We have studied the pharmacokinetics of teicoplanin, a new glycopeptide antibiotic active against Gram-positive aerobic and anaerobic bacteria, in five patients with end-stage renal disease on continuous ambulatory peritoneal dialysis (CAPD). Although teicoplanin was eliminated in the peritoneal fluid, relatively little was recovered (6.8 +/- 1.2% of the given dose). The following values were obtained: elimination half-time 102-347 h; total body clearance 4.16-7.38 ml X h-1 X kg-1, peritoneal clearance 0.31-0.37 ml X h-1 X kg-1. Because the elimination of teicoplanin is about four times less in patients undergoing CAPD compared with subjects with normal renal function, the dose of teicoplanin should be reduced appropriately in such cases.