|Elimination half-life||15 hours (terminal)|
|CompTox Dashboard (EPA)|
|Chemical and physical data|
|Molar mass||378.421 g/mol g·mol−1|
|3D model (JSmol)|
Ambrisentan (U.S. trade name Letairis; E.U. trade name Volibris; India trade name Pulmonext by MSN labs) is a drug indicated for use in the treatment of pulmonary hypertension.
The peptide endothelin constricts muscles in blood vessels, increasing blood pressure. Ambrisentan, which relaxes those muscles, is an endothelin receptor antagonist, and is selective for the type A endothelin receptor (ETA). Ambrisentan significantly improved exercise capacity (6-minute walk distance) compared with placebo in two double-blind, multicenter trials (ARIES-1 and ARIES-2).
Last Updated 9/2/2015
|8/15/2015 Reprod. Toxicol.||Endothelin receptor activation mediates strong pulmonary vasoconstriction and positive inotropic effect on the heart. These physiologic effects are vital for the development of the fetal cardiopulmonary system. As such, endothelin receptor antagonists such as Ambrisentan are teratogenic.|
|8/27/2015 NEJM||Ambrisentan when used in combination therapy with Tadalafil was found to be more efficacious in treating treatment naive patients with WHO class II or III Pulmonary Arterial Hypertension than monotherapy using either drug.|
Ambrisentan is indicated for the treatment of pulmonary arterial hypertension (WHO Group 1) in patients with WHO class II or III symptoms to improve exercise capacity and delay clinical worsening.
Endothelin receptor activation mediates strong pulmonary vasoconstriction and positive inotropic effect on the heart. These physiologic effects are vital for the development of the fetal cardiopulmonary system. In addition to this, endothelin receptors are also known to play a role in neural crest cell migration, growth, and differentiation. As such, endothelin receptor antagonists such as Ambrisentan are known to be teratogenic.
Ambrisentan has a high risk of liver damage, and of birth defects if a woman becomes pregnant while taking it. In the U.S., doctors who prescribe it, and patients who take it, must enroll in a special program, the LETAIRIS Education and Access Program (LEAP), to learn about those risks. Ambrisentan is available only through specialty pharmacies.