoxicity exhibits various expressions, practically reproducing all non-iatrogenic liver diseases. Drug hepatitis is the main cause of liver failure, in particular with paracetamol overdosage (near 50%). Idiosyncratic hepatitis, which are unpredictable, also represent an important cause with a frequency similar to those of viral hepatitis. More than 1200 drugs are recorded as potential hepatotoxics. Causality assessment relies on chronological and clinical criteria and is frequently difficult. Herbal medicines are an increasing cause of liver injury with a large clinical polymorphism as classical drugs. About 50 plants are known to be hepatotoxic. Diagnosis is even more difficult because of frequent auto-medication and purchase via Internet. Chemical products are also responsible of various liver injuries through variable routes of exposition: inhalation of volatile products, ingestion of contaminating product, percutaneous contamination. Their rote is particularly difficult to assess because exposure is frequently unknown or intermittent or accidental. Liver reaction may occur a long time after exposure, further increasing difficulties of identification. Several tens of chemicals may be involved. There is no specific treatment for xenobiotic hepatotoxicity, once liver injury as occurred apart paracetamol. overdosage. The main measure consists to discontinue this exposition to the responsible compounds to avoid an aggravation of liver injury. (C) 2009 Elsevier Masson SAS. All rights reserved.