Once Weekly Intraperitoneal Therapy for Gram-Positive Peritonitis

The pharmacokinetics and clinical outcome following a 30 mg/kg/2 L intraperitoneal (IP) dose of vancomycin, which was administered once a week for 3 weeks, was studied in ten continuous ambulatory peritoneal dialysis patients with peritonitis. Vancomycin was 91% absorbed following the first dose and rapidly achieved therapeutic serum concentrations, 19 ± 8 mcg/mL at 1 hour and a peak of 37 ± 8 mcg/mL at 6 hours. Vancomycin was eliminated slowly with a mean total clearance of 7 ± 3 mL/min/70 kg and a distribution volume of 1.2 ± 0.3 L/kg. The resultant mean serum t_1/2 over the first week was 184 hours and the mean serum concentration at 168 hours was 10 ± 4 mcg/mL. Based on the positive clinical outcome (100% cure) among patients with uncomplicated gram-positive peritonitis, the potential use of this alternative vancomycin dosing regimen is proposed.