[FDA News Release, May 28, 2020] – The U.S. FDA has announced that several brands of metformin have tested positive for unsafe levels of the nitrosamine impurity, N-Nitrosodimethylamine (NDMA). NDMA is classified as a probable human carcinogen (a substance that could cause cancer) based on results from laboratory tests.
The agency has directed 5 companies to begin voluntary recall of the affected metformin extended-release (ER) formulations. The affected companies and metformin products are published on FDA’s website.
FDA is advising patients to continue taking metformin tablets even after recalls occur, until they consult with their health care professional who can prescribe a replacement. Patients with type 2 diabetes could face dangerous health risks if they stop taking their prescribed metformin.
Healthcare professionals should continue to prescribe metformin when clinically appropriate; FDA testing has not shown NDMA in immediate-release (IR) metformin products (the most commonly prescribed type of metformin). The agency is working with manufacturers of the recalled tablets to identify the source of the NDMA impurity. At this time, the elevated levels of NDMA have been found in some finished-dose tablets of the ER formulation but have not been detected NDMA in samples of the metformin active pharmaceutical ingredient.
Health Canada Important Safety Information, March 11, 2020
Earlier in Canada, certain lots of metformin have also been recalled due to the presence or possible presence of a nitrosamine impurity called N-Nitrosodimethylamine (NDMA) above the acceptable limit:
February 5, 2020 – Apotex Inc. recalled 8 lots of the diabetes medication APO-Metformin ER (extended release) 500 mg tablets
February 26, 2020 – Ranbaxy Pharmaceuticals Canada Inc. recalled six lots of its prescription RAN-Metformin drug from the Canadian market.
March 11, 2020 – JAMP Pharma Corporation voluntarily recalled all 26 lots of its prescription Metformin drug from the Canadian market (Metformin DIN 02380196 [500mg] and Metformin DIN 02380218 [850mg]) as a precautionary measure. NDMA test results are not available for this product; this recall has been initiated because of the potential presence of nitrosamine impurities in the finished product.
Details of the recalled metformin products are published on Health Canada website.