What is Viagra?

Viagra: How Does It Work?
Impotence, or erectile dysfunction, is a common complaint among men, perhaps affecting as many as 30 million men in the United States. For those afflicted, normal sexual intercourse is difficult, if not impossible because of an inability to achieve or maintain an erection. Many who suffer from impotence received some very promising news this last Spring when the FDA approved the use of Viagra for the treatment of erectile dysfunction.
An example of the popularity of this drug, for which 250,000 prescriptions were written just in the last week of April, can be demonstrated by a search of the Internet. Such a search will yield over 7000 pages, although many of these seem to be companies trying to sell the drug over the web. Many print and on-line articles have documented the meteoric success of this drug and delved into the medical and social implications of its use. Links to some useful articles are listed below. However, what I will do in thi...