The kinetics of the aminothiazolyliminomethoxy cephalosporin, cefmenoxime, were determined after a 30 min intravenous infusion of 15 mg/kg body weight in 6 adult subjects undergoing continuous ambulatory peritoneal dialysis. Concentrations of cefmenoxime in serum, urine and dialysate were determined by high-pressure liquid chromatography. The mean peak serum concentration was 92.8 +/- 11.6 micrograms/ml and the harmonic mean for the elimination half-life was 5.46 h. The volume of distribution at steady-state was 14.60 +/- 3.01 l/kg. Total body clearance of the drug was 31 +/- 7.7 ml/min with 8 +/- 5% and 5.75 +/- 2.72% of the administered dose being eliminated by renal and peritoneal clearance, respectively. Peritoneal clearance for all exchanges (n = 24) was 1.93 +/- 68 ml/min. These data suggest that peritoneal losses of this drug are minimal and doses conventionally employed in advanced renal failure can be utilized in the management of systemic infections.