#aranesp

Common Brand Names: Aranesp

Therapeutic Class: Colony stimulating factor, growth factor.

Common Injectable Dosage Forms:

Polysorbate Solution: 25 mcg/mL, 40 mcg/mL, 60 mcg/mL, 100 mcg/mL, 200 mcg/mL

Albumin Solution: 25 mcg/mL, 40 mcg/mL, 60 mcg/mL, 100 mcg/mL, 150 mcg/0.75 mL, 200 mcg/mL, 300 mcg/mL, 500 mcg/mL

Dosage Ranges:

For the treatment of anemia associated with chronic renal failure: The recommended starting dose is 0.45 mcg/mL, administered as a single IV or SC injection once a week. Because of individual variability, doses should be titrated to not exceed target hemoglobin concentration of 12 g/dL. Maintenance doses can be less than the starting dose and some patients have been treated successfully with every other week dosing. Dosage increases should not occur more frequently than every 4 weeks. If hemoglobin increases by more than 1.0 g/dL in a 2-week period, decrease the dose by 25%.

For the treatment of anemia in patients with non-myeloid malignancies where anemia is due to the effect of concomitantly administered chemotherapy: The recommended starting dose is 2.25 mcg/kg administered as a weekly SC injection. If hemoglobin increases by more than 1.0 g/dL in a 2-week period or if the hemoglobin concentration exceeds 12 g/dL, the dose should be reduced by 25%.

Administration and Stability: Aranesp should be stored under refrigeration at 2°-8°C (36°-46°F). Do not freeze or shake. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration. Do not use any vials exhibiting particulate matter or discoloration. Do not dilute or administer with any other drug solutions. Discard any unused portion due to the lack of preservatives.

Pharmacology/Pharmacokinetics: Darbepoetin alfa is an erythropoiesis stimulating protein made in Chinese hamster ovary cells by recombinant DNA technology. It differs from recombinant human erythropoietin in that it contains 5 N-linked oligosaccharide chains instead of 3 chains. Erythropoietin is made in the kidneys and is released into the bloodstream in response to hypoxia. It then stimulates red cell production after interacting with progenitor stem cells. Darbepoetin alfa stimulates erythropoiesis by the same mechanism. Anemia in patients with chronic renal failure is usually caused by a decrease in endogenous erythropoietin production. Subcutaneous administration results in a slow absorption and a half-life of 49 hours. Intravenous administration results in mean terminal half-life of 21 hours.

Drug and Lab Interactions: No known drug interactions exist.

Contraindications/Precautions: Contraindicated in patients with uncontrolled hypertension and in patients with known hypersensitivity to the active ingredient or any of the excipients. High hemoglobin and/or high rates of rise of hemoglobin increase the risk of cardiovascular events, including death. The hemoglobin level should be managed carefully to avoid exceeding a target dose of 12 g/dL or rise of more than 1.0 g/dL in a 2-week period. Blood pressure may rise during treatment and special care should be taken to closely monitor and control blood pressure. Use with caution in patients with chronic renal failure. Pregnancy Category C.

Monitoring Parameters: Hemoglobin, iron stores, blood pressure.

Adverse Effects: The most frequent adverse effects include infection, hypertension, hypotension, myalgia, headache, nausea/vomiting, and diarrhea. The most frequent serious adverse effects include thrombotic events, congestive heart failure, sepsis, and cardiac arrhythmias. There is a theoretical risk for transmission of viral diseases with the use of the albumin (human) solution.