Ambrisentan

Overview
Ambrisentan (U.S. trade name Letairis) is a drug being researched for use in the treatment of pulmonary hypertension.

It functions as an endothelin receptor antagonist, and is selective for the type A endothelin receptor (ETA).

Ambrisentan was approved for sale by the U.S. Food and Drug Administration (FDA) on June 15, 2007 for the once-daily treatment of pulmonary arterial hypertension. The Marketing Authorisation Application is under review by the European Medicines Agency. Ambrisentan had previously been designated an orphan drug by both the FDA and the European Commission, in August 2004 and May 2005 respectively.