How Do Erythropoiesis-Stimulating Agents Work?

Erythropoiesis-stimulating agents (ESAs) are medications used to treat anemia caused by chronic kidney disease (CKD). These drugs stimulate the production of red blood cells (RBCs) in the bone marrow by continuously activating the erythropoietin receptors, resulting in increased RBCs in the blood; therefore, anemia is treated without the need for blood transfusions.

Erythropoietin is a hormone produced by interstitial cells within the kidney. Whenever the oxygen levels decrease in the body, this hormone stimulates the precursor cells in bone marrow to produce RBCs. The production of erythropoietin decreases in patients with CKD which causes anemia. However, there are other factors that may cause anemia.

• Chemotherapy given for any type of cancer may decrease all types of blood cells, leading to anemia, thrombocytopenia (low platelets), and leukopenia (low white blood cells).
• Need for allogenic RBCs transfusion during or following major surgery or excessive blood loss following trauma
• Treatment of HIV or AIDS

ESAs are to be taken on the advice of health care professionals; misuse of these drugs may cause cardiovascular diseases.

ESAs are given as intravenous or subcutaneous injections for the treatment of anemia caused by the following:

• Chronic kidney disease 
• Chemotherapy 
• HIV treatment with zidovudine 
• Major surgery

Side effects of ESAs may include:

• Nausea and vomiting
• Fever
• Injection site reactions
• Hypertension
• Cough
• Headache
• Muscle and joint pains
• Diarrhea
• Dizziness
• Fatigue
• Irritability
• Vascular occlusion
• Chest pain
• Upper respiratory tract infection
• Anaphylaxis (life-threatening allergic reactions)

The information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these drugs do not cause any harm when you take them along with other medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.

Generic and brand names of ESAs include:

• Epoetin alfa
• Epoetin alfa-epbx
• Epogen
• Eprex
• Erythropoietin
• Procrit
• Retacrit