Center for Drug Evaluation and Research, Food and Drug Administration. FDA proposes rules for dissemination information on off-label uses. FDA press release, June 5, 1998. Although physicians may prescribe any drug off-label, many are reluctant to do so. The reason for this is that they put themselves at more risk for a malpractice law suit.
Physicians make decisions to prescribe off-label based on clinical experience and clinical studies.
However, clinical studies may not reveal medication complications. Rare complications can arise, and result in law suits. While pulmonary hypertension was a known side-effect of fenfluramine, heart valve damage was not. For more on the pitfalls of off-label prescribing and other perspectives, see the articles below. Free speech for medicine.