[HPLC study of the pharmacokinetics of mezlocillin administered by 30-minute infusion and comparison with the direct intravenous route].

Mezlocillin pharmacokinetics were investigated in eighteen patients from a surgical service after a 30 minutes infusion with the purpose, on one hand, to compare this way of administration with a bolus intravenous infusion, and on the other hand to confirm or invalidate capacity-limited dose-dependent pharmacokinetics. Dosages were 2 g (n = 8) and 5 g (n = 10). Mezlocillin levels were measured by high performance liquid chromatography. Calculated data obtained with the 30 minutes infusion are different from those resulting from a bolus infusion. Peak levels, alpha and beta are lower ; T 1/2 beta, areas under the curve, and distribution volumes are higher. Most of the calculated data were not in agreement with a capacity-limited kinetic at the two studied dosages. The two regression-lines (2 g and 5 g) of mezlocillin body clearance versus creatinine clearance superimpose exactly. The 30 minutes infusion, and important hemodynamic variations between our 18 patients may partly explain the differences between our data and those published in the literature.