[Cefpiramide, a new cephalosporin with high hepatic elimination; experimental evaluation of its biliary passage and disposition in the liver].

The biliary elimination and hepatic disposition of cefpiramide were studied using an isolated and perfused rabbit liver model. Five experiments were performed, each lasting 3 hours. After addition of 10 mg of cefpiramide to the circulating blood, the biliary concentration reached a mean peak of 741 +/- 15 micrograms/ml between the 30th and 60th minute; the cumulated biliary elimination of the drug amounted 4042 +/- 1099 micrograms, corresponding to 40.4% of the injected dose. The hepato-biliary clearance was 54.5 ml/hr and the biliary elimination rate constant 0.2019(hr-1). At the end of the perfusion, 21.7% of the dose was still present in the circulating blood and 1.4% is found in the liver. Control experiments showed that 36.2% of the cefpiramide added into the experimental device was submitted to degradation. Thus, it was possible to calculate the rate of liver biotransformation of cefpiramide, which accounted for 0.3%. These experimental results confirm the major role of the liver in the elimination of cefpiramide and prove that the drug is not submitted to hepatic metabolisation.