Severe Tissue Injury with IV Promethazine
FDA Patient Safety News: Show #58, December 2006

The Institute for Safe Medication Practices recently warned that administering promethazine parenterally may cause more severe tissue injuries than previously recognized. Promethazine, which is commonly sold under the trade name Phenergan, has many uses including as an antihistamine, a sedative and an antiemetic.

ISMP points that out promethazine is a known vesicant which is highly caustic to the intima of blood vessels and surrounding tissue. Deep intramuscular injection into a large muscle is the preferred parenteral route of administration, and is least likely to cause damage. But promethazine is also given by slow IV push in many hospitals. The IV route, along with inadvertent intra-arterial or subcutaneous administration is most likely to result in significant complications, ranging from burning and pain to paralysis, tissue necrosis, and gangrene. Sometimes surgical intervention such as fasciotomy, skin graft or even amputation is needed.

ISMP describes several recent cases where severe tissue damage occurred following IV administration of promethazine. For example, in one case a 19-year-old woman who went to the emergency department with flu-like symptoms was given Phenergan IV. During the injection, she cried out in pain, and after the injection she told the nurse that her arm was still in significant pain and that she felt “something was wrong.” The nurse reassured her and then left the room. The patient’s arm and fingers became purple and blotchy and then over the next several weeks eventually turned black and shriveled. Her thumb, index finger, and top of her middle finger eventually had to be amputated.

ISMP points out that the product labeling makes several recommendations to reduce the risk of these adverse events. They include giving the drug in concentrations no greater than 25 mg/mL, administering the drug at a rate no greater than 25 mg/minute, injecting the drug through the tubing of an infusion set that’s running and known to be working satisfactorily, and stopping the injection immediately if the patient reports burning in order to investigate whether there might be intra-arterial placement or perivascular extravasation.

In addition to the manufacturer’s recommendations, ISMP lists about a dozen other strategies to prevent or minimize tissue damage when giving IV promethazine. Here are several suggestions.

• Stock promethazine only in the 25 mg/mL concentration (not the 50 mg/ml) since this is the highest concentration of promethazine that can be given IV.

• Consider 6.25 to 12.5 mg of promethazine as the starting IV dose, especially for elderly patients.

• Give the medication only through a large-bore vein and check the patency of the access site before administering.

• Administer IV promethazine through a running IV line at the port furthest from the patient’s vein.

• Consider administering IV promethazine over 10-15 minutes.

• Before administering the drug, tell patients to let you know immediately if burning or pain occurs during or after the injection.

Additional Information:

ISMP Medication Safety Alert! Serious Action needed to prevent serious tissue injury with IV Promethazine. August 10, 2006.
http://www.ismp.org/Newsletters/acutecare/articles/20060810.asp