Cancer Risks for Metformin Users: Who’s Affected?

Diabetes medication being recalled for possible cancer-causing contamination.

The Food and Drug Administration has ordered several drug makers to recall Metformin, a prescription oral medication used to control high blood sugar in individuals with type-2 diabetes, due to a contaminant in the drug that has been linked to cancer.

According to the FDA, as of July 13, 2020, several batches of metformin made by different drug manufacturers tested positive for a potential carcinogen and are being recalled:

  • Granules Pharmaceuticals: 12 lots
  • Lupin Pharmaceuticals: All lots
  • Avkare (repackager for Amneal): All lots
  • Apotex: All lots
  • Amneal: All lots
  • Marksans (labeled as Time-Cap): One lot (XP9004)
  • Teva (labeled as Actavis): 14 lots
  • PD-Rx Pharmaceuticals (repackager for Amneal): All lots
  • PD-Rx Pharmaceuticals (repackager for Marksans): All lots
  • The Harvard Drug Group (repackager for Apotex): One lot (T-02134)
  • Preferred Pharmaceuticals (repackager for Marksans): Four lots (J0119M, K1419L, K2719J, A0220H)

Other recalls may be added to this list. The FDA has asked the drug makers to issue a voluntary metformin recall of the affected batches. There have been approximately 15 different recalls of Metformin from 2012 to 2020. 

Four of the drug makers have agreed to issue a voluntary metformin recall. However, a growing number of patients who take metformin for diabetes are concerned that the drug they were taking to regulate their blood sugar may have put them at an increased risk of cancer.

Some metformin users may consider taking legal action against the drug makers for releasing a potentially dangerous drug into the market.

A metformin lawsuit could allow those affected to seek compensation for the losses they suffered, such as medical expenses, lost wages, pain and suffering, emotional distress, and other damages related to the metformin cancer risk.

If you or someone you love has taken metformin—whether you have been diagnosed with cancer or not— you may have a legal claim.

Submit your information now to find out if you qualify to join a free diabetes drug metformin recall lawsuit investigation.

What is Metformin?

A tablet shows metformin's chemical breakdown

Metformin for Type-2 Diabetes

Metformin medication is used by patients with type 2 diabetes to reduce excess sugar in their blood. It works by reducing the amount of blood sugar the liver produces. It also helps improve the body’s response to insulin.

The diabetes drug, which is part of the biguanide class of diabetes drugs, is reportedly derived from natural compounds found in French lilac. These natural compounds were thought to be used in folk medicine to treat “sweetwater sickness.” Metformin medication is sold under several brand names, including Fortamet, Glucophage, Glucophage XR, Glumetza, and Riomet.

Metformin may be used alone or with other drugs to help control blood sugar levels. The metformin pill should be taken as directed by a physician. The diabetes medication is just one part of a treatment program that may include diet, exercise, and regular blood sugar tests.

The medication is also referred to as a lifestyle therapy option for those with type 2 diabetes by the American Association of Clinical Endocrine and American College of Endocrinology.

Although there are some adverse metformin side effects, metformin benefits generally outweigh the risks for patients with type 2 diabetes. Potential metformin adverse effects may include:

  • Lactic acidosis
  • Diarrhea
  • Nausea
  • Vomiting
  • Flatulence
  • Upset stomach
  • Weakness
  • Metallic taste in the mouth

Other Metformin Treatment Usages

In addition to treating type 2 diabetes, metformin is also used to treat women with polycystic ovarian syndrome. In some cases, metformin may increase fertility. Women with childbearing potential may want to discuss birth control options with their doctor while they are taking metformin.

Recalled Metformin Concerns

diabetes medication metformin under investigation

Can Metformin Cause Cancer?

Certain batches of the metformin diabetes drug have reportedly tested positive for unsafe levels of N-Nitrosodimethylamine (NDMA), a chemical that can form as a manufacturing byproduct.

NDMA was formerly used in the production of rocket fuel. It is classified as a probable human carcinogen.

Although there have not been any reports that metformin causes cancer, the FDA has told the makers of the affected diabetes drugs to recall the products due to NDMA contamination.

The NDMA contamination was reportedly only found in the extended-release versions of the diabetes drug. The FDA says that no contamination problems were found in immediate-release versions of metformin.

To date, there have been no reports of cancer associated with the contaminated batches of metformin. However, long-term exposure to NDMA may create an increased risk of various types of cancer.

The FDA urges patients to continue taking the metformin drugs until their doctor is able to prescribe a replacement medication.

There has been concern about the risk of bladder cancer associated with diabetes. Certain diabetes medications such as Actos, a diabetes medication manufactured by Takeda Pharmaceuticals, may increase the risk of bladder cancer. A study in the journal Diabetes Care found that patients taking metformin for diabetes did not see a reduction in the rate of bladder cancer.

