Penetration of Metronidazole into Continuous Ambulatory Peritoneal Dialysate

Seven patients receiving continuous ambulatory peritoneal dialysis were given 400 mg of oral metronidazole every eight hours for three days. Plasma, dialysate and urine were collected during the final 24 hours and assayed for metronidazole and its two principal oxidative metabolites by a specific, high-performance, liquid-chromatographic method. Concentrations of metronidazole in plasma and dialysate were similar and were greater than the minimum inhibitory concentration for susceptible anaerobes. There was evidence of retention of both oxidative metabolites. This study shows that oral metronidazole in standard dosages achieves bactericidal concentrations in peritoneal fluid and should be effective in the treatment of peritonitis due to anaerobic bacteria.