Medicated patch can cause burns during MRI, warns FDA

09 March 2009

The US Food and Drug Administration has warned that some skin medicated patches such as those used for stopping smoking and other pain relieving patches should not be worn while undergoing magnetic resonance imaging scans or MRIs due to the risk of burns.

Since some of the patches have aluminum, which can be overheated during an MRI scan by the machine's large magnet that can cause the aluminum to overheat and cause skin burns similar to sunburn.

The patches include both brand name and generic products and those purchased over the counter without a prescription.

The FDA issued the Public Health Advisory on transdermal drug patches after learning that a warning was missing on some patches that contain aluminum or other metals in their non-adhesive backing.

The backing is the portion of the patch not in direct contact with the skin. While not attracted to the magnetic field of the MRI, the metal can conduct electricity, generating heat which can cause burns. Users of the patches reported receiving skin burns at their patch site when wearing the patch during an MRI scan.

"The risk of using a metallic patch during an MRI has been well-established, but the FDA recently discovered that not all manufacturers include a safety warning with their patches," said Janet Woodcock, M.D, director of the FDA's Center for Drug Evaluation and Research. "Because the metal in these patches may not be visible and the product labelling may not disclose the presence of metal, patients should tell both their healthcare professional and their MRI facility that they wear a medicated adhesive patch."