Viagra is a medication used to treat erectile dysfunction (ED) and pulmonary arterial hypertension (PAH). It is a phosphodiesterase type 5 (PDE5) inhibitor, which means that it works by increasing blood flow to the penis. This can help to improve erectile function in men with ED. Viagra is also used to treat PAH by relaxing the blood vessels in the lungs, which can help to improve blood flow and reduce symptoms such as shortness of breath and fatigue.
Viagra is available in tablet form and is taken orally. The usual dose is 50 mg, taken as needed before sexual activity. However, the dose may be increased to 100 mg or decreased to 25 mg depending on the individual’s response to the medication. Viagra should not be taken more than once per day.