[Comparative biliary excretion of mezlocillin and 12 other beta-lactam antibiotics (author's transl)]

The biliary excretion of mezlocillin was studied on an experimental in vitro model (perfused rabbit liver) and by various methods in man. After addition of 10 mg mezlocillin to blood perfusing isolated rabbit lever preparations (n = 5) during 3 hours, a mean biliary peak of 758 +/- 129 micrograms/ml was recorded between 30 and 60 minutes. The 0-3 h cumulative biliary excretion was 20.3 % of the dose administered. Following a 30 min intravenous infusion of 5 g mezlocillin to 5 healthy subjects, the mean maximal antibiotic activity in the duodenal aspiration fluid was 626.0 +/- 115.0 microgram/ml during the first hour. In 10 cholecystectomized patients with T-tube drainage who received 1 g mezlocillin intramuscularly, a mean biliary peak of 296 +/- 58 micrograms/ml was recorded. The 0-12 h cumulative biliary excretion of the antibiotic was 2.6 % of the dose injected. After intravenous infusion of 5 g mezlocillin, the corresponding values were 505 +/- 118 micrograms/ml and 1.3 % respectively. One hour after rapid intravenous injection of 2 g mezlocillin, the antibiotic activities in samples of serum, common bile duct bile and gallbladder bile collected during cholecystectomy were 28.9 +/- 5.3, 895 +/- 196.1 and 402 +/- 133.2 micrograms/ml respectively. These results were compared with those obtained in similar conditions with 12 other beta-lactam antibiotics.