WASHINGTON, Sept. 16 /PRNewswire-USNewswire/ -- The U.S. Food and Drug Administration is telling manufacturers of the drug promethazine to include a boxed warning regarding the injectable form of the drug. The warning, under FDA’s authority to require safety labeling changes, will highlight the risk of serious tissue injury when this drug is administered incorrectly. The agency is also alerting health care professionals to the new boxed warning for this product, which is used as a sedative and to treat nausea and vomiting.