Abstract
We studied the effect of subcutaneous administration (SC) of recombinant human erythropoietin (rh-EPO) in hemodialysis (HD) patients. Fourteen HD patients, whose Hb level was already well maintained (8.98±0.81g/dl) with intravenous administration (IV) of rh-EPO, were selected for the study. In principle, SC doses of rh-EPO were half of the IV doses, once a week. Serum rh-EPO concentrations were measured almost every day for the first week. The effect was evaluated by the Hb ratio [Hb (on 4th or 8th week after SC)/Hb (before SC)×100%]. The effective group included patients with an Hb ratio≥98%, while in the non-effective group the Hb ratios≤97%. Eleven of 14 cases were in the effective group (78.6%). Among these 11 cases, weekly rh-EPO doses could be reduced, from 3, 545 IU/W IV to 2, 182 IU/W SC, on the 4th week. In the non-effective group, serum levels of total cholesterol and albumin were lower than those in the effective group. The rh-EPO concentration ratio [EPO (4W or 8W)/EPO (before)×100%] of the effective group was higher than that of the non-effective group (p<0.05, p<0.01). For the first 3 days after SC injection was initiated, serum rh-EPO concentrations were kept higher than they had been before SC injection (p<0.05). The average serum rh-EPO concentration was higher for the first 5 days. We speculate that, as with SC administration of rh-EPO, the serum rh-EPO concentration was elevated for a longer period than with IV administration, such that the SC dose could be reduced. The serum rh-EPO concentration ratio could serve as a parameter of the erythropoietic effect of rh-EPO.
