Eighty-five percent of the 725 million total prescriptions given for the 500 drugs in 2001 were either for FDA-approved indications or off-label uses with strong scientific support. However, an estimated 150 million (21 percent) of the prescriptions were for off-label uses and most (73 percent, or 15 percent of total prescriptions) of those lacked scientific support. Cardiac medications (46 percent), anticonvulsants (46 percent) and medications used to treat asthma (42 percent) were the most likely to be prescribed off-label. Psychiatric drugs were highly likely to be prescribed off-label with limited or no scientific support (96 percent vs. 4 percent strong support), as were allergy medications (89 percent vs. 11 percent strong support).
Some off-label uses followed logically from FDA-approved indications, the authors write, such as prescribing asthma medications for other lung diseases. However, other off-label prescriptions were for conditions dramatically different from those for which the drug was approved to treat, such as the use of an anticonvulsant drug for chronic pain. "Differentiating off-label situations that are clinically reasonable from those that may be of concern is an essential first step," the authors write.
"The ability to prescribe medicines off label brings greater latitude to turn scientific knowledge into innovative clinical practice," they conclude. "Although attention should be given to the situations where evidence-based off-label use is clinically beneficial, policy makers must begin to consider strategies for mandatory postapproval surveillance that focus on curtailing underevaluated off-label practices that jeopardize patient safety or represent economically wasteful prescribing practices."
Contact: Rosanne Spector
JAMA and Archives Journals