Sildenafil (compound UK-92,480), sold under the trademark Viagra, Revatio and others, is a drug used to treat erectile dysfunction and pulmonary arterial hypertension (PPH). It was originally developed by British scientists and then brought to market by the pharmaceutical company Pfizer.1 It acts by inhibiting cyclic GMP-specific phosphodiesterase type 5 (PDE5), an enzyme that promotes the degradation of cGMP, which regulates the flow of blood in the penis. Since its availability in 1998, sildenafil has been the main treatment for erectile dysfunction, its main competitors in the market are vardenafil (Levitra) and tadalafil (Cialis).It was initially designed for use in high blood pressure and angina. The first clinical trials were conducted at the Morriston Hospital in Swansea, Wales. 2 During the phase I studies, conducted under the direction of Ian Osterloh, it was suggested that the drug had a slight effect on angina, but that could induce remarkable penile erections. Therefore, Pfizer decided to market it to treat erectile dysfunction, instead of angina. The drug was patented in 1996, and approved for use in erectile dysfunction by the United States Food and Drug Administration (FDA) on March 27, 1998. This became the first approved pill to treat erectile dysfunction in the United States, and there was offered for sale the same year.5 Immediately became a great success: annual sales of Viagra in the period 1999-2001 exceeded one billion dollars.
In contrast to the form of oral absorption of gastric absorption, whose maximum effect is reached one hour after ingestion, a chewable form of faster action has been developed, whose maximum effect is reached fifteen minutes after taking. The dose for the Treatment of pulmonary arterial hypertension is 20 mg three times a day.It has been documented that some sports professionals use drugs such as Viagra in the belief that they would improve their blood supply, improving their musculature and thus their sports performance. But sildenafil is exclusively vasodilator: it does not improve irrigation.The popularity of sildenafil among young males has grown over time.The commercial name of sildenafil, “Viagra”, has been widely integrated into popular culture, and knowledge of its effects has led to its recreational use. The reasons behind this use include the belief that the drug increases libido or improves the development of the sexual act.Studies of the effects of the drug when used without a prescription are limited, but suggest that it has little effect when it is used by those who do not suffer erectile dysfunction or among those stable sexual partners. Other studies show that a dose of 25 mg does not produce a significant change in the quality of the erection, but it can reduce the refractory time after ejaculation.In the same study a considerable placebo effect was documented in the control group. Alcohol: Alcohol can be taken with moderation in addition to this medication, as the excess can reduce its effects. In some cases it entails other effects that put health at risk. Food: Very heavy meals can reduce their effectiveness, especially foods rich in fat.
Driving: It may cause drowsiness, so it is not recommended to drive a vehicle or operate heavy machinery immediately after taking it. Women: Women should not take it, since its use has only been approved in the case of men with erectile dysfunction. Young people: There are currently people who make inappropriate use of the drug taking doses without needing them, especially young people. The consumption of non-prescription drugs should be avoided.Pregnancy: Keep in mind that sildenafil is not an aphrodisiac or helps to be more likely that a woman becomes pregnant. It only has an effect on erections.
I am medical practitioner from Cape Town. My professional interest: new treatments of erectile dysfunction.