160 Common U.S. Food and Drug Administration (“FDA”) approved drugs which are used for “off label” purposes represent approximately 21 percent of all prescriptions in the United states. Physicians may prescribe FDA approved drugs for any therapeutic use that is appropriate in their medical judgment. The FDA, however, prohibits pharmaceutical companies and their employees from promoting the use of FDA approved drugs for “off label” use. Although there is no express prohibition in the Food Drug and Cosmetic Act or its regulations prohibiting the promotion of drugs for off label use, the government uses a criminal statute which prohibits the introduction of “misbranded” drugs into interstate commerce ( 21 U.S.C. 331(a) and 333(a)(1) to prosecute pharmaceutical companies, their employees and sometimes physicians who are “promoting” the off-label use of drugs.