THE PHARMACOKINETICS OF RECOMBINANT-HUMAN-ERYTHROPOIETIN AFTER INTRAVENOUS AND SUBCUTANEOUS ADMINISTRATION TO HEALTHY-SUBJECTS

1. The pharmacokinetics of recombinant erythropoietin, r‐Epo, were evaluated after intravenous and subcutaneous administration of 50 u kg‐ 1 to six healthy male volunteers. 2. The calculated mean values (+/− s.d.) for volume of distribution at steady state and clearance after an i.v. dose were 76 (+/− 33) ml kg‐1 and 12 (+/− 3) ml h‐1 kg‐1, respectively. 3. Serum concentrations of r‐Epo peaked at 13 (+/− 6) h after the s.c. dose and the bioavailability over 72 h was 36 (+/− 23)%. The mean residence time and half‐life of erythropoietin were 6.2 (+/− 1.0) and 4.5 (+/− 0.9) h respectively after i.v. and 46 (+/− 18) and 25 (+/− 12) h after s.c. administration. 4. The results demonstrate the possibility of changing the profile of the concentration‐time curve by changing the mode of administration of r‐Epo, with implications for the time‐course of clinical response. 1990 The British Pharmacological Society