Dosage recommendation of vancomycin during haemodialysis with highly permeable membranes.

The standard dosage of vancomycin in haemodialysis patients is usually 1 gram, once a week. The aim of our study was to investigate vancomycin clearance by two highly permeable membranes and to determine whether dosage adjustment is necessary in regular haemodialysis settings when using these type of dialyzers. 12 patients on regular haemodialysis and treated with vancomycin either prophylactically or therapeutically were prospectively randomised to either dialysis with a polyacrylonitril parallel membrane (AN-69) or a cellulose-acetate hollow fiber membrane. After administering vancomycin to the patient vancomycin plasma levels were measured at different intervals. The vancomycin clearance by the dialyzer was calculated from blood samples taken 1 hour after commencing dialysis. The data were used for pharmacokinetic computer simulation in order to develop a vancomycin dosage regimen for patients on regular haemodialysis with highly permeable membranes. The mean vancomycin dialysis clearance was 46 +/- 5 ml/min and did not differ between the two artificial kidneys. Dialysis clearance of vancomycin was independent of blood flow rate. Together with the dialyzer data a pharmacokinetic profile of each patient was calculated from the plasma samples. The average non-renal clearance was 3.3 ml/min/1.73 m2 while renal vancomycin clearance, as a fraction of creatinine clearance, was found to be 0.83 +/- 0.20. The computer calculations predicted that, irrespective of residual renal function, in most patients on regular haemodialysis and treated with these type of artificial kidneys, therapeutic and non-toxic vancomycin levels could be obtained by giving 1000 mg of vancomycin intravenously as a loading dosage and 500 mg during every subsequent dialysis.