Why Did the FDA Recall Metformin Medication?

On May 28, 2020, the U.S. Food and Drug Administration announced that several batches of the diabetes drug metformin tested positive for unsafe levels of N-Nitrosodimethylamine (NDMA), a chemical that has been linked to cancer. The chemical can form as a manufacturing byproduct. It is an environmental contaminant which can be found in water, meats, dairy products, and vegetables.

The FDA told five drug manufacturers to recall their versions of metformin because they contained NDMA levels in excess of the Acceptable Daily Intake Limit (ADI) of 96ng/day. The metformin recall only affects certain extended-release versions of the diabetes drug.

In response, four of the drug makers have agreed to a voluntary metformin recall of the affected batches of the diabetes drug.

Amneal Pharmaceuticals announced on May 29, 2020 that it was voluntarily recalling all lots of Metformin Hydrochloride Extended Release Tablets, USP, 500 mg and 750 mg after the FDA notified it that testing showed unacceptable levels of NDMA in seven lots of the medication.

The drugmaker notes that it has not received any reports of adverse metformin side effects associated with the recall. The company also says that it is conducting further scientific evaluations of the diabetes drug.

After the FDA found contamination in one lot of its extended-release metformin medication, Apotex Corp. voluntarily recalled all supplies of the drug “out of an abundance of caution,” the drugmaker said in their official statement. Apotex says it stopped selling metformin in the United States in February 2019 so there is currently not much of the diabetes drug left in the U.S. market.  The Apotex recall includes Metformin Hydrochloride Extended-Release Tablets, USP, 500mg.

Metformin medication sold under the Actavis and Time-Caps Labs Inc. brand names has also been recalled.

The metformin recall includes:

  • Actavis Metformin Hydrochloride Extended-Release Tablets, USP 500mg and 750mg (NDC numbers 62037-571-01, 62037-571-10, 62037-577-01, and 62037-571-10)
  • Amneal Metformin Hydrochloride Extended-Release Tablets, USP 500mg and 750mg (NDC numbers 53746-178-01, 53746-178-05, 53746-178-10, 53746-178-90, 53746-178-Bulk, 65162-178-09, 65162-178-10, 65162-178-11, and 65162-178-50 in the 500 mg dosages and NDC numbers of 53746-179-01, 53746-179-Bulk, and 65162-179-10 in the 750 mg dosages)
  • Apotex Corp. Metformin Hydrochloride Extended-Release Tablets, USP 500mg (NDC number 60505-0260-1)
  • Time-Caps Labs Inc. Metformin Hydrochloride Extended-Release Tablets, USP 500mg (Lot # XP9004)

The drug makers all note that they have not received reports of adverse metformin effects. The fifth metformin drugmaker affected by the FDA recall has not been announced.

Metformin is not the only drug to be affected by NDMA contamination. Last year, NDMA contamination caused several popular heart medications to be recalled.

Have Any Metformin Warnings Been Issued?

The FDA issued a metformin warning and recall request on May 28 regarding the potential cancer risk for certain batches of the metformin diabetes drug. The companies affected by the FDA recall request have indicated they will notify their distributors and customers who are affected by the metformin recall.

If you have a prescription for metformin, you should contact your health care provider for medical advice.

Until then, the FDA recommends that you continue taking the drug as directed because it can be dangerous to discontinue the drug without the direction of a medical professional. If you are not sure if your prescription drug is affected by the metformin recall, you can contact your pharmacy for more information.

Have Any Metformin Cancer Lawsuits Been Filed?

There have not been any metformin cancer lawsuits as of now. However, it is likely that the drugmakers will face future metformin lawsuits over allegations they failed to ensure the safety of their products and put patients at an increased risk of cancer.

Potential plaintiffs could argue that they would have chosen an alternative diabetes drug if they had known that there was a risk that metformin causes cancer due to the NDMA contamination.

A metformin lawsuit could seek compensation for the costs spent on the medication, past and future medical expenses, costs for medical monitoring, lost wages, pain and suffering, and other damages—whether metformin users have been diagnosed with cancer or not.

Should You File a Metformin Lawsuit?

If you have taken metformin, or are currently taking metformin, you may have a legal claim regardless of a cancer diagnosis.

By filing a metformin lawsuit or class action lawsuit, you can help to hold drug makers accountable for releasing potentially unsafe drugs on the market and potentially receive compensation for any injuries or losses you suffered.

Submit your information now to find out if you’re eligible to join a free metformin cancer class action lawsuit investigation. If you qualify, a lawyer will contact you for a free case evaluation.

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