Influence of cellulose triacetate hemodialyzers on vancomycin pharmacokinetics

This study was designed to evaluate the pharmacokinetics of vancomycin during hemodialysis with cellulose triacetate (CT) high-flux dialyzers and to assess the influence of membrane surface area on intradialytic clearance. In a randomized crossover fashion, the pharmacokinetics of vancomycin were evaluated during dialysis with the CT 110 and CT 190 membranes. Six hemodialysis patients received 1 g of vancomycin immediately after the completion of a dialysis session, and subsequently, blood samples were obtained over a 5-day study period. On Day 3 subjects were dialyzed with CT 110 or CT 190 membranes. The mean intradialytic clearance of vancomycin was 56.7 +/- 7.5 and 100.70 +/- 10.7 mL/min with the CT 110 and CT 190 membranes, respectively (P < 0.05). Significant rebound in vancomycin serum concentrations occurred after dialysis; this rebound appeared to be complete 3 h postdialysis. On the basis of postrebound concentrations, the apparent percent removal of vancomycin was 23.6 +/- 1.2 and 25.2 +/- 8.6% for CT 110 and CT 190 membranes, respectively (not significant). Vancomycin is significantly cleared during dialysis with cellulose triacetate membranes, and its clearance is dependent on membrane surface area. Although a small supplemental dose of vancomycin could be administered after dialysis to replace drug lost during dialysis, it may be more efficient to give a larger dose of vancomycin after several dialysis periods. The determination of vancomycin removal can be used to estimate vancomycin serum concentrations as well as dosage requirements. This in conjunction with serum concentration monitoring can be used to optimize vancomycin dosing.