Error Alert
Institute for Safe Medication Practices, Horsham, PA
Many health care professionals know that promethazine injection is a vesicant and is highly caustic to the intima of blood vessels and surrounding tissue. Parenteral administration can result in severe tissue damage, regardless of the route of administration. However, inadvertent intra-arterial injection associated with I.V. use has resulted in more significant complications, including burning pain, erythema, swelling, severe spasm of vessels, thrombophlebitis, venous thrombosis, phlebitis, nerve damage, paralysis, abscess, tissue necrosis, and gangrene. Despite this well-known problem, the Institute for Safe Medication Practices (ISMP) occasionally receives reports of promethazine injection tissue injuries with catastrophic consequences.
An emergency department patient with acute pancreatitis received 25 mg promethazine that was intended for I.V. administration but was inadvertently administered intra-arterially. The patient immediately experienced excruciating pain and redness from his fingertips to his shoulder. Then his fingers and arm turned dusky and blackish. After 48 hours, swelling appeared, and the patient was still experiencing severe pain. Gangrene began to develop, and the patient reported that he is facing possible amputation of the affected digits, at least to the first knuckle and possibly beyond.
Promethazine labeling acknowledges that the medication can cause severe chemical irritation and damage to tissue, regardless of the route of administration.
Although the labeling states the I.M. route is preferred, the medication is available in a 25 mg/mL strength intended for deep I.M. or I.V. use, while a 50 mg/mL strength is intended for deep I.M. use only. This can be confusing.
The labeling mentions that, due to the proximity of arteries and veins in the areas used for intravenous injection, extreme care should be exercised to avoid perivascular extravasation or accidental intra-arterial injection. However, as the present case indicates, it may not always be possible to prevent intra-arterial injection.
No proven management of unintentional intra-arterial injection or perivascular extravasation exists.
The ISMP Targeted Medication Safety Best Practices for Hospitals (TMSBP) recommends the removal of injectable promethazine from all areas of the organization, including the pharmacy, and the classification of it as a non-stocked, non-formulary medication.
Further, the TMSBP call for an automatic therapeutic substitution policy to convert all injectable promethazine orders to another antiemetic, and removal of injectable promethazine from all drug order screens, order sets, and protocols.
Although the product labeling notes the preferred I.M. route, the TMSBP recommend avoiding I.M. promethazine because it can also cause tissue damage or be accidentally injected intra-arterially.
Product labeling notes that aspiration of dark blood does not preclude intra-arterial needle placement because blood is discolored upon contact with promethazine.
Using a syringe with a rigid plunger or a small-bore needle might also obscure typical arterial backflow. Subcutaneous injection is contraindicated in the labeling.
It has been nearly 15 years since ISMP first recommended that FDA reexamine promethazine product labeling to consider eliminating the I.V. route of administration. At the time, ISMP also called for hospitals to consider removing promethazine injection from hospital formularies. ISMP repeats these recommendations today. Please take action now to prevent these harmful events. ■