OKLAHOMA CITY - The Department of Justice released details in a lengthy healthcare investigation involving the pharmaceutical company Pfizer.

A company it purchased, Wyeth Pharmaceuticals, unlawfully marketed a prescription drug. The company violated FDA regulations when it marketed Rapamune, a drug used for transplant patients.

Now Pfizer is on the hook for $491 million.

Rapamune is a drug that prevents the body's immune system from rejecting a organ transplants.

The FDA approved Rapamune in 1999 only for kidney transplant patients and with other restrictions. But federal prosecutors say at the time Wyeth pharmaceuticals marketed Rapamune to liver, heart, and other transplant patients, against FDA regulations.

"92 percent of the doctors who prescribed Rapamune for off-label use had been contacted by Wyeth sales representatives at some point," U.S. Attorney Sanford Coats said.

The FBI and several other agencies investigated Wyeth for years. Prosecutors say the company's sales reps were given bonuses to target all transplant patients, even though it was unsafe.

Pfizer now owns Wyeth. The drug maker pleaded guilty on Tuesday, agreeing to pay more than $230 million in criminal fines and forfeitures.

Investigators hope this case will deter other drug makers from putting people's lives at risk just to make a profit.

"That's because real people rely on this system for their medical needs, and that makes it a matter of life and death," FBI Special Agent James Finch said.

There will also be a payout of $700,000 to the Medicaid system here in Oklahoma.

The company has 10 days to pay the fines.

Every state in the country will receive money as part of the civil settlement totaling nearly $260 million.