A study of patients exposed to gadolinium contrast dyes at the Mayo Clinic has revealed that hemodialysis patients had a 77-fold higher risk of developing nephrogenic systemic fibrosis (NSF), while kidney transplant patients had a 69-fold higher risk of the disease. The NSF study was published in the October issue of the Archives of Dermatology.
NSF is a debilitating disease that leads to excessive formation of connective tissue in the skin and internal organs. It is characterized by high blood pressure, burning, itching, swelling and hardening of the skin. Other symptoms include red or dark patches on the skin; pain deep in the hip bones or ribs and muscle weakness. NSF can progress to the point of causing severe stiffness in joints, and it can lead to death.
Gadolinium contrast dyes are approved for use in MRI procedures, and are sometimes used off-label in MRA studies. These agents were first introduced in the 1980s, and there are currently five such dyes on the market. They are: Covidien’s OptiMARK; Prohance and Multihance, both by Bracco Diagnostics; Bayer Healthcareâ€™s Magnevist; and GE Healthcareâ€™s Omniscan.
It appears that NSF only develops in people with pre-existing kidney disease who are exposed to the gadolinium agents. In September 2007, the U.S. Food & Drug Administration (FDA) asked the manufacturers of all gadolinium contrast dyes to add a black box warning to the product labels about its association with NSF. The FDA also warned that patients with kidney disease should avoid gadolinium contrast agents, and that the lowest possible dosage should be administered to such patients if use of the dyes cannot be avoided.
The Mayo Clinic study involved 94,917 patients exposed to gadolinium agents at the Mayo Clinic between January 1, 1999 and December 31, 2006. Of that group, 3,779 patients were on hemodialysis, 1,694 patients had undergone a kidney transplant, and 717 patients had liver transplants. A total of 61 patients had a clinical diagnosis of NSF.
The study found that 1% of patients undergoing hemodialysis, and 0.8% of patients who have undergone kidney transplant were at risk of developing NSF. The risk for liver transplant patients was 0%.
The study authors advocated for the development of new guidelines for the administration of gadolinium agents.
We reported previously this week that the FDA is still looking into the association between gadolinium agents and NSF. On Wednesday, we reported that an FDA review had found that OptiMARK, Magnevist and Omniscan carried a higher risk of NSF than other gadolinium agents on the market. Though the agencyâ€™s drug safety unit said the risk associated with the gadolinium contrast dyes â€œdoes not compel removal of specific (imaging agents) from the U.S. marketâ€, it has recommended that the drug labels note the varying levels of risks with each product. An outside panel of experts will take up the issue in December.
Following the news from the FDA, Covidien announced it would be modifying the label on OptiMARK to contraindicate its use in patients with severe kidney impairment. Mallinckrodt Inc., a Covidien company, has submitted this label change to the FDA and says it is implementing the new label in the U.S. effective immediately. Covidien also will update its educational materials to help physicians make informed decisions regarding the appropriate use of OptiMARK.