A Happy, Elderly Couple

Viagra Development

Due to early research in to the compounds that affect our blood vessels the scientists did not set out to produce the biggest selling impotence drug, but to find a cure for heart conditions. In 1991 at the development site for Pfizer in Kent, England, Andrew Bell, Dr David Brown and Dr Nicholas Terrett discovered that there were chemical compounds belonging to pyrazolopyrimidone that would be useful to treat heart conditions such as angina. This became know as Sildenafil and on the patent application it was named as a heart medicine. After the patent was passed there were extensive clinical trials to make sure the medicine was safe to release. It was during these trials that Terrett and Peter Ellis discovered that when Sildenafil was used as a heart medicine it also increased the blood flow to the penis. Therefore it was tested as a drug to treat impotence or erectile dysfunction instead. The way in which it works is that it enhances the natural effect of nitric oxide that is the natural chemical released in response to sexual stimulation. After this discovery Peter Dunn and Albert Wood worked on the 9 step process to synthesis Sildenafil into an oral pill.