Last month, the FDA issued a black box warning on the injectable form of promethazine hydrochloride. Promethazine hydrochloride, once sold under the now-discontinued brand name Phenergan, is available in generic formulations in the form of tablets, liquid, rectal suppository, intravenous injection and intramuscular injection. The black box warning cautions health care providers against administering the IV injection into an artery or under the skin because gangrene or other severe tissue injury can result. It also can leach out from the vein during IV administration, causing serious tissue damage.

Another anti-nausea medication is metoclopramide, known by the brand names Reglan and Metozolov. The drug can be administered by injection, or taken as a pill by mouth. Metoclopramide is also a treatment for gastrointestinal conditions such as gastroparesis and GERD. Earlier this year, an FDA black box warning was placed on metoclopramide after long-term use of the drug was linked to a serious and debilitating involuntary movement disorder known as Tardive Dyskinesia.

Tardive Dyskinesia is identified by involuntary head jerking, eye blinking, facial grimacing, pucker and pursing of the lips, lip smacking and tongue thrusting. It may also involve involuntary movements of the fingers and hands. There is no known cure for Tardive Dyskinesia, even after the medication has been discontinued.

SOURCE: Reglan Side Effects › Anti-nausea drugs carry black box warnings