Kinetics of mezlocillin in patients with biliary t-tube drainage

Abstract

Mezlocillin kinetics were examined in 14 patients with t-tube drainage following biliary surgery. In patients with normal or nearly normal parameters biliary excretion of unchanged drug amounted to 22.1±7.7% ( n = 3) and 14.2%1.95% ( n = 3) respectively of the dose when doses of 2.0 and 4.0 were given intravenously. Patients who had elevated alkaline phosphatase and bilirubin in the plasma excreted no more than 3.2 ± 3.7% ( n = 5) and 6.4±3.6% ( n = 3) respectively of the dose of 2.0 and 4.0 in the bile. Analysis of biliary excretion rates revealed that mezlocillin is excreted in the bile by a step with limited capacity. The apparent β -half-life was not influenced by varying biliary excretion but by renal function and was 87.1 ± 20.8 min irrespectively of the dose. Biliary excretion of the drug was neither related to bile flow rate nor to bilirubin or bile acid output nor to the renal function.