Preoperative cimetidine does not prevent subclinical halothane hepatotoxicity in man

To assess the influence of pretreatment with cimetidine on changes in hepatocellular integrity after halothane anaesthesia, 53 patients were allocated randomly to receive either cimetidine 1600 mg orally or placebo tablets before anaesthesia. Plasma concentrations of glutathione S-transferase (GST) were measured as an index of hepatic damage. Data from 45 patients were available for analysis. Plasma GST concentration increased significantly 3 h after induction of anaesthesia in both groups (P less than 0.01, both groups) and at 6 h in the cimetidine group (P less than 0.05). Pretreatment with cimetidine did not influence the magnitude of increase in GST concentration. There was no difference between the groups in the frequency of abnormal GST concentrations at any time. Cimetidine does not appear to prevent release of GST from the liver by halothane anaesthesia in man.