The makers of promethazine must include a boxed warning on its label regarding a risk of gangrene and other tissue injuries that can occur if it is administered incorrectly, the Food & Drug Administration (FDA) announced today.
Promthazine, which has been on the market since 1956, was once sold under the brand name Phenergan by Wyeth, but that formulation has been discontinued. Various firms now market generic versions of the drug. Promethazine is approved for a variety of uses including allergic reactions, sedation, motion sickness, nausea, and vomiting associated with anesthesia and surgery, and as an adjunct to analgesics for control of postoperative pain.
According to an alert issued to health care providers, the labeling revision is based on the FDA’s analysis of post-marketing reports of severe tissue injury, including gangrene, requiring amputation. Numerous other cases of injection reactions such as injection site pain, redness, phlebitis, cyanosis, swelling, blistering, necrosis, and nerve damage were also found during its review, the FDA said. Current prescribing information for the drug contains information about the risk of tissue injury, possibly including gangrene, if the drug is inadvertently administered in the artery, but that information was not highlighted in a boxed warning.
The new boxed warning will state that promethazine should not be administered into an artery or under the skin because of the risk of severe tissue injury, including gangrene. There is also a risk that the drug can leach out from the vein during intravenous administration and cause serious damage to the surrounding tissue. As a result of these risks, the preferred route of administration is injecting the drug deep into the muscle.
A requested revision in the Dosage and Administration section of the label states that if health care professionals choose to administer promethazine intravenously, they should limit the drug’s concentration and rate of administration and ensure a properly functioning intravenous line.
The companies that make promethazine are required to submit the requested safety label changes to the FDA within 30 days or provide a reason why they do not believe such changes are necessary. If they do not submit new language, or the FDA disagrees with the language proposed by the companies, the agency can order the label change as deemed appropriate to address the new safety information.