Revatio is a medication primarily used in the treatment of pulmonary arterial hypertension (PAH), a condition characterized by high blood pressure in the arteries that supply the lungs. Its active ingredient is sildenafil, which is also found in Viagra, a drug used to treat erectile dysfunction. However, Revatio is specifically formulated and dosed for the treatment of PAH. It works by relaxing blood vessels in the lungs, allowing blood to flow more easily and reducing the workload on the heart. Revatio is available in tablet form, as an oral suspension, and as an injectable solution. It is important for patients to follow their healthcare provider's instructions closely when taking Revatio, as it can interact with certain medications and conditions.