Pharmacokinetics of cefoperazone in healthy volunteers

Pharmacokinetics of cefoperazone was studied in 10 healthy volunteers following 15 min intravenous infusion of 2 g. Cefoperazone levels in the blood serum and in the urine were determined microbiologically. At the end of the infusion, mean serum concentrations of the antibiotic were 340.4 (+/- 81.5) mg/l, at the 4th hour after the infusion 38.4 (+/- 10.3) mg/l, and 12 hours after the infusion all subjects had detectable concentrations with the mean value 2.2 (+/- 0.7) mg/l. Within 12 hours, 33.3 (+/- 6.1) % of the total dose of cefoperazone had been eliminated in the urine. The fitting of the individual serum concentration curves and the determination of pharmacokinetic constants were done according to a two-compartment model with the aid of nonlinear least-squares regression analysis on a programmable calculator TI 59. The mean value of the biological half-life (beta phase) of cefoperazone was 1.77 (+/- 0.25) h, mean serum clearance was 61.7 (+/- 12.1) ml/min and the mean distribution volume (Vd area) was 9.44 (+/- 2.2) 1. Our data are in agreement with those previously reported in the literature. The only exception is the distribution volume, which we found to be smaller.