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Metformin is a drug used by people with diabetes. Getty Images
  • The FDA is working to determine whether metformin in the U.S. market is contaminated with a potential carcinogen.
  • Metformin is a prescription drug that helps control high blood sugar in people with type 2 diabetes.
  • NDMA is a contaminant commonly found in water and foods. People are regularly exposed to it in relatively low amounts, which isn’t harmful to human health, according to the FDA.

The Food and Drug Administration (FDA) announced it’s currently testing the widely used diabetes drug metformin for a cancer-causing contaminant known as N-nitrosodimethylamine (NDMA).

Certain metformin drugs in other countries were reported to contain low levels of the chemical, but the amount is within the naturally occurring range sometimes seen in food and water.

The FDA is working to determine whether metformin in the U.S. market may be contaminated with the potential carcinogen.

The announcement follows the massive recall of angiotensin II receptor blockers (ARBs) used for blood pressure and ranitidine drugs — commonly known under the brand name Zantac and used for heartburn — that took place earlier this year due to concerning levels of NDMA.

Metformin is a prescription drug that helps control high blood sugar in people with type 2 diabetes.

At this time, there are no other alternatives that work in exactly the same way, according to the FDA’s statement, so health officials recommend sticking with metformin until more information is available.

The brand name versions of metformin include Glucophage, Glucophage XR, Fortamet, and Glumetza.

“It could be dangerous for patients with this serious condition to stop taking their metformin without first talking to their health care professional. The FDA recommends prescribers continue to use metformin when clinically appropriate, as the FDA investigation is still ongoing, and there are no alternative medications that treat this condition in the same way,” the FDA wrote in a statement issued last week.

If the metformin drugs end up being recalled, the FDA will issue another update to patients and healthcare providers.

NDMA is a contaminant commonly found in water and food. People are regularly exposed to it in relatively low amounts, which isn’t harmful to human health, according to the FDA.

NDMA is a yellow, odorless liquid once used to make rocket fuel, but after high levels of the substance were found in the air, soil, and water samples near the manufacturing plants, NDMA use stopped.

Now it mostly appears when it’s unintentionally produced from chemical reactions at industrial sites. It can’t survive long in the environment because sunlight quickly breaks it down.

There are a few ways NDMA can find its way into drugs. It may contaminate the products during the manufacturing process or through how the drugs are stored or packed.

Low levels of NDMA aren’t dangerous. But if at least 96 nanograms are ingested daily, it becomes a health concern.

Over time it could increase a person’s cancer risk. Overexposure can also lead to jaundice, fever, vomiting, abdominal cramps, and dizziness.

“NDMA in high amounts and with long-term exposure is thought to be carcinogenic, and some animal studies have shown possible liver toxicity, but with high dose exposure and over longer periods of time,” Marilyn Tan, MD, chief of the Stanford Endocrine Clinic in California, told Healthline.

If the FDA were to determine that metformin batches in the U.S. market contained unacceptable levels of NDMA, the organization would advise the drug manufacturers to issue a recall, just as it did with blood pressure medications earlier this year.

“There’s no need to panic. The FDA has learned a lot from the contamination of the ARB blood pressure medication family and has refined their research and monitoring techniques to screen for NDMA levels,” said Guy L. Mintz, MD, director of cardiovascular health and lipidology at Northwell Health’s Sandra Atlas Bass Heart Hospital.

The FDA will be vigilant, monitoring the situation closely throughout the investigation, he adds.

“With any medication, you always have to consider risks versus benefits. Currently, there are no recalls for metformin in the United States,” Tan said.

“Suddenly stopping metformin, which is a commonly used and fairly effective diabetes medication, can lead to worsened diabetes control, which may do more harm than good,” she cautioned.

If you’re concerned, Tan recommends talking to your doctor to see if there are any alternative medications you may be able to take.

Stopping these medications too quickly could present serious, life threatening side effects.

Because the drugs haven’t been recalled, there’s no need to stop taking them as of now.

The FDA announced it’s currently testing the widely used diabetes drug metformin for NDMA, a cancer-causing contaminant.

The announcement follows the massive recall of blood pressure and heartburn drugs that took place earlier this year due to concerning levels of NDMA.

At this time, the FDA hasn’t recalled the metformin drugs. People with diabetes who take the medication are advised to continue doing so until more information is available.