What is a Black Box Warning?

A black box warning is a notice on the packaging of a prescription drug that warns patients and prescribers that the drug has potentially dangerous side effects. This warning system is primarily used by the Food and Drug Administration (FDA), an American regulatory agency that oversees the safety of pharmaceuticals produced and sold in the United States. Other national regulatory agencies may use different systems to indicate that drugs are potentially dangerous.

When a drug receives a black box warning, it means that studies on the drug have suggested that it can have dangerous or even deadly side effects. These warnings are often added retrospectively as the result of information about a drug that has been uncovered in the course of routine usage. When healthcare professionals start reporting dangerous side effects for a prescription drug, the FDA may hold a review to decide whether or not the drug requires a warning on the label.

The “black box” in this term refers to the bold black border that is drawn around the warning. This border is designed to draw attention to the warning, and to offset it from other information that may be present in pharmaceutical packaging. Thanks to widespread public awareness of the implications of a black box warning, a black box on drug packaging serves as an alert that the drug is dangerous even before people read the text.

Black box warnings must typically be included on the packaging of the drug and in the printed inserts used to provide information about the drug to patients and prescribers. They are designed to alert patients to the potential dangerous of the drug, and they also alert pharmacists and other medical professionals. Patients who receive a drug with this type of warning may want to discuss it and its implications with a healthcare provider, as people should not take drugs with potentially deadly side effects without knowing what those side effects are and how to recognize them.

Some notable examples include the warnings on antidepressant drugs that indicate that these drugs can cause suicidal thoughts in teenagers and children, and the warning on the anticoagulant drug warfarin about the risk of bleeding to death while on the medication. As a general rule, drugs with very serious side effects are left on the market because their benefits are viewed as more valuable than their potential dangers, although a black box drug will sometimes be removed from the market after evaluation by the FDA.