A review of the pharmacokinetics of cefpodoxime proxetil

Cefpodoxime proxetil is an orally absorbed broad spectrum third generation cephalosporin antibacterial. It is a prodrug that is de-esterified in vivo to its active metabolite, cefpodoxime. After single- and multiple-dose (12-hourly) administration of cefpodoxime proxetil in the therapeutic dose range of 100 to 400mg of cefpodoxime equivalents, average peak plasma concentrations of cefpodoxime range from 1.0 to 4.5 mg/L and occur between 1.9 and 3.1 hours after administration. The half-life of cefpodoxime ranges from 1.9 to 2.8 hours. The absolute bio-availability of cefpodoxime proxetil tablets is 50%, and absorption is enhanced by concomitant administration of food. Raising gastric pH by pretreatment with antacids or H2-receptor antagonists results in reduced absorption. Binding of cefpodoxime to human plasma or serum protein is low (18 to 23%), suggesting that cefpodoxime should readily transfer across the capillary lining into tissues. Cefpodoxime undergoes minimal metabolism in humans. Drug not absorbed is degraded in the gastrointestinal tract and excreted in the faeces. As expected for a drug eliminated primarily by renal excretion, the disposition of cefpodoxime is altered in patients with impaired renal function; the half-life increases, while apparent plasma clearance and renal clearance decrease. The pharmacokinetics of cefpodoxime after oral administration of cefpodoxime proxetil are not affected by age.