Pfizer, Microsoft take aim at illegal sildenafil sales and spam

Pfizer and software giant Microsoft have filed parallel lawsuits against web site operators and spam advertisers that sell illegal "generic" versions of sildenafil citrate (Viagra).

The two companies have filed a total of 17 actions against individuals involved in the sale and advertising of potentially dangerous medications unapproved by the FDA, Pfizer said.

In August 2004, Pfizer took legal action against 30 web sites selling "generic" sildenafil. Twenty-nine of those sites are no longer operating.