Viagra Active Ingredients

Ben Ikenson, author of the book "Patents," describes Viagra as the primary drug used by erectile dysfunction sufferers to produce and maintain the best possible erections. Ikenson explains that in response to a sexuality study by Masters and Johnson, Pfizer developed a drug with the single active ingredient sildenafil citrate to approach some of the concerns raised in the study.

Function

In "Patents," Ikenson explains that sildenfil citrate works by dilating arteries leading to the penis while contracting veins leading away from the male pubic area. In this way, Viagra can help men produce fuller and longer-lasting erections. In the book "Sildenafil," Udo Dunzendorfer asserts that although sildenafil citrate effectively assists men in producing erections, it does not actually cause the erections, but rather renders them more easily achieved. Thus, Viagra requires arousal to garner results.

Efficacy

Udo Dunzendorfer notes that clinical trials predicted highly positive results for the use of sildenafil citrate. Even those with severe physical complications that would otherwise not allow any sexual capacity, such as those with severe diabetes or neurologic complications, exhibited high success rates in engaging in sexual intercourse following the consumption of sildenafil citrate. The same clinical trials suggested that sildenafil citrate was both safe and effective for those with cardiac disorders, despite sildenfanil citrate's suspected effect on diastolic blood pressure due to the dilation of arteries.

Side Effects

According to Dunzendorfer, side effects of sildenafil citrate emerged in clinical trials in small proportions, though the effects were sustained throughout the duration of the chemical's influence. These effects include headache, symptoms of dilated arteries, dizziness, indigestion, nose inflammation and defective vision, usually in the form of a blue tint. In all patients, these side effects gradually disappeared with continued use. Test subjects exhibited an increasing tolerance for the drug, but this did not compromise the drug's effectiveness.