The NDMA contaminant has the potential to be carcinogenic if there is exposure to above acceptable levels over long term use. This recall does not apply to immediate release metformin products, and the agency recommends that clinicians continue to prescribe metformin when clinically appropriate.
The FDA is contacting 5 pharmaceutical firms in particular as posted on the agency’s website, and is recommending that the companies voluntarily recall these products one of which listed on the agency’s site is Apotex Corp and its metformin hydrochloride ER USP 500 mg tablets.
The FDA has become aware of NDMA in some metformin products in other countries which inspired them to test American supplies of metformin to determine the risk as part of an ongoing investigations into nitrosamine impurities across a variety of medication types, which includes recalls of hypertension and heartburn medications within the past 2 years.
“Now that we have identified some metformin products that do not meet our standards, we’re taking action. As we have been doing since this impurity was first identified, we will communicate as new scientific information becomes available and will take further action, if appropriate,” said Patrizia Cavazzoni, MD, acting director of the FDA Center for Drug Evaluation and Research, in a press release.
The agency states that it is working closely with manufacturers of the recalled products to identify the source of the NDMA impurity and to ensure that appropriate testing is carried out. There are other additional manufacturers that supply metformin ER products to the American market but they are not being asked to recall their products.
The FDA is working to determine if this recall of products from the 5 pharmaceutical firms of the ER form of this drug will result in any shortages, and if so the agency will be collaborating with manufacturers to prevent or reduce any impact of possible shortages.
“We understand that patients may have concerns about possible impurities in their medicines and want to assure the public that we have been looking closely at this problem over many months in order to provide patients and healthcare professionals with clear and accurate answers,” Cavazzoni said.