GAITHERSBURG, MD. — Black box warnings added to the labels of all gadolinium-based MRI contrast agents have reduced the number of reported nephrogenic systemic fibrosis events to almost none in the last year, according to Dr. James Kaiser.
“The numbers of new events have tapered dramatically, probably due to public awareness of the association of NSF [nephrogenic systemic fibrosis] with GBCA [gadolinium-based contrast agent] administration,” he said at a joint meeting of the Food and Drug Administration's Cardiovascular and Renal Drugs and Drug Safety and Risk Management advisory committees. Event dates are either the date of administration of contrast or the date of diagnosis of NSF.
The FDA began receiving reports of NSF possibly being linked to gadolinium-based contrast agents in 2006 when 194 event dates were reported.
This “probably reflects awareness of the medical community of the potential connection between GBCA administration and NSF and changes in radiologic practice,” said Dr. Kaiser of the FDA's office of surveillance and epidemiology. There were 128 reported events in 2007, 55 in 2008, and 6 in 2009 (through September).
In 2007, the FDA asked manufacturers to include a boxed warning on the product labels of all gadolinium-based contrast agents.
Five gadolinium-based contrast agents have been approved for use in the United States: Magnevist (gadopentetate dimeglumine), Omniscan (gadodiamide), OptiMARK (gadoversetamide), MultiHance (gadobenate dimeglumine) and ProHance (gadoteridol).
As of September 2009, 382 reports of NSF had been associated with Omniscan (GE HealthCare), 195 with Magnevist (Bayer HealthCare), 35 with OptiMARK (Covidien), 1 with MultiHance (Bracco Diagnostics), and 0 with ProHance (Bracco Diagnostics).
The FDA asked the committees to consider whether warning labels should continue to be grouped together as a class or if there was adequate evidence to single out agents that increase NSF risk.
“The majority of the group feels that at least two of the agents appear to be different from the other agents,” said Dr. Robert A. Harrington, who chairs the Cardiovascular and Renal Drugs Advisory Committee. The majority recommended the use of Omniscan and OptiMARK be contraindicated in patients with severe kidney dysfunction. However, there was uncertainty as to how to define severe kidney dysfunction.
There was less consensus on whether a third agent, Magnevist, might also warrant contraindication language.