Evaluation of the biliary excretion of pencillin G.

Biliary excretion of penicillin G was studied experimentally by perfusion of isolated rabbit liver. Under these conditions, bile recovery accounted for 5% of the amount of penicillin G added to the perfusing blood (10 mg). In man, after intravenous administration of a 599-mg dose of penicillin G (1,000,000 U) to patients provided with T-tube drainage (n = 10), the maximum biliary level averaged 18.0 +/- 8.0 microgram/ml at 2 h; biliary recovery of penicillin G accounted for 0.12% of the administered dose. The excretion of penicillin G in the juice collected through duodenal tubing in normal subjects averaged 0.07% of the administered dose. Peroperative assays showed that the concentrations determined 1 h after intravenous administration 599 mg of the drug attained 45.7 +/- 16.7 microgram/ml in the gallbladder bile and 93.5 +/- 16.3 microgram/ml in the common-duct bile.