FDA Warns About NDMA Carcinogen Found in Metformin Diabetes Drugs, Requests Recalls

N-Nitrosodimethylamine (NDMA), the same carcinogenic substance that led to widespread recalls of Zantac, valsartan and other popular medications has been found in certain metformin extended-release products, according to the U.S. Food and Drug Administration (FDA). The agency issued a news release on May 28, 2020, alerting patients and healthcare providers to the presence of the nitrosamine impurity NDMA at levels above the FDA’s acceptable intake limit in several lots of extended-release metformin, a drug prescribed to control high blood sugar in patients with Type 2 diabetes. If you or someone you love has been diagnosed with stomach cancer, bladder cancer or another kind of cancer and you believe NDMA exposure from metformin to be the cause, contact an experienced drug injury attorney as soon as possible to discuss your options for legal recourse.

What is the Risk of NDMA Exposure?

NDMA is a probable human carcinogen, or a substance that could cause cancer, and the fact that the carcinogen has been found in several different medications has raised serious concerns about the possible risk of cancer among patients who use these medications long-term. Ever since the risk of NDMA exposure from pharmaceutical drugs was first brought to the public’s attention, patients taking recalled Zantac, valsartan and other NDMA-tainted drugs have been filing legal claims against the manufacturing companies, alleging that their exposure to NDMA caused them to develop various types of cancer, including bladder cancer, breast cancer, stomach cancer and testicular cancer. The FDA has previously found that the presence of NDMA in pharmaceutical drugs could be related to the drug’s manufacturing process, its chemical structure, or the conditions in which the drug is packaged or stored. Some medications can even convert to NDMA in the stomach during digestion.

FDA Investigating NDMA in U.S. Drug Supply

For nearly two years, the FDA has been investigating the presence of NDMA and other carcinogens in the U.S. drug supply and issuing widespread recalls of affected medications. The agency’s investigation began in the summer of 2018, with certain blood pressure and heart failure medications called angiotensin II receptor blockers (ARBs). These drugs, which include valsartan, losartan and irbesartan, were found to contain NDMA and other harmful nitrosamine impurities, such as N-Nitrosodiethylamine (NDEA) and N-Nitroso-N-methyl-4-aminobutyric acid (NMBA), and were recalled by the FDA. The FDA’s NDMA investigation was later expanded to include the widely used heartburn and acid reflux drugs ranitidine (Zantac) and nizatidine, and in April 2020, the FDA requested the removal of all ranitidine products from the market due to the risk of harm from NDMA.

FDA Warned About NDMA in Metformin

The latest stage in the ongoing investigation into the presence of NDMA and other cancer-causing nitrosamine impurities in pharmaceutical drugs involves extended-release versions of the widely used diabetes drug, metformin. It was in late 2019 that the FDA became aware of the presence of NDMA in some metformin drug products in other countries and began testing metformin products distributed in the United States to determine whether there was cause for concern. According to this latest news release, the FDA recently became aware of reports of higher than expected levels of NDMA in certain extended-release formulations of metformin tested by an independent laboratory. The FDA conducted its own testing and confirmed the finding of unacceptable NDMA levels in several lots of extended-release metformin, and the agency is now requesting that five manufacturers remove their metformin drugs from the market.

Metformin Manufacturers Required to Test Drug Products for NDMA

In addition to requesting the recall of affected metformin products, the FDA is asking all manufacturers of metformin-containing extended-release products to evaluate the risk of NDMA contamination in their drugs and test each batch before it is released into the U.S. market, in order to minimize the risk of side effects from NDMA contamination. “The FDA has strict standards for safety, effectiveness and quality, and the agency makes every effort based on science and data to help keep the U.S. drug supply safe,” said Dr. Patrizia Cavazzoni, acting director of the FDA’s Center for Drug Evaluation and Research, in the FDA’s news release. “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 health care professionals with clear and accurate answers. Now that we have identified some metformin products that do not meet our standards, we’re taking action.”