Bosentas is used in the treatment of pulmonary hypertension (high pressure in the blood vessels of lungs). Bosentas relaxes the blood vessels of the lungs, which in turn lowers the blood. Bosentas is an endothelin receptor antagonist, prescribed for pulmonary atrial hypertension (high blood pressure in the lungs). Bosentas blocks the effects of endothelin-1 thereby decreases blood pressure in lungs. Bosentas also inhibits blood vessel thickening.

Bosentas is used to treat pulmonary arterial hypertension (PAH). It improves your ability to exercise and prevents your condition from getting worse.

More common side effects: fever, flu symptoms, swollen glands, feeling weak or tired; facial swelling; a red or blistering skin rash, severe tingling or numbness; cough, chest pain, trouble breathing; weight loss; or pain or burning when you urinate, lower back pain, swelling in your legs or feet.

This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider.

Do not use Bosentas if you are pregnant or think you might be pregnant. Bosentas can cause severe liver problems. Your liver function will need to be tested often.

Certain other medicines can interact with Bosentas and should not be used at the same time. Tell your doctor about all your current medicines.

It is not known whether Bosentas passes into breast milk or if it could harm a nursing baby. You should not breast-feed while using Bosentas.

Bosentas blocks a chemical in the blood that causes blood vessels to narrow. It comes as a tablet to take by mouth, with or without food. The recommended dose is 62.5 mg twice daily for 4 weeks. Maintenance dose is 125 mg twice daily.