Eltrombopag — Drug Monograph

Brand names: Promacta, Revolade

Drug class: Supportive Care Agent

Mechanism of Action

Oral, small-molecule thrombopoietin receptor (TPO-R / c-Mpl) agonist that binds the transmembrane domain of the receptor (a site distinct from endogenous TPO), activating JAK2/STAT5 signaling to stimulate megakaryocyte proliferation and platelet production. In severe aplastic anemia it also stimulates multilineage hematopoietic stem/progenitor cell recovery. Eltrombopag chelates polyvalent cations (calcium, iron, magnesium, aluminum, zinc), which markedly reduces its absorption when taken with food or mineral-containing products.

FDA Indications

• Chronic immune thrombocytopenia (ITP) in adults and pediatric patients ≥1 year with insufficient response to corticosteroids, immunoglobulins, or splenectomy
• Severe aplastic anemia — first-line in combination with immunosuppressive therapy, and refractory disease
• Thrombocytopenia in patients with chronic hepatitis C to allow initiation and maintenance of interferon-based therapy

Common Side Effects

• Nausea
• Diarrhea
• Headache
• Fatigue
• Elevated ALT/AST
• Upper respiratory tract infection
• Cataract (with long-term use)

Clinical Pearl

Eltrombopag's cardinal counseling point is the empty-stomach, cation-free window: taking it with dairy, antacids, or an iron/calcium supplement can reduce absorption by up to 70%. East Asian patients require roughly half the usual starting dose due to higher plasma exposure. Beyond ITP, eltrombopag transformed the management of severe aplastic anemia by adding it to standard immunosuppression to boost multilineage hematopoietic recovery.

Related Therapies & Mechanisms

• Avatrombopag (Doptelet) — Supportive Care Agent · Supportive Care
• Defibrotide (Defitelio) — Supportive Care Agent · Supportive Care
• Dexrazoxane (Zinecard) — Supportive Care Agent · Supportive Care
• Fostamatinib (Tavalisse) — Supportive Care Agent · Supportive Care