Short of being taken off the market, a black box warning (aka. boxed warning and black label warning) is the most severe type of warning the U.S. Food and Drug Administration (FDA) issues over safety concerns about a medication. Black box warnings alert consumers and healthcare providers that a medication may cause serious side effects or poses life-threatening risks.
The warning appears on printed materials inside the drug's packaging, on materials made available to doctors who may prescribe the medication, and on print advertising such as in magazines. It is surrounded by a printed black rectangle, thus its name.
Prior to the Food and Drug Administration Amendments Act of 2007 (FDAAA), the FDA could only request that black box warnings be implemented. The FDA, however, can now mandate these warnings, and the economic implication of this for drug companies is significant. A drug that gets a black box warning is often prescribed about 90 percent less frequently than prior to the warning. This is in large part because doctors are more reluctant to prescribe black box labeled drugs because of the increased likelihood of a malpractice lawsuit based on practicing medicine "outside the norm".
One of the FDA's first uses of the new authority was to require a black box warning for older, conventional antipsychotics. Other examples of drugs for which a black box warning has been required under the FDA's new authority include:
- Flouroquinolone antibiotics such as ciprofloxacin (Cipro) and levofloxacin (Levaquin) for an increased risk of tendon ruptures (July 2008)
- Rosiglitazone (Avandia), a diabetes medication, for an increased chance of heart failure or heart attack in certain cases (November 2007)
- SSRI antidepressants such as sertraline (Zoloft), paroxetine (Paxil), escitalopram (Lexapro), and other antidepressants for an increased risk of suicidality in young adults ages 18 to 24 (May 2007)
The FDA can also now require a drug company to create medication guides showing consumers how to safely use a specific medication. They also contain information the FDA must approve that can help consumers avoid serious adverse events.
The guides are intended to be given out by pharmacists when prescriptions are filled. They are also available online on FDA and the drug company's websites.