Pharmacokinetics of recombinant human erythropoietin in dialysis patients after single and multiple subcutaneous administrations.

The pharmacokinetics of recombinant human erythropoietin (rhEPO) were evaluated after single intravenous and single subcutaneous administration of 40 U/kg to 8 patients with dialysis treatment. All patients suffered from renal anemia with a hematocrit less than or equal to 24% and were treated with 40 U/kg rhEPO subcutaneously, three times a week for 6 weeks. At the end of the treatment period, kinetics of rhEPO were repeated. After the initial subcutaneous rhEPO dose, the following results were obtained: maximum plasma concentration 39.5 (26.7-56.9) U/l, area under the curve (AUC) 1,122 (582-3,220) U.h.1-1 and terminal half-life 13.2 (2.6-53.1) h. The corresponding data after multiple rhEPO doses were: maximum rhEPO plasma concentration 26.3 (9.4-49.1) U/l, AUC 724 (407-1,464) U.h.1-1 and terminal half-life 14.2 (3.5-24.4) h. There were no statistical significant differences between the two investigations. From the present study, it can be concluded that after a treatment period of 6 weeks with multiple subcutaneous rhEPO doses, rhEPO absorption as well as rhEPO elimination are unchanged.