Model prioritizes which drugs used off-label should be studied first
Research Activities, May 2009, No. 345
After drugs go through rigorous clinical trials for determination of safety and efficacy, the U.S. Food and Drug Administration (FDA) approves the product and allows it to be labeled and marketed to treat specific conditions. Some clinicians, however, prescribe drugs to treat conditions for which they have not been approved. This practice, called "off-label" prescribing is allowed as part of the practice of medicine. However, in some cases there is little or no evidence as to the effectiveness or safety of this off-label use.
Surrey M. Walton, Ph.D., and colleagues at the Chicago-Area Developing Evidence to Inform Decisions about Effectiveness (DEcIDE) Center, under an Agency for Healthcare Research and Quality contract (290-2005-0038), developed a model to prioritize research on drugs currently being used off-label. The model applies quantitative measures of the absolute number of off-label uses for a drug, the scientific evidence for the drugs' off-label use, safety concerns, marketing activity, longevity, and drug cost.
The researchers identified 14 drugs, mainly antidepressants and antipsychotics, that were most worthy of further research, such as systematic comparisons of the available evidence. For instance, the atypical antipsychotics quetiapine, risperidone, and olanzapine are all approved to treat schizophrenia. However, they are also commonly prescribed off label to treat bipolar disorder and depression, even though the FDA has approved quetiapine and risperidone only for when a patient with bipolar disorder is experiencing a manic or depressive episode.
The authors recommend policymakers place a greater emphasis on comparative effectiveness studies for these off-label uses and require greater scrutiny of marketing efforts that encourage physicians to prescribe drugs off label. Finally, policymakers could call for diagnosis to become part of the prescription record to facilitate comparative effectiveness research of off-label uses. Electronic health records that capture documentation of a diagnosis for every prescribed drug could be useful tools in that endeavor.
For more information about DEcIDE and the Effective Health Care program, please visit http://effectivehealthcare.ahrq.gov.
See "Prioritizing future research on off-label prescribing: Results of a quantitative evaluation," by Dr. Walton, Glen T. Schumock, Pharm.D., M.B.A., Ky-Van Lee, Ph.D., and others in the 2008 Pharmacotherapy 28(12), pp. 1443-1452.