Eltrombopag

Eltrombopag is a hydrazine in which each nitrogen atom is substituted, one by a 3'-carboxy-2-hydroxy[1,1'-biphenyl]-3-yl group and the other by a 1-(3,4-dimethylphenyl)-3-methyl-5-oxo-1,5-dihydro-4H-pyrazol-4-ylidene group. A small molecule agonist of the c-mpl (TpoR) receptor (the physiological target of the hormone thrombopoietin), it has been developed as a medication for conditions that lead to thrombocytopenia (abnormally low platelet counts). It has a role as a thrombopoietin receptor agonist and a xenobiotic. It is a member of hydrazines, a member of pyrazoles and a member of benzoic acids.|Eltrombopag is used to treat low blood platelet counts in adults with chronic immune (idiopathic) thrombocytopenia (ITP), when certain other medicines, or surgery to remove the spleen, have not worked well enough. ITP is a condition that may cause unusual bruising or bleeding due to an abnormally low number of platelets in the blood. Eltrombopag has also been recently approved (late 2012) for the treatment of thrombocytopenia (low blood platelet counts) in patients with chronic hepatitis C to allow them to initiate and maintain interferon-based therapy.|Eltrombopag is a Thrombopoietin Receptor Agonist. The mechanism of action of eltrombopag is as a Thrombopoietin Receptor Agonist, and Organic Anion Transporting Polypeptide 1B1 Inhibitor, and Breast Cancer Resistance Protein Inhibitor, and UGT1A1 Inhibitor, and UGT1A3 Inhibitor, and UGT1A4 Inhibitor, and UGT1A6 Inhibitor, and UGT1A9 Inhibitor, and UGT2B7 Inhibitor, and UGT2B15 Inhibitor. The physiologic effect of eltrombopag is by means of Increased Megakaryocyte Maturation, and Increased Platelet Production.|The thrombopoietin receptor agonists mimic the action of thrombopoietin on its receptor and stimulate the activation, proliferation and maturation of megakaryocytes, resulting in an increase in circulating platelet counts. Thrombopoietin itself acts in this manner, but when recombinant thrombopoietins were used clinically, they were found to cause rebound thrombocytopenia, probably due to induction of anti-thrombopoietin antibodies. For this reason, direct administration of thrombopoietin was abandoned as an approach to treating thrombocytopenia and other approaches to activating the thrombopoietin receptor were sought.|Eltrombopag is an orally active thrombopoietin receptor agonist with megakaryopoiesis stimulating activity. Eltrombopag binds to and stimulates the platelet thrombopoietin receptor (TPO-R or CD110), a member of the hematopoietin receptor superfamily. Activation of TPO-R leads to the proliferation and differentiation of megakaryocytes, thereby increasing the production of blood platelets.