How Sildenafil Citrate Works

Sildenafil citrate has two medical uses: it is marketed as Viagra to treat erectile dysfunction (ED), or impotence, in men and as Revatio to treat pulmonary arterial hypertension (high blood pressure in the lungs).

Sildenafil inhibits phosphodiesterase type 5, an enzyme that metabolizes cyclic guanosine monophosphate. It enhances the cyclic relaxation and growth inhibition of vascular smooth-muscle cells controlled by a chemical in the body called guanosine monophosphate. In common English, this means that sildenafil opens the blood vessels so that blood can flow more easily to tissues that need it.

As Viagra, sildenafil citrate increases blood flow to the penis, allowing a man to achieve and sustain an erection that lasts long enough to engage in sexual activity. For men affected by ED, this is critical to relationships in which sex is an important factor. As Revatio, sildenafil enables normal blood flow through the lungs, easing the symptoms of pulmonary hypertension and improving breathing function.

References

• Viagra.com
• Drugs.com
• The New England Journal of Medicine