Darbepoetin alfa

Indications

Darbepoetin alfa is used for: Anaemia of chronic renal failure, Anaemia in chemotherapy patients

Adult Dose

Parenteral Anaemia of chronic renal failure Adult: Initially, 0.45 mcg/kg SC/IV once weekly. Alternatively, 0.75 mcg/kg every 2 weeks or 1.5 mcg/kg once monthly via SC inj in patients not on dialysis. Dose may be increased or decreased by 25% once every 4 weeks, according to Hb level. Maintenace dose: 0.45 mcg/kg SC/IV once weekly or once every 2 weeks. Titrate dose to maintain target Hb level. Subcutaneous Anaemia in chemotherapy patients Adult: Initially, 500 mcg once every 3 weeks. Alternatively, 2.25 mcg/kg once weekly. Dose reduction up to 50%, dosing interruption, or discontinuation may be required according to Hb level (refer to detailed product guideline). Discontinue therapy approx 4 weeks after the end of chemotherapy.

Child Dose

Parenteral Anaemia of chronic renal failure Child: Initially, 0.45 mcg/kg SC/IV once weekly. Alternatively, 0.75 mcg/kg every 2 weeks or 1.5 mcg/kg once monthly via SC inj in patients not on dialysis. Dose may be increased or decreased by 25% once every 4 weeks, according to Hb level. Maintenace dose: 0.45 mcg/kg SC/IV once weekly or once every 2 weeks. Titrate dose to maintain target Hb level.

Renal Dose

Administration

IV Administration May be administered SC or IV bolus Do not shake; vigorous shaking may denature darbepoetin alfa, rendering it biologically inactive Do not dilute or administer in conjunction with other drug solutions Discard any unused portion of the vial Do not pool unused portions Discontinue immediately if signs/symptoms of anaphylaxis occur

Contra Indications

Hypersensitivity, uncontrolled hypertension.

Precautions

Pregnancy and lactation, children. Hypertension; history of seizures; hepatic impairment; sickle cell anaemia; sudden stabing migraine-like pain (warning sign of hypotensive crisis); exclude other causes of anaemia; ischaemic vascular disease; thrombocytosis; epilepsy; malignant disease; increase in heparin dose may be needed; increased risk of thrombosis when used for anaemia before orthopedic surgery; CV disease including recent MI/cerebrovascular accident. Monitor haemoglobin, BP and electrolytes; platelet count for 1st 8 wk.

Pregnancy-Lactation

Interactions

Antagonism of hypotensive effect and increased risk of hyperkalemia with ACE inhibitors and angiotensin II receptor antagonists. Ethanol.

Adverse Effects

Side effects of Darbepoetin alfa : >10% Cancer patients Fatigue (33%) Diarrhea (22%) Edema (21%) Fever (19%) Dizziness (14%) Arthralgia (13%) Headache (12%) Death (10%) Chronic renal failure patients Infectious disease (24%) Hyper/Hypotension (20%) Spasm (17%) Upper respiratory infection, Headache (15%) Diarrhea, Vomiting (14%) Nausea (11%) Peripheral edema, Dyspnea (10%) Abdominal pain (10%) 1-10% Cancer patients Myalgia (8%) Hypertension (3.7%) Pneumonia (3%) Dyspnea (2%) Vomiting (2%) Pulmonary embolism (1.3%) Chronic renal failure patients Arthralgia, Cough, Fatigue (9%) Limb pain (8%) Dizziness, Fever (7%) Death (6%) Edema (6%) Anemia, DVT, red cell aplasia (5.6%) Cardiac arrest, Cardiac dysrhythmia, Congestive heart failure (5%) Myocardial infarction, CVA (2%) <1% Cancer patients Hypertensive encephalopathy (0.6%) Seizure (0.6%) Chronic renal failure patients Hypertensive encephalopathy (<1%) Seizure (<1%) Transient ischemic attack (<1% )

Mechanism of Action

Darbepoetin alfa is a biosynthetic form of erythropoietin. It stimulates the division and differentiation of erythroid progenitor cells; reticulocytes are released from the bone marrow and matures into erythrocytes thereby regulating erythropoiesis.