During the drug approval process, the Food and Drug Administration (FDA) requires substantial evidence of efficacy and safety for specific clinical situations. The FDA’s Center for Drug Evaluation and Research establishes the proper indications for a drug based on a critical analysis of the drug’s clinical trial results. If the FDA is confident that the drug is safe and effective, the drug's manufacturer, in collaboration with the FDA, agrees upon specific language describing route of administration, dosage, and other information to be included on the drug's label. Following this agreement of intended usage, the FDA’s Division for Drug Marketing, Advertisement, and Communication (DMAC) continues to regulate the pharmaceutical industry, with the intention of ensuring that off-label usage is not promoted. Although drug approval is indication-specific and DMAC regulates pharmaceutical companies, the FDA actually plays a limited role once a drug is on the market, as they have no authority to regulates physicians.
While off-label prescribing can be beneficial at times, it is many times accompanied by dangerous side effects. Technically speaking, off-label prescribing isn’t illegal if it is done by a physician, but it is oftentimes done in the absence of adequate supporting data. According to an article in the New England Journal of Medicine, off-label uses have not been formally evaluated, and evidence provided for one clinical situation may not apply to others. Archives of Internal Medicine showed that "for the 3 leading drugs in each of the 15 leading drug classes, off-label use accounted for approximately 21% of prescriptions. The highest rates of off-label use were for anticonvulsants (74%), antipsychotics (60%), and antibiotics (41%). In an examination of off-label prescribing of 160 common drugs, off-label use was also found to account for 21% of all prescriptions, and most off-label drug uses (73%) were shown to have little or no scientific support." Atypical antipsychotics and antidepressants were particularly likely to be used off-label without strong evidence.
In 1993, the FDA approved Pfizer manufactured, Neurontin for the treatment of seizures. According to the Archives of Internal Medicine, "Pfizer subsidiary Warner-Lambert used activities not usually associated with sales promotion, including continuing medical education and research, to promote Neurontin, so that within 5 years the drug was being widely used for the off-label treatment of pain and psychiatric conditions." Following years of off-label marketing, Warner-Lambert was ordered to pay $430 million in damages, after admitting to charges that it violated FDA regulations by promoting the drug for psychiatric conditions, pain, and other unapproved uses.