Promethazine (Phenergan) is an irritant that can result in profound tissue damage and possible amputation if not administered properly. The purpose of this article is to discuss the safe parenteral administration of Phenergan.
Promethazine is a widely-used medication in healthcare facilities because it has multiple uses. It contains antiemetic (anti-nausea), sedative, antihistamine, and anti-motion sickness properties and can be administered orally, rectally, intravenously, or via deep intramuscular injection. Subcutaneous injection and intra-arterial infusion are not indicated.
The drug is also a known vesicant which is highly caustic to the intima of blood vessels and surrounding tissue (ISMP, 2006). Injectable promethazine is rather acidic and can lead to tissue injury if the clinician does not take specific precautions. In recent years, many patients have been awarded multimillion dollar settlements due to injuries that were the result of improper administration of promethazine. Some of these people have had fingers and parts of their arms amputated.
Severe tissue damage can occur regardless of the route of parenteral administration, although intravenous and inadvertent intra-arterial or subcutaneous administration results in more significant complications, including: burning, erythema, pain, swelling, severe spasm of vessels, thrombophlebitis, venous thrombosis, phlebitis, nerve damage, paralysis, abscess, tissue necrosis, and gangrene (ISMP, 2006).
The U.S. Food and Drug Administration is now requiring a boxed warning for all injectable promethazine products. The boxed warning will remind practitioners that due to the risks of intravenous injection, the preferred route of administration is deep intramuscular injection and that subcutaneous injection is contraindicated (FDA, 2009).
To reduce the risks, always dilute any promethazine that you plan to administer intravenously. Many facilities no longer allow this medication to be given via slow IV push, and the few places that still do permit it have policies requiring that 25mg per mL of promethazine be diluted with 10 milliliters of normal saline. If intravenous administration of promethazine is required, the maximum recommended concentration is 25 mg per mL and the maximum recommended rate of administration is 25 mg per minute through the tubing of an intravenous infusion set known to be functioning properly (FDA, 2009).
Stop any injections or infusions of this medication if your patient suddenly starts complaining of pain or burning. Furthermore, the administration of promethazine through a peripheral IV site on the hand or wrist is not recommended. Be on the lookout for the signs and symptoms of tissue damage including swelling, redness, discoloration, and pain at the injection site. Never give the 50mg/mL promethazine intravenously, because this strength is intended for deep intramuscular injection only.
With safe practice, pharmacological knowledge, and extra vigilance, you will be equipped to prevent or minimize any risks to your patients who receive parenteral promethazine.