Bosentan mechanism of action?

How does bosentan work in the body?

Bosentan is an oral drug that blocks endothelin receptors. It works by antagonizing both endothelin receptor types, ETA and ETB, which prevents endothelin-1 from activating these receptors.[1]

Endothelin-1 is a signaling molecule involved in blood vessel narrowing (vasoconstriction) and can also contribute to vascular remodeling. By blocking its receptors, bosentan reduces vasoconstriction and helps improve blood flow in conditions where endothelin-driven pulmonary hypertension is a problem.[1]

What does ETA vs ETB blockade mean for effects?

Because bosentan blocks both ETA and ETB receptors, it can reduce endothelin effects mediated through either receptor subtype.[1]

This dual blockade is part of why bosentan is used for pulmonary arterial hypertension: the medication counteracts endothelin-mediated narrowing and high pulmonary vascular resistance.[1]

Where is bosentan used because of this mechanism?

Bosentan’s endothelin-receptor antagonism is the basis for its use in pulmonary arterial hypertension, a disease state in which endothelin signaling plays a major role in increased pulmonary artery pressure.[1]

Sources:
1. https://www.drugs.com/mechanism-of-action/bosentan.html