According to the Department of Justice, Wyeth - which was acquired by Pfizer, Inc., in 2009 - was illegally marketing the drug for uses that had not been approved "as safe and effective by the Food and Drug Adminitration."

The department said the drug is an "immunosuppressive" that ensures the body's immune system does not reject a transplanted organ.

'We will hold them accountable

"FDA's drug approval process ensures companies market their products for uses proven safe and effective," said Stuart F. Delery, acting assistant attorney general for the Justice Department's Civil Division. "We will hold accountable those who put patients' health at risk in pursuit of financial gain."

Under provisions of the federal Food, Drug and Cosmetic Act (FDCA), pharmaceutical companies must specify the uses of medications in all new drug applications to the FDA.