[Diffusion of cefotiam into ascitic fluid].

The large apparent volume of distribution of cefotiam (reported by Fourtillan et al. [4]), prompted an investigation of cefotiam diffusion into ascitic fluid. Eight patients with non-infected ascites were each given a single intravenous bolus of 2 gr cefotiam. Samples of blood and ascitic fluid were collected 0.5, 1, 2, 3, 4, 6 and 8 hours after the injection. Plasma and ascitic fluid concentrations of unchanged cefotiam were determined using HPLC. Peak concentration in ascitic fluid averaged 18 micrograms/ml and was reached at two hours. Concentrations were still high (approximately 13 micrograms/ml) at 8 hours, leading to further assays 12 and 24 hours after the injection in three subjects. Cefotiam concentrations achieved in ascitic fluid seem adequate for the treatment of infected ascites, given the antibiotic's MICs for the organisms most commonly involved.