The stability of cefotaxime sodium at room and body temperatures in peritoneal dialysis solutions containing 1.5% or 4.25% dextrose was determined. Cefotaxime sodium 2 g was added to three 2-L bags of dialysis solution containing 1.5% dextrose, and cefotaxime sodium 500 mg was added to three 500-mL bags of dialysis solution containing 4.25% dextrose. The bags were stored at 25 or 37 degrees C Samples from bags stored at 25 degrees C were drawn aseptically at 0, 12, 24, 48, and 72 hours, and samples from bags stored at 37 degrees C were drawn at 0, 6, 12, and 24 hours. The pH of each sample was determined, and the cefotaxime concentration was measured by a stability-indicating high-performance liquid chromatographic method. At 37 degrees C the initial mean cefotaxime concentration declined to 97.9% at six hours, 89.1% at 12 hours, and 68.8% at 24 hours in the 1.5% dextrose solution; the mean percentages remaining in the solution containing 4.25% dextrose were 96.4%, 86.1%, and 71.0% at 6, 12, and 24 hours, respectively. At 25 degrees C the initial cefotaxime concentration declined to 92.4%, 84.4%, and 74.2% at 24, 48, and 72 hours, respectively, in 1.5% dextrose solution and to 92.0%, 84.3%, and 80.3% at 24, 48, and 72 hours, respectively, in 4.25% dextrose solution. In both solutions, cefotaxime concentration decreased by more than 10% at and after 12 hours at 37 degrees C and between 24 and 48 hours at 25 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)