A link to the advisory is available at: www.fda.gov/medwatch/safety/2009/safety09.htm#Transdermal
To eliminate any risk of skin burns, transdermal medication patches should be removed before patients undergo magnetic resonance imaging scans, the Food and Drug Administration advises.
The FDA's public health advisory was prompted by fewer than half a dozen reports of burns associated with medication patches that contain trace amounts of aluminum or other metals, which can heat up just enough during an MRI scan to cause a burn.
The reported cases have been in nicotine patches, Dr. Sandra Kweder, deputy director of the FDA's Office of New Drugs, said during an FDA telebriefing.
About 60 medicated patches are on the market, and include both over-the-counter and prescription products. Uses include smoking cessation, contraception, hormone therapy, and pain treatment. More than 25% of patches contain metal, Dr. Kweder said. Even transparent patches may contain metals.
Clinicians should instruct the patient about when to remove the patch before the procedure and about replacing it after the procedure, the advisory said.
The FDA is currently reviewing the labeling and composition of all transdermal medication patches, and is working with manufacturers to improve labeling, which could include some type of warning on the patch.