OTTAWA – Health Canada has conducted a safety review of gadolinium-based contrast agents (GBCAs) due to growing scientific evidence that gadolinium may accumulate in the brain following multiple contrast-enhanced magnetic resonance imaging (MRI) scans. Although no health consequences have been identified with gadolinium accumulation in the brain, Health Canada will be working with Canadian manufacturers to update the labelling of GBCAs to include this new information. Gadolinium is a chemical element and a component of dyes used to enhance contrast and improve radiology images. GBCAs are administered by injection and used for MRI scans when needed. After injection, gadolinium is eliminated through the kidneys (in urine) and for some of the agents also through the liver, but small amounts may stay in different parts of the body, including the brain. Gadolinium accumulation in the brain has been found in patients both with and without kidney disease. To date, Health Canada has not received any adverse event reports related to gadolinium accumulation in the brain. Patients and caregivers should talk to their health care professionals if they have questions about the use of GBCAs with MRIs for their individual health circumstances. Health professionals are advised to: limit the use of GBCAs to situations where the contrast agent is considered necessary, use the lowest effective dose, and assess the benefits and any potential risks to individual patients before administering repeated doses of GBCAs. Health Canada is also advising health care professionals that the available scientific evidence suggests that gadolinium accumulation in the brain is higher with the use of linear agents than with the use of macrocyclic agents, but it has occurred with both types. The gadolinium-based contrast agents authorized for sale in Canada are (in alphabetical order): DOTAREM (gadoterate meglumine) - macrocyclic agent GADOVIST (gadobutrol) - macrocyclic agent MAGNEVIST (gadopentetate dimeglumine) - linear agent MultiHance (gadobenate dimeglumine) - linear agent OMNISCAN (gadodiamide) - linear agent OPTIMARK (gadoversetamide) - linear agent PRIMOVIST (gadoxetate disodium) - linear agent ProHance (gadoteridol) - macrocyclic agent Health Canada is continuing its monitoring and evaluation of the risk of gadolinium accumulation in the brain associated with the use of GBCAs and will inform Canadians again as required.
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