Biliary elimination of aspirin after oral and intravenous administration in patients.

Five patients suffering from various diseases were investigated for biliary elimination of aspirin given i.v. (500 mg, n = 3; 1500 mg, n = 1) or orally (500 mg, n = 2). Two bile draining systems, t-tube and naso-biliary tube, were used to collect the bile fluid. The analysis of biliary secretion of salicylates revealed only small amounts of salicylic acid and its conjugates undergoing biliary elimination and subsequent enterohepatic circulation ranging between 0.02 and 1.89% of the given dose (median 0.18%). Urinary recovery was calculated between 22.4 and 101.78% (median 92.27%). From these data it is concluded that biliary elimination and subsequent enterohepatic circulation plays no (aspirin) or only a minor role (salicylic acid) in the excretion of aspirin in man.