The plasma pharmacokinetics of high dose (1 g) imipenem coadministered with 1 g cilastatin in six normal volunteers.

The plasma pharmacokinetics of imipenem, a beta-lactam antibiotic of the new class of carbapenems, was evaluated by administering 1 g imipenem plus 1 g of the dehydropeptidase inhibitor cilastatin to six healthy male volunteers over 30 min. Subsequently intensive plasma sampling was done for 5.5 h. The volume of distribution of the central compartment was 0.16 +/- 0.04 1/kg; the volume of distribution (area) was 0.28 +/- 0.07 1/kg; the volume of distribution (steady state) was 0.23 +/- 0.03 1/kg. The mean plasma clearance was 10.1 +/- 1.0 1/h/1.73 m2. Model-independent analysis showed excellent agreement with these values. The terminal excretion half-life was short (1.3 +/- 0.4 h). For approximately 6 h after administration, the observed plasma levels were above those required to inhibit most nosocomial pathogens in vitro.