Drugs and the liver

ABSTRACT

Damage to the liver from exposure may be direct or indirect. Direct drug toxicity embraces a wide group of drugs of which the commonest are tetracyclines, alcohol, perhexidine maleate, carbon tetrachloride, methotlrexalte, isoniazid and paracetamol, but could include most poisons and insecticides. These all produce similar toxic changes in the liver, viz. fatty change of hepatocytes with centrizonal fibrosis. Indirect toxicity is an immunological type-related drug toxicity produced by way of toxic metabolites which bind with P450 enzyme systems to produce toxic acetylating agents, the toxicity of which is genetically determined. Prevention is always the preferable course. If direct type sensitivity occurs the offending drug should be discontinued. Support glutathione levels early by L-acetyl-cysteine. Anesthetists must monitor allergic reactions to anesthetics, particularly Halothane, and refrain from frequent unnecessary repetition of the drug otherwise tragic consequences could result. When investigating damage to the liver, renal consequences are often far more important for the patient's survival. (AU)