Phosphate binders do not reduce bioavailability of oral cefuroxime-axetil in patients on peritoneal dialysis treatment.

Cefuroxime is a second-generation cephalosporin that can be used for the treatment of peritoneal dialysis-related peritonitis. Cefuroxime-axetil is an orally available pro-drug of cefuroxime. The effect of concomitant use of a phosphate binder on the bioavailability of cefuroxime-axetil was studied in 7 continuous ambulatory peritoneal dialysis (CAPD) patients who had not recently suffered from peritonitis. On two occasions, we measured cefuroxime levels in plasma, peritoneal effluent, and urine for 24 h after the ingestion of 1 g of cefuroxime-axetil: once together with a phosphate binder (+PB) and once without (-PB). Peak plasma concentrations (Cmax) were +PB: 22.7 mg/L (15.3-32.6) (median and range) and -PB: 23.2 mg/L (18.9-27.4). The area under the curve (AUC) of the plasma levels was +PB: 364 mg h/L (247-530) and -PB: 368 mg h/L (296-438). The plasma elimination half-life (t1/2) was +PB: 13.9 h (11.5-14.6) and -PB: 13.8 h (12.2-15.4). Cefuroxime concentrations in the peritoneal effluent from the first exchange were 1.9 mg/L (0.5-6.2) (+PB) and 3.4 mg/L (2.1-4.7) (-PB). In the peritoneal effluent from the second up to the last exchange, the cefuroxime levels were stable at +PB: 5.0 mg/L (2.0-8.8) and -PB: 5.3 mg/L (1.8-7.5). The total amount of cefuroxime excreted into peritoneal effluent and urine was +PB: 82 mg (30-124), -PB: 100 mg (36-129). So Cmax, AUC, t1/2 and the total amount of excreted cefuroxime were not different. Therefore, the bioavailability of cefuroxime-axetil is not reduced by the use of a phosphate binder.