The medicine that we are familiar with today as Viagra started out as a compound called Sildenafil citrate, which was on trial to treat patients with angina in the 1980s, at Pfizer’s largest European research centre at Sandwich, Kent. One noticeable side-effect of this compound was the increase in frequency and length of erections reported by test patients, and after further research it was decided to concentrate on this side-effect and try and produce a drug to combat erectile dysfunction. So in May 1994 Pfizer began the first tests using Sildenafil citrate purely to teat erectile dysfunction. At first, only 12 men were given the compound, but when 10 out of those 12 reported excellent results the potential of Viagra was realised.
More trials took place between September 1994 to February 1995. This new area of research required new testing standards as nothing like this had been done before, so an in-depth questionnaire was developed to judge the effectiveness of the Sildenafil on the out-patients who were testing it. This was a blind test, which means that the men did not know what they were being given and one group had only an inert placebo. In this trial, the levels of reported success were as follows: 29% of the placebo group; 65% of the men in the group who took the 25mg dose; 79% of those taking 50mg; and a huge 88% of those taking the 100mg dose.
After this, open trials were the next step, which is when patients are told exactly what they are taking. 36 hospital urological departments in both the UK and Sweden carried out testing on patients, assessing a total of 225 men. After the 32 week trial was complete, Sildenafil was shown to be successful in 88% of users. When asked if they wanted to continue with the trial, more than 90% of the patients said yes.
Since the FDA approved Viagra in 1998, it has undergone countless more trials by Pfizer, who are not content to rest on their laurels and seek to continually explore more about Viagra. The fact that it is easy and simple to take, works quickly and effectively, and has a short half-life which means that its actions on the body are complete in an average of four hours, makes it an ideal choice for the millions of men who experience erectile dysfunction. It has now been approved for use by 118 regulatory bodies in 118 different countries around the world, and now per year there are an estimated 120 million prescriptions written for it.