Mezlocillin kinetics in hepatic insufficiency.

To establish elimination kinetics of mezlocillin in patients with hepatic insufficiency, we gave eight normal subjects and four patients with hepatic insufficiency and normal renal function a single 3-gm dose of mezlocillin by intravenous infusion. Subjects with hepatic insufficiency all had serum bilirubins levels of above 3 mg/dl, prothrombin times more than 2 sec longer than control, and creatinine clearances above 60 ml/min. Mezlocillin concentrations were determined by microbiologic assay. Kinetic analysis was by model-independent methods. Elimination half-life was 0.96 hr for subjects with normal liver function and 2.62 hr for patients with hepatic insufficiency. Mean total body clearance for normal subjects was 247 ml/min, while in patients with hepatic insufficiency it was 125.4 ml/min. We conclude that hepatic insufficiency prolongs mezlocillin elimination and suggest that therapeutic guidelines be set up.