- The risk of cancer from taking NDMA contaminated products is low.
- Patients should continue taking metformin, even if affected by the recall, until they have a replacement or different treatment option from their doctor or pharmacist.
In late 2019, the Federal Drug Administration (FDA) announced that there had been findings of N-Nitrosodimethylamine (NDMA) in some metformin products sold in other countries. In early 2020, the FDA began an investigation into U.S. supply and identified only very low levels of NDMA, no products tested exceeded the acceptable level. A private laboratory’s testing resulted in findings of higher levels of NMDA in certain metformin extended release (ER) formulations. The FDA conducted its own testing and confirmed unacceptable levels of NMDA in some, but not all lots of metformin ER. The elevated levels have been detected in finished metformin ER tablets, but not in the active pharmaceutical ingredient.1
Carcinogens in medications sounds like a very concerning problem, and it certainly is. However, it is important to quantify that risk. Americans are exposed to small amounts of this substance in things that we consume every day such as water, smoked and processed meats, and fresh vegetables.2 Currently, we do not know how long patients have been exposed to higher levels of NMDA from metformin ER. What we do know is that the risk of diabetic complications from discontinuing metformin is greater than the relatively low risk of developing cancer due to taking this recalled product.1
Next Steps for Patients and Providers
Clearly communicating the risk to patients is key, but healthcare providers should also provide consistent instructions on what patients need to do next if they are on metformin ER. Currently, only select manufacturers of extended release products have been recalled. There are still many other suppliers that have not been asked to recall their products at this time. Currently, the FDA recommends that even if a patient has a recalled metformin product that they should continue taking as prescribed until a doctor or pharmacist gives them a replacement product or different treatment option.1
Staying Up-to-Date on Metformin Recalls
To stay up to date on which metformin products have been recalled, please refer to the FDA’s Drug Recall list which is updated regularly.
- FDA Alerts Patients and Health Care Professionals to Nitrosamine Impurity Findings in Certain Metformin Extended-Release Products. FDA. Published May 29, 2020. Accessed June 2, 2020. https://www.fda.gov/news-events/press-announcements/fda-alerts-patients-and-health-care-professionals-nitrosamine-impurity-findings-certain-metformin
- Dykstra J. Safe “-sartans.” Affinia Health Network. Published June 5, 2019. Accessed June 3, 2020. https://affiniahealth.com/pharmacy/safe-sartans/