What is Viagra and How does it work?

Viagra, discovered by Pfizer, is a widely recognized medication primarily used for the treatment of erectile dysfunction. The active ingredient in Viagra is a compound called sildenafil citrate. It works by interacting with an enzyme in the body known as phosphodiesterase type 5 (PDE5). Normally, PDE5 breaks down a compound called cyclic guanosine monophosphate (cGMP), which is responsible for relaxing smooth muscle tissue. By inhibiting PDE5, sildenafil citrate allows cGMP to remain in the system longer, promoting prolonged muscle relaxation.

The role of Pfizer in Viagra's discovery

Pfizer, a global pharmaceutical company, discovered sildenafil citrate and its potential benefits for treating erectile dysfunction. This compound has a unique ability to fit into the PDE5 enzyme and effectively disable it, leading to enhanced cGMP circulation.

Understanding phosphodiesterase type 5 (PDE5)

PDE5 is an enzyme that plays a crucial role in the regulation of blood flow within the body. It works by breaking down cGMP, a compound that promotes the relaxation of smooth muscles in areas such as the corpus cavernosum. By doing so, it controls the dilation and constriction of blood vessels. However, when PDE5 is inhibited, cGMP can circulate freely, leading to increased blood flow in certain areas.

The function of cyclic guanosine monophosphate (cGMP)

cGMP is a crucial compound in the body that is responsible for promoting the relaxation of smooth muscle tissue. When present in the corpus cavernosum, it can facilitate an increase in blood flow. The enhanced levels of cGMP, thanks to the inhibition of PDE5 by sildenafil citrate, contribute to the erection mechanism.

The corpus cavernosum and its role in blood flow

The corpus cavernosum is a sponge-like region within the penis that fills with blood during an erection. The relaxation of the smooth muscle tissue in the corpus cavernosum, promoted by the presence of cGMP, is a key factor in achieving and maintaining an erection.

Sildenafil Citrate: The active compound in Viagra

Sildenafil Citrate is a cGMP-selective phosphodiesterase type 5 inhibitor, which means it specifically targets and inhibits the PDE5 enzyme. By doing so, it allows cGMP to persist in the body longer, thereby enhancing blood flow.

How Sildenafil Citrate affects PDE5 and cGMP

Sildenafil citrate's inhibition of PDE5 leads to an increased presence of cGMP in the body. This is because PDE5's primary function is to break down cGMP in the body. When PDE5 is inhibited, cGMP levels increase. This leads to further relaxation of the smooth muscle tissue and enhanced blood flow, particularly in the penis.

Use of Sildenafil Citrate in treating erectile dysfunction

Erectile dysfunction is a common condition where men have difficulty achieving or maintaining an erection. Sildenafil citrate, by inhibiting PDE5 and allowing cGMP to persist, improves blood flow to the penis and aids in achieving an erection.

Use of Sildenafil Citrate in treating pulmonary arterial hypertension

Sildenafil citrate is also used to treat pulmonary arterial hypertension, a condition characterized by high blood pressure in the arteries leading to the lungs. By enhancing the effect of nitric oxide, a chemical released in response to sexual stimulation, sildenafil citrate can improve blood flow in these arteries.

Chemical Release due to Viagra

Viagra does not directly release any chemicals.

However, its active ingredient, sildenafil citrate, enhances the effect of nitric oxide—a chemical naturally released