Prediction of serum vancomycin concentrations following intraperitoneal loading doses in continuous ambulatory...

The pharmacokinetics of vancomycin were studied in continuous ambulatory peritoneal dialysis patients with peritonitis. Six patients received an intraperitoneal loading dose of 15 mg/kg and 4 received an intraperitoneal dose of 25 mg/L. The ability of 2 methods to predict serum concentrations during the loading dose exchange was determined. The mean serum concentration after the exchange was 17.8 +/- 2.2 mg/L in patients receiving the loading dose. The mean dialysis clearance in all patients was 0.94 +/- 0.34 L/h. 66.6 +/- 13.4% of a dose was absorbed into the circulation in 4 h. The volume of distribution was 0.61 +/- 0.46 L/kg, and the half-life for equilibration of vancomycin into the circulation from dialysate was 2.76 +/- 0.94 h. Two methods of predicting serum vancomycin concentrations were tested, with 1 method predicting values significantly different from measured concentrations while the other did not. Serum vancomycin concentrations can be accurately predicted during a loading dose exchange.