Endothelin antagonists are used to treat pulmonary arterial hypertension (PAH). These medications work by blocking the action of endothelin, a substance in your blood that causes blood vessels to narrow, which helps to lower blood pressure in the lungs and improve your ability to exercise. Endothelin antagonists are available in oral forms. Examples include ambrisentan (Letairis), bosentan (Tracleer), and macitentan (Opsumit). You and your prescriber can choose the form that best fits your needs.
