darbepoetin alfa

darbepoetin alfa,

a hematopoietic agent used to treat anemia associated with chronic renal failure or anemia in nonmyeloid malignancies.

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darbepoetin alfa

Aranesp

Pharmacologic class: Recombinant human erythropoietin

Therapeutic class: Hematopoietic

Pregnancy risk category C

FDA Boxed Warning

• Use lowest dose that will increase hemoglobin gradually to lowest level sufficient to avoid need for red blood cell (RBC) transfusion.
• Drug increases risk of death and serious cardiovascular events when given to target hemoglobin level above 12 g/dL.
• In patients receiving radiation therapy for advanced head and neck cancer, drug shortens time to tumor progression when given to target hemoglobin level above 12 g/dL.
• In patients receiving chemotherapy for metastatic breast cancer, drug shortens overall survival and increases deaths from disease progression at 4 months when given to target hemoglobin level above 12 g/dL.
• In patients with active cancer who are receiving neither chemotherapy nor radiation therapy, drug increases risk of death when given to target hemoglobin level of 12 g/dL. Drug isn't indicated for these patients.
• Patients who received epoetin alfa preoperatively to reduce need for allogeneic RBC transfusion but weren't receiving prophylactic anticoagulation had higher incidence of deep vein thrombosis. Dalteparin isn't approved to reduce need for RBC transfusion.

Action

Stimulates erythropoiesis in bone marrow, increasing red blood cell production

Availability

Albumin solution for injection: 25 mcg/ml, 40 mcg/ml, 60 mcg/ml, 100 mcg/ml, 150 mcg/ml, 200 mcg/ml, 300 mcg/ml, 500 mcg/ml

Polysorbate solution for injection: 25 mcg/ml, 40 mcg/ml, 60 mcg/ml, 100 mcg/ml, 150 mcg/ml, 200 mcg/ml, 300 mcg/ml

⊘Indications and dosages

➣ Anemia caused by chronic renal failure

Adults: Initially, 0.45 mcg/kg I.V. or subcutaneously as a single dose once weekly. Titrate dosage to maintain target hemoglobin concentration no higher than 12 g/dl. Adjust dosage no more often than once monthly.

➣ Chemotherapy-induced anemia in patients with nonmyeloid malignancies

Adults: 2.25 mcg/kg I.V. or subcutaneously q week. Titrate dosage to maintain target hemoglobin concentration no higher than 12 g/dl.

Contraindications

• Hypersensitivity to drug
• Uncontrolled hypertension

Precautions

Use cautiously in:
• anemia; thalassemia; porphyria; seizures; underlying hematologic disease, including hemolytic and sickle cell anemia
• pregnant or breastfeeding patients
• children.

Administration

• Give by subcutaneous or I.V. injection only.
• Don't dilute or give with other drug solutions.
☞ Don't shake. Vigorous shaking may denature drug, making it biologically inactive.
• Give single I.V. dose over 1 minute.
• Discard unused portion. (Drug contains no preservative.)

Route	Onset	Peak	Duration
I.V., subcut.	2-6 wk	Unknown	Unknown

Adverse reactions

CNS: dizziness, headache, fatigue, weakness, seizures, transient ischemic attack, cerebrovascular accident

CV: hypertension, hypotension, chest pain, peripheral edema, arrhythmias, heart failure, cardiac arrest, myocardial infarction, vascular access thrombosis

GI: nausea, vomiting, diarrhea, constipation, abdominal pain

Metabolic: fluid overload

Musculoskeletal: myalgia; joint, back, and limb pain

Respiratory: cough, upper respiratory tract infection, dyspnea, bronchitis

Skin: pruritus

Other: fever, flulike symptoms, infection, pain at injection site

Interactions

None significant

Patient monitoring

• Assess hemoglobin concentration before starting therapy and then weekly during therapy.
• Observe closely for serious CNS and cardiovascular adverse reactions.
• Know that supplemental iron is recommended for patients with serum ferritin level below 100 mcg/ml or serum transferrin saturation below 20%.

Patient teaching

• Tell patient to report chest pain or other pain, muscle tremors, weakness, and cough or other respiratory symptoms.
• If patient will self-administer drug, tell him to follow exact directions for injection and needle disposal.
• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration and alertness.
• Advise patient to minimize GI upset by eating small, frequent servings of healthy food and drinking plenty of fluids.
• Tell patient he'll undergo frequent blood testing during therapy to help determine correct dosage.
• As appropriate, review all other significant and life-threatening adverse reactions.