FDA Requires Stronger Warnings on Some MRI Contrast Agents

September 10, 2010, 1:00PM. By Heidi Turner

Washington, DCThe US Food and Drug Administration (FDA) announced it is requiring stronger warnings about the risk of severe MRI contrast agent side effects. The warnings affect MRI contrast agents that contain gadolinium.

The FDA announced on September 9, 2010 that gadolinium-based contrast agents would begin carry a warning on their labels "about the risk of a rare and potentially fatal condition known as nephrogenic systemic fibrosis (NSF), if the drug is administered to certain patients with kidney disease."

Magnevist, Omniscan and Optimark were singled out in the FDA's news release, which noted that the contrast agents would be described as inappropriate for patients with acute kidney injury or chronic severe kidney disease. Furthermore, the labels would include information about the need for patients to be screened for kidney dysfunction before using the gadolinium-based contrast agents.

"The FDA's review of the safety of the most widely used GBCAs [gadolinium-based contrast agents] determined that Magnevist, Omniscan, and Optimark are associated with a greater risk than other GBCAs for NSF in certain patients with kidney disease," the news release states. "Data suggest that NSF may follow the administration of any GBCA and the FDA continues to assess the safety of each GBCA to better estimate its NSF risks."

Nephrogenic systemic fibrosis is a potentially life-threatening condition in which excess connective tissue builds up in the skin. The patient's joints, eyes and internal organs can be affected by NSF. As the disease progresses, the patient's skin becomes harder and tighter, and patients may eventually become confined to a wheelchair.

A possible reason that kidney dysfunction is linked to nephrogenic systemic fibrosis is that gadolinium is excreted through the kidneys. Patients with kidney insufficiency would eliminate the gadolinium slowly, allowing more time for potential side effects to develop and putting those patients at higher risk of serious side effects.

The FDA recommends that health care professionals only use gadolinium-based contrast agents in patients with impaired kidney function if the MRI is essential and cannot be done without the contrast agent. Gadolinium-based contrast make the MRI scans easier to read.

"The FDA is requiring these labeling changes to enhance the safe use of gadolinium-based contrast agents, including avoidance of certain agents among patients at highest risk for nephrogenic systemic fibrosis," said Rafel (Dwaine) Rieves, M.D., director of the Division of Medical Imaging Products in the FDA's Center for Drug Evaluation and Research.