Eltrombopag: TPO Receptor Agonist for Thrombocytopenia
Eltrombopag is an oral thrombopoietin receptor (TPO-R) agonist that stimulates platelet production in the bone marrow. The drug binds to the transmembrane domain of the TPO receptor (c-Mpl) and activates intracellular JAK/STAT and MAPK signaling pathways, promoting megakaryocyte proliferation and differentiation and thereby increasing platelet counts.
Unlike recombinant thrombopoietin analogs, eltrombopag is a synthetic, small-molecule oral compound, offering convenience of administration. On Unifarm, you can find generic versions of medications (such as Revolade, Promacta) containing this active ingredient.
Indications
- Chronic Immune Thrombocytopenia (ITP): Treatment of adults and children (≥1 year) with chronic immune thrombocytopenia who have had an insufficient response to corticosteroids, immunoglobulins, or splenectomy.
- Severe Aplastic Anemia (SAA): Treatment of adult patients with severe aplastic anemia who have had an insufficient response to immunosuppressive therapy, and as first-line treatment in combination with immunosuppressive therapy.
- Thrombocytopenia in Chronic Hepatitis C: Treatment of thrombocytopenia in patients with chronic hepatitis C virus infection to allow the initiation and maintenance of interferon-based antiviral therapy.
Dosage and administration
Available as film-coated tablets and powder for oral suspension (for pediatric use).
Standard Regimens:
- Chronic ITP (adults): Starting dose — 50 mg once daily. For patients of East Asian ancestry — 25 mg once daily. Dose adjusted to maintain platelet count ≥50×10⁹/L. Maximum dose — 75 mg daily.
- Chronic ITP (children 1–5 years): Starting dose — 25 mg once daily.
- Chronic ITP (children 6–17 years): Starting dose — 50 mg once daily.
- Severe Aplastic Anemia: Starting dose — 150 mg once daily. For patients of East Asian ancestry — 75 mg. Maximum dose — 150 mg daily.
- Hepatitis C: Starting dose — 25 mg once daily with subsequent adjustment.
Important: Take on an empty stomach (1 hour before or 2 hours after a meal). Allow at least 4 hours between eltrombopag and products containing calcium, aluminum, magnesium, iron, or zinc (antacids, dairy products, multivitamins) as they reduce absorption.
- Hypersensitivity to eltrombopag or any component of the product.
- Severe hepatic impairment (Child-Pugh C) for the ITP indication (caution and dose reduction for moderate impairment).
- Pregnancy and breastfeeding (potential risk to the fetus).
- Hereditary galactose intolerance, Lapp lactase deficiency (for tablets containing lactose).
Eltrombopag therapy requires regular monitoring of platelet counts, hepatic function, and peripheral blood smear. Common adverse reactions include:
- Hepatic: Elevated transaminases (ALT, AST), bilirubin — hepatotoxicity (monitoring every 2 weeks at treatment initiation).
- Thromboembolic events: Deep vein thrombosis, pulmonary embolism, myocardial infarction, stroke (especially when platelet counts exceed normal levels).
- Bone marrow: Reticulin fiber deposition (bone marrow fibrosis with prolonged use).
- Gastrointestinal: Nausea, diarrhea, vomiting.
- General: Headache, fatigue, musculoskeletal pain.
- Dermatologic: Rash, alopecia.
- Infections: Upper respiratory tract infections, nasopharyngitis.
- Ocular: Cataracts (observed in clinical trials; regular ophthalmologic monitoring recommended).
