Clinical trials and subsequent clinical experience have demonstrated the efficacy of viagra indication in treating erectile dysfunction. The medication is typically taken on an as-needed basis, about 30 minutes to an hour before sexual activity, and its effects can last for up to four hours. Studies have shown that sildenafil improves erectile function in a significant proportion of men with ED, across various age groups and etiologies.

Viagra, under the name Revatio, is prescribed to improve exercise ability and delay clinical worsening in PAH patients. Besides treating ED, Viagra has also been explored for other medical conditions. It has shown potential in treating pulmonary arterial hypertension (PAH), a rare disease characterized by high blood pressure in the arteries of the lungs. Moreover, ongoing research investigates the possible role of Viagra in treating conditions such as heart disease, stroke, and even premature ejaculation, indicating its versatile therapeutic potential beyond erectile dysfunction.

The causes of ED are multifactorial and can include psychological issues, underlying health conditions such as diabetes and cardiovascular diseases, and lifestyle factors like smoking and obesity. Erectile dysfunction is a prevalent condition characterized by the inability to achieve or maintain an erection sufficient for satisfactory sexual performance. The drug is effective only with sexual stimulation, as it relies on the initial release of nitric oxide by the body.

PDE5, however, breaks down cGMP, thus inhibiting the ability to achieve or maintain an erection. By inhibiting PDE5, Viagra effectively increases the levels of cGMP, enhancing and prolonging erections in men suffering from ED. Nitric oxide is a crucial mediator in the relaxation of smooth muscle and vasodilation (widening of blood vessels), which are essential for achieving an erection. Viagra works by inhibiting the enzyme phosphodiesterase type 5 (PDE5), which breaks down cyclic guanosine monophosphate (cGMP), a molecule that promotes relaxation of the smooth muscle in the corpus cavernosum of the penis.

By inhibiting PDE5, sildenafil increases the levels of cGMP, leading to enhanced blood flow into the penis and facilitating the achievement and maintenance of an erection in response to sexual stimulation. The mechanism of action of Viagra is centered on its effects on the nitric oxide (NO) pathway within the penile tissue. Viagra is administered orally, typically in dosages ranging from 25 mg to 100 mg. It is advised to take the medication about one hour before sexual activity, and its effects can last up to four hours.

However, it is important to note that Viagra does not increase sexual desire; it only helps to maintain an erection when sexual stimulation occurs. Additionally, it should be used cautiously in individuals with cardiovascular risk factors. Viagra's interaction with other medications, particularly those containing nitrates used in heart disease treatment, can lead to dangerous drops in blood pressure.