[Biliary elimination and hepatic disposition of piperacillin: experimental evaluation]

The rate of biliary elimination and the hepatic disposition of piperacillin were studied by using an experimental model of a three hours perfusion of five isolated rabbit liver preparations. After addition of 10 mg of the antibiotic to the circulating blood, a mean biliary peak of 1,013 +/- 305 micrograms/ml was obtained between the 30th and 60th minute. The cumulated biliary elimination (0-3 hr) amounted to 5,665 +/- 389 micrograms (56.7% of the dose given). The hepatobiliary clearance was calculated to 134.2 ml/hr and the biliary elimination rate constant to 0.5 545 (h-1). After the procedure, 7.2 +/- 2.7% of the dose of piperacillin was still present in the circulating blood and 0.4 +/- 0.1% in the liver. The degradation of the antibiotic in the perfusion device concerned 24.9% of the dose. The percentage of piperacillin undergoing hepatic biotransformation, calculated by subtraction, was 10.8%. Under these conditions, the biliary elimination of piperacillin is much higher than that of the twenty other beta-lactams studied in our laboratory by the same experimental procedure.