Gadolinium-based contrast agents (GBCAs) used for MRI will now carry a warning regarding their potential retention in the bodies and brains of treated patients, according to the Food and Drug Administration.
The FDA is requiring the new class warning, along with other safety measures, based on evidence showing that trace amounts of gadolinium can be retained in the body for months to years after treatment.
Specifically, the agency will require that patients receiving GBCAs first receive a Medication Guide and that GBCA manufacturers conduct human and animal studies to further assess GBCA safety. At this time, the only known adverse health effect of gadolinium retention is nephrogenic systemic fibrosis, which affects a small subgroup of patients with pre-existing kidney failure. No causal association has been established between gadolinium retention and reported adverse events in those with normal kidney function.
The FDA recommended that health care professionals consider the retention characteristics of GBCAs for patients who may be at higher risk for retention, including those requiring multiple lifetime doses, pregnant women, children, and patients with inflammatory conditions, but stressed that, although repeated GBCA imaging studies should be minimized when possible, they should not be avoided or deferred when they are necessary. In the safety alert, the FDA noted that administration of the GBCAs Dotarem (gadoterate meglumine), Gadavist (gadobutrol), and ProHance (gadoteridol) produce the lowest gadolinium levels in the body, and the three agents leave similar gadolinium levels in the body.
The agency encourages reports of adverse events or side effects related to the use of GBCAs to its MedWatch Safety information and Adverse Event Reporting Program. Reports can be submitted online ator by calling 1-800-332-1088 to request a preaddressed form that can be mailed or faxed to 1-800-FDA-0178.