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Questions and Answers: NDMA impurities in metformin products

Answers to questions about NDMA impurities found in metformin and FDA’s actions to address the issue

Updates on NDMA in metformin

Important information about the NDMA impurity in metformin products

  • The U.S. Food and Drug Administration has recommended recalls of certain metformin products that may contain the impurity N-nitrosodimethylamine (NDMA) above the acceptable intake limit.
  • Patients taking recalled metformin should continue taking it until a doctor or pharmacist gives them a replacement or a different treatment option. It could be dangerous for patients with type 2 diabetes to stop taking their metformin without first talking to their health care professional.
  • The agency is also asking all manufacturers of extended release versions of metformin to evaluate their risk of excessive NDMA and to test at-risk product before each batch is released onto the U.S. market. If testing shows NDMA above the acceptable intake limit, the manufacturer must inform the agency and should not release the batch to the U.S. market.
  • FDA’s testing has shown elevated levels of NDMA in some extended release (ER) metformin formulation but not in the immediate release (IR) formulation or in the active pharmaceutical ingredient.
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