[Study of the bactericidal effect of cefpodoxime using an in vitro pharmacokinetic model]

Cefpodoxime is a new oral prodrug antibiotic. Following absorption from the proximal intestine, non-specific esterases hydrolyze this cleavable ester, releasing cefpodoxime, a new broad-spectrum third-generation cephalosporin with sustained plasma levels in humans. Cefpodoxime killing kinetics were studied using an in vitro model which simulates the pharmacokinetic profile obtained in healthy volunteers given a single oral dose of cefpodoxime proxetil providing 100, 200 or 400 mg active cefpodoxime. Cefpodoxime exhibited strong antibacterial activity against tested strains of Escherichia coli, Streptococcus pneumoniae and Staphylococcus aureus. These results suggest that use of two daily doses of 100 or 200 mg each are appropriate for the treatment of E. coli and S. pneumoniae infections in view of the pharmacokinetic properties of cefpodoxime. Less intensive therapy is probably adequate in uncomplicated community-acquired urinary tract infections. The bactericidal effect of cefpodoxime against S. aureus is prolonged due to a postantibiotic effect.