DREW GRIFFIN, CNN INVESTIGATIVE CORRESPONDENT: Pfizer, Incorporated, with 116,000 employees and revenues of $50 billion a year, is the world's largest pharmaceutical company. The government was building a case against Pfizer for fraudulently marketing a drug that had raked in hundreds of millions of dollars in profits, a painkiller called Bextra. Pfizer aggressively marketed it for uses and in doses not approved by the FDA. But our investigation found another story, ... about the power major pharmaceutical companies have, even when they break the laws intended to protect patients. In 2001, ... the FDA approved Bextra, but only for limited use and only for menstrual cramps and arthritis. Even so, Pfizer sales reps promoted it, illegally, for surgical pain in higher doses, uses the FDA had rejected due to safety concerns. Doctors responded. Instead of prescribing, say, ibuprofen at pennies a pill, they prescribed Bextra at nearly $3 a pill for all kinds of unapproved uses. Sales were very good. GLENN DEMOTT, FORMER PFIZER SALES REP: They said that the district manager approved it. They think it might not be legal, but if they don't make their numbers, they're not going to keep their job anyway. GRIFFIN : It brought Pfizer nearly $1 billion in profits. And it cost us all, because Medicare, Medicaid, and our private insurance picked up much of the tab. MICHAEL LOUCKS, FORMER FEDERAL PROSECUTOR: If the company is able to push the product for the unapproved indication, then it makes a mockery, if you will, of the FDA approval process.