[Mezlocillin and oxacillin concentrations in the bile of the choledochus]

The purpose of this study was to determine the antibiotic concentrations in serum and bile one and two hours after the completion of a simultaneous short-term infusion of 4 g mezlocillin and 2 g oxacillin. Seven patients were studied. Bile was withdrawn from the bile duct by means of a Teflon catheter. The mean serum concentrations of mezlocillin were 130.4 mg/l and 60.8 mg/l one and two hours after the end of the infusion, respectively. The mean serum concentrations of oxacillin determined at the same times were 57.9 mg/l and 18.9 mg/l, respectively. The mean biliary levels of mezlocillin were 3215.6 mg/l and 2483.1 mg/l one and two hours after the end of the infusion, respectively. The corresponding mean biliary values for oxacillin were 497.3 mg/l and 205.5 mg/l.