Effect of rifampicin treatment on hepatic drug metabolism and serum bile acids in patients with primary biliary cirrhosis.

Six patients with primary biliary cirrhosis (PBC) were treated with a daily oral dose of 600 mg rifampicin for 2 weeks to induce the hepatic metabolism of drugs and bile acids. On rifampicin 5 of 6 patients experienced a pronounced decrease of their pruritus. In all patients the oxidative cytochrome P-450 dependent drug metabolism was induced as shown by an increase of antipyrine-clearance from 36.3 +/- 8.8 to 80.6 +/- 20.1 ml/min and an enhanced urinary excretion of 6-beta-hydroxycortisol from 454 +/- 1.99 to 1607 +/- 362 micrograms/24 h. Furthermore, in all 6 patients the serum alkaline phosphatase declined. In the 3 cholestatic patients (bilirubin greater than 1.0 mg/dl) the serum concentration of total and conjugated bile acids was strikingly reduced. Thus, rifampicin is an inducer of hepatic metabolism in PBC-patients, ameliorates the pruritus and can lower serum concentrations of alkaline phosphatase and bile acids.