Intraperitoneal recombinant human erythropoietin therapy: influence of the duration of continuous ambulatory peritoneal dialysis treatment and peritonitis.

This study was performed to investigate the factors that influence intraperitoneal absorption of recombinant human erythropoietin (rHuEPO) and to evaluate the differences of the pharmacokinetics of intraperitoneally administered rHuEPO before peritonitis and after recovery. First, the pharmacokinetics in different groups of continuous ambulatory peritoneal dialysis (CAPD) patients was studied. Thirty-six CAPD patients were enrolled and divided into four groups. Group 1 included 20 patients who were either just placed on CAPD therapy or had been on CAPD for < 1 year, but with a low frequency of peritonitis episodes. Group 1 was divided into four subgroups by body weight (20-30, 31-45, 46-55, and > 55 kg). Group 2, patients who had received CAPD treatment for more than 1 year, was further divided into group 2a and group 2b according to a low or a high frequency of peritonitis episodes, respectively. rHuEPO (100 U/kg) was administered as a single bolus of intravenous, subcutaneous, or intraperitoneal injection. Intraperitoneal rHuEPO was retained for 10 h. The results showed no significant differences between subcutaneous and intraperitoneal administration in group 1 patients. However, peak concentration, time to reach peak serum level, area under the curves, and bioavailability were substantially lower after intraperitoneal than after subcutaneous administration in group 2a and group 2b patients. There was no influence of body size on peak concentration and area under the curve in group 1 patients. Second, comparison of the pharmacokinetics of intraperitoneal administration before and after recovery from peritonitis in group 1 patients revealed that the serum levels of rHuEPO became lower after the occurrence of peritonitis.(ABSTRACT TRUNCATED AT 250 WORDS)