What is Viagra (sildenafil) used for?

Viagra is a prescription medicine that is used to treat erectile dysfunction. It helps in achieving and maintaining an erection when aroused to enable satisfactory sexual intercourse.

How does Viagra (sildenafil) work?

Viagra (sildenafil) is a PDE-5 inhibitor. It blocks an enzyme called phosphodiesterase-5 (PDE-5). This leads to a relaxation of the muscles and widening of the blood vessels in the penis. This, in turn, leads to increased blood flow to the penis. Viagra thus helps achieve and maintain an erection by increasing penile blood flow. However, the drug only works in the presence of sexual arousal. 

What are Viagra (sildenafil) doses?

Viagra is available in oral tablet form. Common Viagra doses are 25 mg, 50 mg, and 100 mg.

A typical Viagra dose is 50 mg by mouth one hour prior to anticipated sexual activity. Viagra may not be a good option for some people because of the lack of spontaneity. The dose can be adjusted between 25 mg and 100 mg, depending on the response. You should not take Viagra more than once a day at any dose. 

Sildenafil is also used to treat pulmonary hypertension in adults over the age of 18 under the brand name Revatio. Revatio is available as an oral suspension (liquid) and oral tablet.