Efficient monthly subcutaneous administration of darbepoetin in stable CAPD patients.
BACKGROUND
Although subcutaneous administration of recombinant human erythropoietin (rHuEPO) in continuous ambulatory peritoneal dialysis (CAPD) patients is a widely accepted recommendation, the lowest possible frequency of an efficient dosing regimen remains controversial. Darbepoetin alpha, a new erythropoiesis-stimulating protein with a threefold longer serum half-life compared with rHuEPO, has greater in vivo potency and can be administered less frequently to obtain the same biological response. This study assessed the efficacy of darbepoetin administered once monthly in the treatment of anemia in CAPD patients.


METHODS
In this single-center, prospective cohort study, 11 stable CAPD patients (5 males, 6 females; mean age 68.8 +/- 14.1 years; mean duration on peritoneal dialysis 31.6 +/- 13 months) maintained average hemoglobin and hematocrit levels of 12.09 +/- 1.29 g/dL and 37.29% +/- 3.58%, respectively, while receiving a mean weekly maintenance dose of epoetin alfa of 129 IU/kg. These same patients were assigned to receive the equivalent weekly darbepoetin dose once monthly for 24 consecutive weeks. Hematological response, iron status (transferrin saturation, serum ferritin levels), C-reactive protein (CRP), and the patients' biochemical profiles were evaluated monthly.


RESULTS
During the monthly administration of darbepoetin, mean serum levels of Hb and Hct were 12.17 +/- 1.28 g/dL and 37.1% +/- 1.19% respectively. No statistically significant difference was apparent between the previous and monthly dosing values (12.09 +/- 1.29 vs 12.17 +/- 1.28 g/dL, p = 0.769, and 37.29% +/- 3.58% vs 37.1% +/- 1.19%, p = 0.752). Transferrin saturation levels as well as serum ferritin levels also remained unchanged (30.4% +/- 8.6% vs 30.1% +/- 9.4%, NS, and 556 +/- 212 vs 621 +/- 234 ng/mL, respectively, NS).


CONCLUSIONS
These results indicate that darbepoetin alfa can be effectively given subcutaneously at monthly intervals for the treatment of anemia in stable CAPD patients. However, more studies are needed to validate the long-term efficacy of this monthly subcutaneous administration.
Theodoridis
Marios
M
Department of Nephrology, Medical School, Democritus University of Thrace, Alexandroupolis, Greece. cymarth@otenet.gr
Passadakis
Ploumis
P
Kriki
Pelagia
P
Panagoutsos
Stelios
S
Yannatos
Evangelos
E
Kantartzi
Konstantia
K
Sivridis
Dimitris
D
Vargemezis
Vasilis
V
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000740:Anemia / Q000097:blood / Q000188:drug therapy* / Q000209:etiology; D000068256:Darbepoetin alfa; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D004921:Erythropoietin / Q000008:administration & dosage / Q000031:analogs & derivatives*; D005260:Female; D005500:Follow-Up Studies; D006400:Hematocrit; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D007279:Injections, Subcutaneous; D007501:Iron / Q000097:blood; D007676:Kidney Failure, Chronic / Q000150:complications / Q000628:therapy; D008297:Male; D008875:Middle Aged; D010531:Peritoneal Dialysis, Continuous Ambulatory; D011446:Prospective Studies; D016896:Treatment Outcome
D006454:Hemoglobins; D004921:Erythropoietin; D000068256:Darbepoetin alfa; D007501:Iron