Testing a single monthly dose of darbepoetin alpha to maintain hemoglobin levels in continuous ambulatory peritoneal dialysis patients.

The newly developed erythropoiesis agent darbepoetin alpha (DA) allows for once-monthly dosing in the treatment of anemia in patients on dialysis. This dosing schedule has prompted some studies to examine the efficacy of DA in patients on continuous ambulatory peritoneal dialysis (CAPD). In the present study, we assessed whether intravenous (IV) administration of DA once monthly is effective for maintaining hemoglobin levels near 10.5 g/dL in patients on CAPD. This single-center prospective cohort study included 52 clinically stable patients (25 men, 27 women; mean age: 59 +/- 10 years). All patients had been on a stable weekly or twice monthly regimen of recombinant human erythropoietin (rHuEPO) before initiation of the study. To determine the monthly dose of DA, the previously used mean weekly dose of rHuEPO was divided by 200 to determine the equivalent weekly dose of DA in micrograms; that number was then multiplied by 4 to generate the monthly dose requirement. For example, if 3000 IUrHuEPO was being administered weekly, then the monthly dose of DA was calculated to be 60 microg (3000/200 x 4). All patients received a monthly dose of DA the first month, and hemoglobin and other routine laboratory tests were performed monthly for 24 consecutive weeks. In 26 patients, the calculated monthly DA dose remained stable. The monthly dose was increased by 25% in 22 patients and by 50% in 4 patients. With regard to iron stores and iron availability for erythropoiesis, no significant differences were observed in the patients on various doses of DA. Nonsignificant differences in weekly creatinine clearance as determined using the PD Adequest software (Baxter Healthcare, Tokyo, Japan) were observed between the groups. No clinically meaningful differences in other laboratory values between the groups were observed. Once-monthly administration of DA is not always sufficient to maintain hemoglobin levels in patients on CAPD when adequate dialysis therapy is not achieved.