From the Guidelines
Darbepoietin should be used with caution in patients with chronic kidney disease or those undergoing chemotherapy, with a typical starting dose of 2.25 mg/kg administered once weekly by subcutaneous injection, and adjustments made based on hemoglobin response, as recommended by the most recent guidelines 1.
Key Considerations
- The target hemoglobin range for chronic kidney disease patients is typically 10-12 g/dL, and dose adjustments should occur no more frequently than every 4 weeks, increasing by 25% if hemoglobin rises less than 1 g/dL over 4 weeks, or decreasing by 25% if hemoglobin rises more than 1 g/dL in 2 weeks 2.
- Patients should be monitored regularly for blood pressure changes, as hypertension is a common side effect, and supplemented with iron, vitamin B12, and folate as needed to ensure optimal response to therapy 3.
- The use of darbepoietin may increase the risk of thromboembolism, and clinicians should carefully weigh the risks and benefits of treatment, particularly in patients with a history of thromboembolic events 4.
Dosing and Administration
- The initial dose of darbepoietin is 2.25 mg/kg administered once weekly by subcutaneous injection, with subsequent dose adjustments based on hemoglobin response 1.
- The dose may be increased to 4.5 mg/kg weekly if hemoglobin increases by less than 1 g/dL and remains below 10 g/dL after 6 weeks of therapy 2.
- The dose should be decreased by 40% when hemoglobin reaches a level needed to avoid transfusion or hemoglobin increases by more than 1 g/dL in 2 weeks 1.
Monitoring and Safety
- Patients should be monitored regularly for blood pressure changes, and for signs and symptoms of thromboembolism, such as chest pain, shortness of breath, or leg swelling 4.
- The use of darbepoietin may be associated with an increased risk of stroke, venous thromboembolic events, and malignancy, and clinicians should carefully weigh the risks and benefits of treatment 3.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Darbepoetin Alfa Overview
- Darbepoetin alfa is an amino acid substituted analog of human erythropoietin (EPO) that promotes erythrocyte survival, proliferation, and differentiation 5.
- It is characterized by delayed clearance and a more prolonged elimination half-life than recombinant human erythropoietin (rhEPO; epoetin alfa and beta), permitting an extended interval between doses 5.
Efficacy in Treating Anemia
- Darbepoetin alfa is effective in treating anemia associated with chronic kidney disease (CKD) in patients not on dialysis, with 95% of patients achieving a hemoglobin response 6.
- It is also effective in maintaining target hemoglobin levels in anemic patients with CKD, with a mean darbepoetin alfa dose at the time of response of 63.5 microg 6.
- In dialysis patients, darbepoetin alfa produced dose-related increases in hemoglobin over the first 4 weeks of treatment, with 60-80% of patients achieving a > or = 1 g/dl increase in hemoglobin 7.
Administration and Dosage
- Darbepoetin alfa can be administered once every other week, with a starting dose of 0.75 microg/kg 6.
- The optimal weekly starting dose is 0.45-0.75 microg/kg, and once weekly dosing is possible for both the subcutaneous and intravenous routes of administration 7.
- Darbepoetin alfa can be administered at 1- or 2-week intervals in the initial treatment of anemia associated with CKD, and at up to 4-week intervals to maintain hemoglobin levels established by prior erythropoietic treatment 5.
Safety and Tolerability
- Darbepoetin alfa is generally well tolerated, with adverse events consistent with those expected in patients with CKD 6.
- The adverse event profile is similar to that associated with rHuEpo therapy, and no antibodies to darbepoetin alfa were detected 7.
- Darbepoetin alfa reduces the need for blood transfusions in adults with CKD stage 3 to 5, but has little or no effect on mortality or quality of life 8.