A. Revatio (sildenafil) is an oral medication, taken 3 times daily. It was FDA-approved in 2005. Revatio works by relaxing and widening the blood vessels in the lungs so that it is easier for the heart to pump blood through the lungs. Revatio can help improve exercise capacity and well being. Revatio is also known as Viagra, the erectile dysfunction drug. However, Viagra is not FDA-approved for pulmonary hypertension. Revatio is.