Results of a survey published in Pharmacoepidemiology and Drug Safety suggest that some doctors in the US incorrectly think certain off-label uses of prescription drugs are approved by the FDA. Lead author G. Caleb Alexander noted that "this mistaken belief could encourage doctors to prescribe the drugs, despite the lack of scientific evidence supporting such use."

The survey involved 599 primary care doctors and 600 psychiatrists who were asked to review a list of drugs and indications that varied in their FDA approval status and levels of supporting evidence. Results showed that the average respondent was able to accurately identify the approval status of just over half of the drugs. The researchers also noted that accuracy was found to increase "modestly" when limited to drugs the physician had prescribed during the last 12 months.

Furthermore, the study found that confusion over FDA-approval status was greatest with psychiatric drugs. Data showed that one in five physicians who had previously prescribed AstraZeneca's Seroquel (quetiapine) to treat patients with dementia and agitation thought incorrectly it was approved for this indication. Similarly, one in three doctors who prescribed lorazepam to treat chronic anxiety thought it had been authorised for this use. The product label for each drug advises against the corresponding off-label use cited in the survey results.

The researchers concluded that the study's findings "highlight a pressing need for more effective methods to inform physicians about the evidence base, or lack thereof, for drugs they prescribe off label."

Reference Articles

U.S. physician knowledge of the FDA-approved indications and evidence base for commonly prescribed drugs: results of a national survey - (Pharmacoepidemiology and Drug Safety)

Disparities: Study finds risk in off-label prescribing - (The New York Times)

Doctors unaware of many drug approval uses - (Times of the Internet)