Biliary excretion of cefaclor. Experimental and clinical study.

Biliary excretion of cefaclor, a new orally active cephalosporin, was studied in vitro using an isolated rabbit liver preparation perfused for 3 h (n = 5). Under these conditions, bile recovery amounted to 2.3% of the cefaclor dose added to the circulating blood (10 mg). In humans, after oral administration of a 1-gram dose of cefaclor to cholecystectomized patients provided with a T tube (n = 10), a mean biliary peak concentration of 7.6 +/- 2.4 microgram/ml was observed at the 3rd hour. Cumulative biliary excretion amounted to 0.05% of the administered dose. Assays performed on samples collected during cholecystectomy in 10 patients 1 h after intake of a 1-gram dose of cefaclor showed mean concentrations of 13.7 +- 1.2 micrograms/ml in serum, 8.1 +/- 1.3 micrograms/ml in common duct bile and 5.9 +/- 1.4 micrograms/ml in gallbladder bile. These results were compared with the data obtained after administration of seven other cephalosporins studied under identical conditions.