The kinetics of cefuroxime in ascitic and pleural fluid

Adequate drug concentration at the infection site is a very important objective of antibiotic therapy. In this study we investigated the pharmacokinetics of the new methoximine, cefuroxime, in peritoneal and pleural fluids in 16 patients. After a 1-g dosage of cefuroxime, its concentration reaches a peak in ascitic fluid within 4-5 h. With a 2-g dose the peak level is reached in 2-3 h. After 5 h, cefuroxime concentration in ascites exceeds that in serum. Cefuroxime diffuses readily into the peritoneal space, where high concentrations (8-10 mcg/ml) are maintained for at least 6 h. Data on the kinetics in pleural fluid also seem to show high antibiotic diffusion rates, even if concentrations are never as high as those in blood at the same time following 1 g i.v. These favorable kinetic properties are probably due to low serum protein binding and to slow renal excretion.