Pharmacokinetics of epoetin (recombinant human erythropoietin) after long term therapy in patients undergoing haemodialysis and haemofiltration.

After long term therapy with epoetin (recombinant human erythropoietin) 17 patients with end-stage renal disease (ESRD) were studied in 3 groups to assess pharmacokinetics during the intertreatment interval and during haemofiltration and dialysis treatment. Epoetin was measured by radioimmunoassay. After an intravenous bolus of epoetin 150 U/kg bodyweight, the half-life was 7.7h, steady-state volume of distribution was 0.066 L/kg and total plasma clearance was 5.4 ml/min. The mean steady-state serum concentration during multiple-dose administration was 656 U/L. The drug was not eliminated by haemofiltration or dialysis. Long term treatment of ESRD patients with epoetin does not significantly alter the pharmacokinetic profile of the drug. Epoetin dosage adjustment or substitution after haemofiltration and dialysis is not necessary.