Is biliary excretion of paracetamol significant in man?

Abstract

The extent of biliary excretion of paracetamol and its principal metabolites was studied in 10 healthy adults. Duodenal intubation was performed approximately 12 h after an oral dose of 1 g paracetamol. Duodenal fluid was aspirated following intravenous cholecystokinin, and urine was collected for 12 h after dosing. The mean concentration of the cysteine and glucuronide conjugates in the bile was 253.7 +/‐ 39.0 micrograms ml‐1 (s.e. mean) and 69.3 +/‐ 15.3 micrograms ml‐1, respectively. The mean recoveries of the cysteine and glucuronide conjugates in the bile were 6.0 +/‐ 1.5 mg and 1.2 +/‐ 0.41 mg, respectively. The bile is an important route of elimination for the cysteine conjugate and accounts for 19.4 +/‐ 4.4% of the total excretion of the metabolite. The fate of the biliary excreted conjugates is not known, and needs further investigation. 1986 The British Pharmacological Society