Home Drug Guide Darbepoetin Alfa

Drug Guide

Generic Name

Darbepoetin Alfa

Brand Names Aranesp

Classification

Therapeutic: Erythropoiesis-stimulating agent (ESA)

Pharmacological: Synthetic erythropoietin derivative

FDA Approved Indications

Anemia associated with chronic kidney disease (CKD) in patients on dialysis
Anemia due to CKD in non-dialysis patients
Anemia caused by chemotherapy in cancer patients

Mechanism of Action

Darbepoetin Alfa stimulates erythropoiesis by binding to erythropoietin receptors on erythroid progenitor cells in the bone marrow, promoting their proliferation and differentiation.

Dosage and Administration

Adult: Dose varies based on hemoglobin levels, usually 0.45 mcg/kg once weekly or 0.75 mcg/kg every 2 weeks; adjustments are made based on response.

Pediatric: Approved for certain pediatric CKD patients; dosing is similar but adjusted for body weight and response.

Geriatric: Use with caution; dosing adjustments may be needed due to increased sensitivity in older adults.

Renal Impairment: Adjust dose based on hemoglobin response and risk of cardiovascular events.

Hepatic Impairment: No specific dose adjustment required.

Pharmacokinetics

Absorption: Delayed, subcutaneous or intravenous, with peak levels in 24 hours.

Distribution: Widely distributed in body tissues.

Metabolism: Metabolized in the reticuloendothelial system, with minimal hepatic involvement.

Excretion: Excreted primarily via cellular catabolism, not by renal pathway.

Half Life: Approximately 48.8 hours after subcutaneous administration.

Contraindications

Uncontrolled hypertension
Hypersensitivity to darbepoetin alfa or any excipients

Precautions

Risk of cardiovascular events, stroke, hypertension, pure red cell aplasia, iron deficiency, allergy

Adverse Reactions - Common

Hypertension (Common)
Arthralgia (Common)
Headache (Common)

Adverse Reactions - Serious

Pure red cell aplasia (PRCA) (Rare)
Thromboembolic events including stroke, myocardial infarction (Serious / Rare)
Seizures (Rare)

Drug-Drug Interactions

Androgens, which can increase erythropoietic activity

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor hemoglobin, hematocrit, blood pressure, and iron levels.

Diagnoses:

Risk for hypertension
Impaired tissue perfusion

Implementation: Administer as prescribed, monitor response, and adjust dose accordingly.

Evaluation: Assess hemoglobin levels regularly; aim for target range without exceeding it.

Patient/Family Teaching

Report signs of hypertension, seizures, or allergic reactions.
Maintain regular blood tests as scheduled.
Follow instructions for administration and storage.

Special Considerations

Black Box Warnings:

Increased risk of death, myocardial infarction, stroke, venous thromboembolism, or tumor progression when used excessively or inappropriately.
Use the lowest effective dose to reduce the need for blood transfusions.

Genetic Factors: None specified.

Lab Test Interference: May interfere with some blood tests, including hemoglobin and hematocrit measurement.

Overdose Management

Signs/Symptoms: Hypertension, excessively high hemoglobin or hematocrit levels.

Treatment: Discontinue drug, provide supportive care, and manage blood pressure; in severe cases, hospitalization may be necessary.

Storage and Handling

Storage: Store in a refrigerator (2°C to 8°C); do not freeze.

Stability: Stable through expiration date when stored properly.