New Drug of the day : Eltrombopag

New Pharmacological Drug Classes Introduced in 2008 

Eltrombopag is an orally available non-peptide thrombopoietin (TPO) receptor agonist licensed for the treatment of thrombocytopenia in patients with refractory chronic immune thrombocytopenic purpura. 

Eltrombopag is considered a second-generation thrombopoietin agent that does not lead to the development of TPO-neutralizing antibodies. Administration of eltrombopag produces a dose-dependent rise in platelet counts via JAK2 and STAT5 signaling pathways. 

The drug is a hydrazone compound and carries a black box warning regarding hepatotoxicity. As a class, TPO receptor agonists are thought to increase the risk for development of bone marrow fibrosis and may increase the risk for hematologic malignancies. Eltrombopaq may also promote the development of cataracts.