Then there's the issue of off-label promotion. A drug's "label" is the drug's FDA-approved prescribing information--those complicated package inserts that we've all seen. Any approved use is on-label, while any use not listed on the insert is considered off-label, even though the off-label use may effectively treat a medical condition. Although the FDA tolerates off-label usage, it forbids pharmaceutical companies from promoting such uses.
Promotion is really just communication. So the ban on promotion means that your doctor is prohibited from getting any useful information from the company that manufactures the drug he is preparing to inject into your veins, if he is using the drug for off-label purposes. This prohibition on communication does real harm to real people, to say nothing of the harm that it does to the First Amendment. And it isn't just Forest that has fallen afield of this rule; over the last three years, Pfizer was hit with an eye-popping $2.3 billion settlement; Eli Lilly paid $1.4 billion; Novartis paid $422 million; Allergan paid $600 million; Elan paid $204 million; and GlaxoSmithKline has set aside $3.4 billion for its settlement.
This is from Charles L. Hooper and David R. Henderson, "The FDA's War on Drugs," published at the Hoover Institution's Defining Ideas.