Sildenafil is a prescription medication mostly used to treat erectile dysfunction, and sometimes used to treat hypertension (high blood pressure). Sildenafil is in a class of medications known as phosphodiesterase-5 (PDE) inhibitors.
Sildenafil is available as a generic drug, as well as under various patented names. The most common brand names in North America for sildenafil are Viagra (marketed for erectile dysfunction) and Revatio (marketed for pulmonary arterial hypertension). In India, the most common brand name for sildenafil is Caverta.
Sildenafil is a vasodilator; this means that it makes blood vessels become wider; it also lowers the pressure of the blood going through the blood vessels. Sildenafil mostly works in the penis and lungs.
This medicine is mostly used to increase blood flow to the penis. This helps the penis become erect during sexual intercourse.
Sildenafil also helps pulmonary hypertension. Because this medicine makes the blood vessels wider, it makes it easier for blood to flow.
The use of sildenafil for either condition carries the risk of priapism (an erection that won't go away for hours, and which can lead to permanent damage to the penis). If an erection has persisted for four or more hours, it is recommended to go to an urgent medical care clinic or hospital emergency room.
Sildenafil has many other potential side effects, including sudden loss of vision in one or both eyes.
It can be dangerous to take sildenafil with beta blocker drugs, and should be avoided, as they both lower blood pressure and extreme hypotension can result. It can also be dangerous to those with pre-existing heart problems.
Sildenafil was patented by Pfizer in 1996. It gained FDA approval in March, 1998, and was first distributed by Pfizer in 1998 under the brand name Viagra.
