Gadolinium FDA information
FDA approved five gadolinium based contrast dyes used for enhancing the quality of MRI between 1988 and 2004. A combined pre- marketing study was done on all these five GBCAs, over a span of 3000 patients. The side effects ranged from most common mild allergic reactions to occasionally severe renal dysfunctions to even fatalities or deaths.
In December 2006, FDA started analyzing the reports of people who were administered gadolinium based contrast agents, to determine and identify symptoms of nephrogenic systemic fibrosis (NSF) and its related risk factors. It also asked all five FDA approved GBCAS’ manufacturers to add a black box warning to the labels of the medicine describing the risk of NSF.
The list of FDA approved GBCA is:
Other than the addition of the boxed warning, FDA also requested the makers of GBCAs to collect data of patients who have suffered from renal insufficiency after the administration of any of the contrast based drug. The purpose of doing this is to get a continual evaluation of new reports of NSF, and understand the magnitude of risk for NSF patients with kidney disease.
While some patients have suffered from rashes, hives etc, others developed irritation in the veins in which these dyes were administered causing irritation of blood vessels and skin and formation of blood clots. As gadolinium is mainly excreted through kidneys, people with existing kidney disorders or with impaired kidneys are known to suffer from toxic reactions.
Of all the five GBCAs- Magnevist, OmniScan and OptiMark are found to be inappropriate for use among patients suffering from acute kidney injury or chronic kidney disease. This was pointed out in the review carried out by FDA while checking the safety of most widely used GBCAs.
Director of the Division of Medical Imaging Products in FDA’s Centre for Drug Evaluation and Research, Rafel Rieves, MD explained that the FDA wants the labeling changes on the GBCAs to enhance the safe use of these dyes, including the avoidance of certain agents among patients at higher risk of NSF.
While FDA will continue to assess the safety of each GBCA (as the data suggests that NSF may follow due to the administration of any of the dyes), it has asked the healthcare professionals to keep a check on the below mentioned points before using any of the dye:
- Estimate kidney function through laboratory tests for patients already suffering from kidney disorders.
- People known to suffer from impaired drug elimination should not be advised to use GBCA, unless the imaging is essential and not available without contrast.
- GBCA should be administered only once during an imaging session.
- Patients suffering from renal dysfunction or impaired drug elimination, if have been given GBCA, then should be closely monitored for NSF, as they become high-risk patients for developing the same.
In GBCAs’ case, FDA is on a continual consideration of all the risk management options. It will evaluate any new reports of NSF and if required may request additional clinical studies and/ or labeling alterations.