Darbepoetin alfa

Indications

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

Adult Dose

Chronic Kidney Disease-Associated Anemia CKD not on dialysis Recommended starting dose: 0.45 mcg/kg IV/SC q4weeks Consider initiating ESA treatment only when the hemoglobin level is <10 g/dL If the hemoglobin level exceeds 10 g/dL, reduce or interrupt ESA dose and use the lowest dose sufficient to reduce the need for red blood cell transfusions CKD on dialysis Initiate ESA treatment when the hemoglobin level is <10 g/dL If the hemoglobin level approaches or exceeds 11 g/dL, reduce or interrupt the dose of ESA Recommended starting dose: 0.45 mcg/kg IV or SC qWeek or 0.75 mcg/kg q2weeks; the IV route is recommended for patietns on hemodialysis Intravenous route recommended for patients on hemodialysis Chemotherapy-Related Anemia with Nonmyeloid Malignancies 2.25 mcg/kg SC qWeek OR 500 mcg SC q3Weeks If Hgb increases <1 g/dL after 6 weeks, may increase dose no more than 4.5 mcg/kg Reduce dose by 40% if rapid increase in Hgb (eg, >1 g/dL in 2-week period) Discontinue if no response after 8 weeks

Child Dose

Chronic Kidney Disease-Associated Anemia Initiate treatment when the hemoglobin level is <10 g/dL If the hemoglobin level approaches or exceeds 12 g/dL, reduce or interrupt the dose Recommended starting dose for pediatric patients (<18 yr) is 0.45 mcg/kg SC or IV qWeek Patients not receiving dialysis may also be initiated at a dose of 0.75 mcg/kg q2Week Chemotherapy-related Anemia Safety and efficacy not established

Renal Dose

Chronic Kidney Disease-Associated Anemia CKD not on dialysis Recommended starting dose: 0.45 mcg/kg IV/SC q4weeks Consider initiating ESA treatment only when the hemoglobin level is <10 g/dL If the hemoglobin level exceeds 10 g/dL, reduce or interrupt ESA dose and use the lowest dose sufficient to reduce the need for red blood cell transfusions CKD on dialysis Initiate ESA treatment when the hemoglobin level is <10 g/dL If the hemoglobin level approaches or exceeds 11 g/dL, reduce or interrupt the dose of ESA Recommended starting dose: 0.45 mcg/kg IV or SC qWeek or 0.75 mcg/kg q2weeks; the IV route is recommended for patietns on hemodialysis Intravenous route recommended for patients on hemodialysis

Administration

Contra Indications

Hypersensitivity, uncontrolled hypertension.

Precautions

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. Lactation: not known if excreted in breast milk, use caution

Pregnancy-Lactation

Pregnancy Limited available data on pregnant women are insufficient to determine a drug-associated risk of major birth defects or miscarriage; in animal reproductive and developmental toxicity studies, drug increased early post-implantation loss at doses approximating clinical recommended starting doses; consider benefits and risks for the mother and possible risks to fetus when prescribing to a pregnant woman Lactation There is no information regarding presence of drug in human milk, effects on breastfed child, or on milk production; the developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for therapy and any potential adverse effects on breastfed child from drug or from underlying maternal condition

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% ) Frequency Not Defined Tumor progression, Venous thromboembolism, Immune hypersensitivity reaction (rare ), Injection site thrombosis

Mechanism of Action

Darbepoetin alfa is a biosynthetic form of erythropoietin. Recombinant human erythropoietin with sialic acid additions to enhance stability; stimulates erythropoiesis via division & differentation of progenitor cells in bone marrow to induce the release of reticulocytes from the bone marrow into the bloodstream to become erythrocytes.