Viagra, for example, became "a well-known Pfizer drug for men, technically known as sildenafil citrate."

He was a paid member of the company's speakers bureau, giving talks about Pfizer drugs to colleagues.

The Pfizer drug, Trovan was used in a clinical trial in Nigeria.

Lipitor, another Pfizer drug, is the best-selling drug in the world, with sales of $13 billion this year.

To get free Pfizer drugs through a doctor, a patient must have an income of less than $16,000, or $24,000 for a couple.

Some analysts said the Pfizer drug appeared to work better but had more serious side effects.

There is also a certain marketing advantage in getting people to switch to Pfizer drugs from other manufacturers' drugs.

And while the data on the two drugs are not directly comparable, the Pfizer drug appears to be more powerful but also more toxic.

It's almost enough to drive marketers to another Pfizer drug, Xanax.

The two Pfizer drugs and Vioxx belong to a class of drugs known as cox-2 inhibitors.