Passage of Sulfamethoxazole and Trimethoprim into the Bile in Man

The passage of sulfamethoxazole (SMZ) and trimethoprim (TMP) into the human bile was examined in 10 female patients, who were carriers of a T drain introduced 2–12 days before on the occasion of cholecystectomy. Four of the subjects received a single oral dose of 800 mg SMZ + 160 mg TMP in the form of 2 tablets of Bactrim Roche, three ingested 3 and the remaining three 10 such doses at 12-hour intervals. The concentrations of the drugs in samples of plasma and bile collected at corresponding graded times after medication were then determined. The pharmacokinetic characteristics of the resulting plasma levels lie with few deviations in the normal ranges observed in healthy adults. The content of active SMZ and TMP in the bile is of an order providing very favourable conditions for a curative effect of the combination in cases of biliary infections caused by bacteria sensitive to the two drugs.