Inhaled treprostinil is a medication used in the treatment of pulmonary arterial hypertension (PAH). It is a synthetic form of prostacyclin, a naturally occurring substance in the body that helps to dilate blood vessels and improve blood flow. Inhaled treprostinil works by helping to relax and widen the blood vessels in the lungs, which can help to reduce the symptoms of PAH such as shortness of breath, chest pain, and fatigue. Inhaled treprostinil is administered using a small, portable inhaler device that delivers the medication directly to the lungs. This method of delivery allows for higher concentrations of the medication to reach the affected areas of the lungs, compared to oral or intravenous forms of treprostinil. Research in this area typically focuses on the effectiveness and safety of inhaled treprostinil in treating PAH, as well as exploring its potential use in other pulmonary conditions. Studies may also investigate optimal dosing regimens, long-term effects, and potential side effects of inhaled treprostinil therapy.