Erythropoietin (EPO) is a glycoprotein hormone, which is the primary regulator of red blood cell formation in mammals. Recombinant human erythropoietin (r-HuEPO) is a purified glycoprotein, produced from mammalian cells into which the gene coding for human erythropoietin has been inserted.

Erythropoietin is indicated for the treatment of-

• Anemia associated with Chronic Renal Failure, including patients on dialysis and patients not on dialysis.
• Anemia in patients with non-myeloid malignancies where anemia is due to the effect of concomitantly administered chemotherapy.
• Anemic patients (hemoglobin >10 to <13 g/dL) are scheduled to undergo elective, noncardiac, nonvascular surgery to reduce the need for allogeneic blood transfusions.
• Anemia related to therapy with zidovudine in HIV-infected patients.

Treatment of anemia in chronic renal failure: Erythropoietin is administered to maintain hemoglobin concentration between 11 to 12 g/dl and hematocrit of 33-36 % in adults.

Starting dose:

• Adult: Usually 50 to 100 lU/kg three times in a week (TIW) by IV or Subcutaneous route.
• Pediatric: 50 lU/kg TIW by IV or Subcutaneous route.

Dose adjustment: Dose should be increased if hematocrit doses not increase by 5 to 6 points after 8 weeks therapy, and hematocrit is below suggested target range. Dose should be reduced when hematocrit approaches 36% or hematocrit increases >4 points in any 2-week period.

Maintenance dose: Maintenance dose must be individualized for each patient. In patients undergoing dialysis, the median maintenance dose is 75 lU/kg TIW, with a range from 12.5 to 525 lU/kg TIW as directed by the physician. In CRF patients not on dialysis, maintenance dose is 75 to 150 lU/kg/week.

Treatment of Anemia in Cancer Patients on Chemotherapy:

Starting dose:

• Adult: 150 lU/kg TIW by Subcutaneous route or 40,000 IU Subcutaneous route weekly.
• Pediatric: 25 to 300 lU/kg 3 to 7 times per week by Subcutaneous or IV route.

Dose adjustment: If the response is not satisfactory, the dose should be increased to 300 lU/kg TIW. If the hematocrit exceeds 40%, the dose should be withheld until the hematocrit falls to 36%.The dose should be reduced to 25% when treatment is resumed and titrated to maintain the desired hematocrit.

Surgery Patients: The recommended dose is 300 lU/kg/day subcutaneously for 10 days before surgery, on the day of surgery, and for 4 days after surgery. An alternate dose schedule is 600 lU/kg subcutaneously in once weekly dose (21, 14, and 7 days before surgery) plus a fourth dose on the day of surgery.

Zidovudine-treated HIV-infected Patients:

Starting dose

• Adult: 100 lU/kg as an IV or Subcutaneous injection TIW for 8 weeks.
• Pediatric: 50 to 400 lU/kg 2 to 3 times per week by Subcutaneous or IV route.

Dose adjustment: If the response is not satisfactory, the dose should be increased by 50-1001U/kg TIW. Response should be evaluated every 4 to 8 weeks thereafter and the dose adjusted accordingly by 50 to 100 lU/kg increments TIW.

Maintenance dose: The dose is titrated to maintain the hematocrit between 33-36%.

Administration

• Do not shake. It is not necessary to shake Erythropoietin. Prolonged vigorous shaking may denature any glycoprotein, rendering it biologically inactive.
• Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration.
• Administer as an intravenous injection over 1-2 minutes. In patients on dialysis, the injection should follow the dialysis procedure. Slow injection over 5 minutes may be beneficial to those who experience flu-like symptoms.
• Do not administer by intravenous infusion or in conjunction with other drug solutions.
• For the subcutaneous route, a maximum of 1 ml_ at one injection site should generally not be exceeded. In the case of larger volumes, more than one site should be chosen for the injection.

Erythropoietin is contraindicated in patients with:

• Uncontrolled hypertension
• Known hypersensitivity to mammalian cell-derived products
• A history of hypersensitivity to Erythropoietin or any component of the preparation.

General: Headache, dizziness, fever, malaise, arthralgia and occasionally hyperkalemia. Cardiovascular: Hypertension is the most common side effect, palpitations. Gastrointestinal: Nausea, vomiting, anorexia and diarrhea may occur occasionally. Allergic reactions.

Overdose Effects

Doses of up to 1500 lU/kg TIW for 3 to 4 weeks have been administered to adults without any direct toxic effects. If the suggested target range is exceeded, drug therapy may be temporarily withheld until the hemoglobin returns to the suggested target range. If polycythemia is of concern, phlebotomy may be indicated to decrease the hemoglobin.

Erythropoietin should be used with caution in those patients with controlled hypertension, ischaemic vascular disease, history of seizures, or suspected allergy to the product.

Iron evaluation: Prior to and during Erythropoietin therapy, the patient's iron stores, including transferrin saturation and serum ferritin, should be evaluated. Transferrin saturation should be at least 20%, and ferritin should be at least 100 ng/ml. Virtually all patients will require supplemental Iron to increase or maintain transferrin saturation to levels that will adequately support erythropoiesis.

Pregnancy & Lactation

Pregnancy Category C. Since there are no controlled studies of erythropoietin in pregnant women, and because animal reproduction studies are not always predictive of human responses, erythropoietin should be used during pregnancy only if clearly needed. It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when erythropoietin is administered to a nursing woman.