The official name is Sildenafil
Citrate. Pharmaceutical chemists at Pfizer's research facility in
Kent, England originally conceived it as a treatment for
hypertension, angina, and other symptoms of heart disease. Clinical
trials during 1991 and 1992 revealed the drug was not great at
treating what it was supposed to treat, but eighty percent of male
test subjects were experiencing a side effect of erections.
It was finally approved by the US FDA in 1998 and the drug took US
markets by storm as a treatment for penile dysfunction and became an
overnight success. It and female Viagra now raise over two billion
dollars a year.