Treprostinil sodium is primarily used in the treatment of pulmonary arterial hypertension (PAH), a condition characterized by high blood pressure in the arteries of the lungs. It helps to improve exercise capacity and reduce symptoms such as shortness of breath by dilating blood vessels, thereby improving blood flow and reducing the workload on the heart.

This medication is often administered via continuous intravenous or subcutaneous infusion, though oral and inhaled forms are also available. It is particularly beneficial for patients who do not respond adequately to other therapies. Additionally, treprostinil sodium is sometimes used in the management of other conditions involving poor blood circulation, such as severe Raynaud's phenomenon, where it helps to alleviate symptoms by improving blood flow to the extremities.

Its use requires careful monitoring by healthcare professionals to manage potential side effects and ensure optimal dosing.