Antibacterial activity of cefpodoxime proxetil in a pharmacokinetic in-vitro model

The antibacterial activity of cefpodoxime proxetil was studied in an in-vitro model simulating doses of 100, 200 and 400 mg. Strains of Klebsiella spp. Proteus mirabilis, Escherichia coli, Streptococcus pyogenes, and Haemophilus influenzae were effectively reduced by a dose of 200 mg. While for Esch. coli no dose-activity relationship was observed--the maximal effect was achieved with a simulated dose of 100 mg--Staphylococcus aureus could be reduced effectively only by a simulated dose of 400 mg. The lower doses showed stepwise lower activities. Apart from broad spectrum beta-lactamases like SHV 2 or TEM 5 the presence of plasmid coded beta-lactamases in Esch. coli and H. influenzae did not affect the antibacterial activity of cefpodoxime proxetil. The results show that cefpodoxime was more active against Gram-negative bacteria than amoxycillin, and comparable activity to intramuscular cefotiam in the in-vitro model.