The FDA does not have the legal authority to regulate the practice of the medicine, and the physician may prescribe a drug off label. Contrary to popular notion, it is legal in the United States and in many other countries to use drugs off label, including controlled substances such as opiates. Actiq, for example, is commonly prescribed off label even though it is a Schedule II controlled substance. While it would be legal for a physician to independently decide to prescribe a drug such as Actiq off-label, it is illegal for the company to promote off-label uses to prescribers. In fact, Cephalon, the maker of Actiq, was fined for illegal promotion of the drug in September 2008. Under the Food, Drug, and Cosmetic Act (FDAC) at U.S.C. 21 §§301-97, manufacturers are prohibited from directly marketing a drug for a use other than the FDA approved indication. The Food and Drug Administration Modernization Act of 1997 created an exception to the prohibition of off-label marketing. Manufacturers are now able to provide medical practitioners with off-label information in response to an unsolicited request.See Theresa Michele, FDA, for reference:
A physician, as you now, can for an individual patient, prescribe any drug that's on the market, for any patient, for any reason.