Uses

Bosentan is an endothelin receptor antagonist indicated for treatment of pulmonary arterial hypertension (WHO Group 1) in adults to improve exercise capacity and delay clinical worsening, and in pediatric patients aged 3 years and older with idiopathic or congenital PAH.

Do not use if

Contraindicated in pregnancy due to teratogenicity, in patients receiving cyclosporine A or glyburide, and in those with known hypersensitivity to bosentan.

Side effects

Common adverse reactions (≥3% over placebo) include nasopharyngitis, flushing, leg edema, anemia, and elevated liver aminotransferases. Hepatotoxicity and fluid retention are important serious adverse effects.

Warnings

Black box warning: risk of hepatotoxicity (requires regular liver function monitoring) and embryo-fetal toxicity (requires pregnancy testing and contraception). Available only through a restricted REMS program.

How it works

Bosentan competitively antagonizes both ETA and ETB endothelin receptors with slightly higher affinity for ETA. By blocking endothelin-1 signaling, it reduces pulmonary vascular resistance and decreases pulmonary arterial pressure, improving hemodynamics.

Storage

Store at room temperature 20°C–25°C (68°F–77°F) in the original packaging.