Black Box Warning

In the United States, a boxed warning is a warning that death or serious injury may result from the use of a particular drug. It appears near the beginning of the package insert for certain prescription drugs and biologics, so called because the U.S. Food and Drug Administration specifies that it be concise and be formatted with a "box" or border around the text and a heading in all caps, containing "WARNING", to emphasize its importance. The FDA can require a pharmaceutical company to place a boxed warning. It is the strongest warning that the FDA requires, and signifies that medical studies indicate that the drug carries a significant risk of preventable, serious or even life-threatening adverse effects.