How Do PAH Endothelin Antagonists Work?

How do PAH endothelin antagonists work?

PAH endothelin antagonists are medications used to treat pulmonary arterial hypertension (PAH), a condition of high blood pressure in the arteries that carry deoxygenated blood from the heart to the lungs. Endothelin antagonists reduce pulmonary hypertension by preventing constriction of the pulmonary arteries.

Endothelin-1 is a natural substance secreted by cells in the inner layer (endothelium) of blood vessels. Endothelin-1 causes vasoconstriction and induces proliferation of vascular smooth muscle cells by binding to ET-A and ET-B receptors, two types of protein molecules on vascular endothelial and smooth muscle cells.

Endothelin antagonists either selectively bind to ET-A or both ET-A and ET-B receptors and prevent endothelin-1 from activating them. Endothelin antagonists primarily dilate the pulmonary arteries and have little effect on systemic blood pressure because endothelin receptors are concentrated mainly in pulmonary blood vessels.

How are PAH endothelin antagonists used?

PAH endothelin antagonists are oral tablets prescribed for the treatment of the following conditions:


Orphan designation:

  • Idiopathic pulmonary fibrosis (scar tissue formation)
  • Systemic sclerosis (autoimmune connective tissue disease)
  • Fontan-palliated patients (Fontan palliation is a type of surgical procedure performed for a congenital heart condition)
  • Chronic thromboembolic pulmonary hypertension (CTEPH)

What are side effects of PAH endothelin antagonists?

Side effects of PAH endothelin antagonists may include the following:

Information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these drugs do not cause any harm when you take them along with other medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.

What are names of PAH endothelin antagonist drugs?

Generic and brand names of PAH endothelin antagonist drugs include:

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