Effect of rifampicin on liver function in man.

Liver function and serum concentrations of rifampicin, a highly cholephilic antibiotic, have been studied after ingestion of a single dose of 600 mg of rifampicin in 12 patients, six of them having a normal liver and six a cirrhotic, and during treatment with 600 mg of rifampicin per day for 17 days in eight patients, four of them having a normal liver and four a cirrhotic. Rifampicin produced competition for the elimination of bilirubin and bromsulphalein by the liver. This competition, which seemed to involve mainly the uptake by the liver cell, was always rapidly reversible when treatment was discontinued. It makes it impossible, however, to interpret a bromsulphalein test during treatment with rifampicin. In the eight patients treated for 17 days, apart from the competition already mentioned, no clinical, biological, or morphological abnormalities of the liver were ascertained. But in this limited number of patients it is not possible to exclude the fact that rifampicin could provoke jaundice by idiosyncrasy in a small percentage of cases. The serum concentrations of rifampicin were higher in cirrhotic patients than in patients with normal livers, especially after one or two weeks of treatment. It is suggested that efficient blood concentrations of rifampicin would be achieved with small doses in case of previous hepatocellular insufficiency.