Some Generic Metformin Contains Nearly Double Daily Limit Of NDMA, Class Action Lawsuit Claims

A clas action lawsuit has been filed against a manufacturer of generic metformin, alleging that versions of the popular diabetes drug were distributed with nearly twice as much of a cancer-causing chemical than is allowed by federal safety regulations.

The complaint (PDF) was filed by Kristen Wineinger in the U.S. District Court for the District of New Jersey on March 9, pursuing damages on behalf of all users of generic metformin sold by Granules USA, Inc. and Granules Pharmaceuticals, Inc.

According to the lawsuit, recent tests revealed that Granules’ generic version of metformin contained levels of N-notrosodimethylamine (NDMA) that were 1.7 times higher than the FDA’s daily limit of 96 nanograms (ng).

NDMA is a chemical byproduct, which is considered a carcinogen. It used to result from making rocket fuel in the early 1900s, but today is only used in laboratory experiments to induce cancer in animal test subjects.

In recent months, detection of the chemical in other drugs has resulted in wide scale Zantac recalls and valsartan recalls, after it was confirmed that dangerously high levels of NDMA were present in the popular heartburn and blood pressure medications.

Late last year, reports first warned about the potential risk that problems may also be impacting metformin, after some versions of the drug sold outside the United States tested positive for NDMA, raising concerns that metformin recalls may be necessary. However, the FDA indicated that testing of products distributed in the U.S. found that the metformin NDMA contamination levels were undetectable or below federal limits for exposure to the chemical.

Earlier this month, the independent online pharmacy Valisure filed a citizen’s petition urging the FDA to issue metformin recalls, after independent testing found levels of NDMA in certain pills that was higher than the agency’s recommended daily exposure threshold of 96 nanograms.

Metformin is sold by a number of different generic drug makers, and also marketed under several brand names, including Glucophage, Carbophage, Fortamet, Diabex and Riomet. It is also often used in combination with other diabetes drugs.

Wineinger, of Indiana, indicates she used Granules’ version of metformin for some time before learning it was one of the products tested by Valisure, which found high levels of NDMA.

According to Valisure, each 500mg Metformin ER tablet sold by Granules contained about 41 ng of NDMA. Since the standard dose is four tablets daily, that adds up to about 164 ng per day of NDMA exposure, which is 1.7 times the amount recommended by the FDA.

“When purchasing metformin from Defendants, Ms. Wineinger reviewed the accompanying labels and disclosures, and understood them as representations and warranties by the manufacturer, distributor, and pharmacy that the medications were properly manufactured, free from defects, and safe for their intended use,” the lawsuit states. “Ms. Wineinger relied on these representations and warranties in deciding to purchase metformin from Defendants, and these representations and warranties were part of the basis of the bargain, in that she would not have purchased metformin from Defendants if she had known that they were not, in fact, properly manufactured and free from defects.”

A similar metformin class action lawsuit was filed just days earlier, on March 3, against a number of other manufacturers. To date, none of the drug makers have agreed to issue a recall of metformin, raising concerns among user and the medical community. However, health officials stress the importance that patients continue to take their prescribed diabetes treatment, unless otherwise directed by their doctor.

NDMA In Zantac and Valsartan

Valisure is the same pharmacy which first raised alarms about the link between Zantac and cancer in September 2019, after finding that some pills contained 3,000,000 ng of NDMA. This led to further FDA testing, which confirmed the high levels were present in virtually all Zantac products and their generic equivalents, resulting in a widespread, and still ongoing, Zantac recall.

Concerns over NDMA drug contamination in pharmaceutical drugs began to emerge in 2018, with an investigation into a number of generic blood pressure drugs that were found to contain high levels of the chemical. This led to several rounds of recalls for valsartan, losartan and irbesartan, and investigations suggested that NDMC may have contaminated the drugs as a by-product of changes in the generic drug manufacturing process.

In response to concerns about the cancer risk with valsartan and other similar drugs, and the possibility of shortages for the hypertension drugs, the FDA established a permissible daily limit for NDMA at 96 nanograms, requiring pills that may expose users to more of the carcinogen to be recalled.

While drug makers and federal regulators indicate they are continuing to investigate the underlying cause of both the NDMA contamination, many consumers diagnosed with cancer in recent years are now pursuing valsartan lawsuits and Zantac lawsuits, alleging they may have avoided a cancer diagnosis if other treatments had been used.