Markedly increased clearance of vancomycin during hemodialysis using polysulfone dialyzers

Clearance of a drug during hemodialysis is affected by drug specific, membrane specific and dialysis specific factors [1, 2]. Drug specific properties determining dialysability include its volume of distribution (Vd), protein binding and molecular weight. Dialyzer membrane specific factors include surface area, permeability and adherence of the drug to the membrane. Finally, blood flow and dialysate flow also influence drug clearance.Vancomycin is commonly used in patients for the treatment of gram + infections. More than 90% of the drug is excreted by the kidneys; however, in the presence of renal failure significant dosage adjustments are required. The half life of vancomycin is quite prolonged in ESRD (200 hours) as compared to those with normal renal function (6 to 8 hours) [3–9]. Typically, vancomycin is not appreciably removed by the cuprophane or cellulose acetate membranes used in conventional hemodialysis. However, with the introduction of the newer, more permeable membranes, such as the polysulfone dialyzers, the pharmacokinetics of vancomycin removal during hemodialysis may be increased since vancomycin has a small Vd (0.47 to 0.84 liter/kg), minimal protein binding [3, 5, 9] and a relatively low molecular weight (1500 daltons) [3]. The purpose of the present study was therefore, to determine whether polysulfone membranes increased the clearance of vancomycin