Viagra turns thirteen

27^th March this day in 1998, the Food and Drug Administration (FDA) approved the drug Viagra, Later that year; it was approved for sale on the European market by the European Commission.

The main ingredient of Viagra – the chemical sildenafil – was initially being trialled as a treatment for angina. But researchers at Pfizer soon found that, while sildenafil had nominal effect on angina patients, it was highly effective at inducing erections. The reaction took about an hour, a little longer if the pill was taken after eating fatty foods. Seeing the economic opportunity in such a biochemical effect, Pfizer decided to market the drug for male impotence also know as erectile dysfunction.

 
When Viagra was first marketed, erectile dysfunction was a condition that was under-recognised by most members of the public. So in order to increase awareness, Pfizer recruited ex-US Presidential candidate Bob Dole to act as a spokesperson for Viagra in advertisements. This post would later also be filled by the Brazilian football legend Pele.

The popularity of Viagra would eventually inspire Pfizer’s competitors to create their own erectile dysfunction treatments. The first of these to be approved was Levitra, which was co-marketed by GlaxoSmithKline (GSK), Bayer and Schering-Plough in August 2003. In October 2003 another erectile dysfunction medication called Cialis, marketed by GSK, was approved.

All three erectile dysfunction medications have been used by millions of men worldwide. Viagra sales in 2010 alone were around $1.9 billion. Next year Pfizer will face an important milestone – the expiration of Viagra’s American patent. In parts of the world where Viagra does not have a valid patent, such as China, genetic versions of Viagra are already available under names such as Kamagra and Caverta. Once the US patent is up (providing Pfizer is unable to obtain an extension), generic versions of Viagra may begin to become a significant rival to the branded drug.