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New Testing Finds Dangerous Levels of NDMA Contamination In Metformin

The online pharmacy Valisure recently announced that it found dangerously high levels of the probable human carcinogen N-nitrosodimethylamine (NDMA) in certain batches of the popular type-2 diabetes drug, Metformin. Valisure tested 38 batches of Metformin produced by a range of manufacturers and found levels of NDMA over the Food and Drug Administration’s (FDA) daily acceptable intake limit of 96 nanograms in 16 of these batches. Some of the NDMA levels were found to be over 10 times the daily acceptable limit!

On May 27, 2020, the FDA announced that it had also found high levels of NDMA in certain batches of Metformin and would be contacting the manufacturers of the contaminated medications to take appropriate action.

Valisure’s FDA Citizen Petition

Since this discovery, Valisure filed a Citizen Petition with the FDA and requested that the agency recall the contaminated batches of Metformin. In addition, Valisure implored the FDA to re-examine and modify testing methods to reduce the risk of underestimating NDMA levels.

Within the Citizen Petition, Valisure highlighted how they followed the FDA’s recommended testing protocols, but had also made some revisions to improve the accuracy of the tests.

Previous Valisure investigations and notifications to the FDA about NDMA contamination in the blood pressure medication Valsartan and the popular heartburn medication Zantac contributed to extensive recalls in the United States.

Background Information on Metformin and the FDA

On December 5, 2019, the FDA announced its investigation into the possibility of carcinogen contamination in Metformin. The statement came just one day after Singapore’s national health agency issued a recall of three Metformin medications due to NDMA contamination. Following the statement from Singapore, multiple global health agencies, such as Health Canada and the European Medicine Agency, announced similar investigations.

Just two months later, the FDA announced that it had found trace levels of NDMA contamination in Metformin. However, the FDA claimed that those levels did not exceed the acceptable daily intake limit of 96 nanograms.

New testing in May 2020 found levels of NDMA above the acceptable intake limit. It is possible Metformin recalls may be the agency’s next step in assessing the safety of the medication.

Valisure’s Testing Methods

The FDA used the Liquid Chromatography-High Resolution Mass Spectrometry (LC-HRMS) Method for determining the presence of NDMA in Metformin and published the details of their method on February 4, 2020. The method, which was developed and validated by the FDA, was used to determine the quantity of NDMA present in Metformin.

The method accomplishes its purpose by separating the NDMA impurity from Metformin by reverse phase chromatography (the process of separating hydrophobic moieties and those that do not have a dominant polar character) which is then detected by a high-mass accuracy (HRAM) mass spectrometer.

Quantitation is then performed by comparing the peak area of the NDMA impurity in the extracted ion chromatogram of the samples to the peak area of the NDMA reference standard using external calibration.

Valisure used the testing principle of the FDA’s method but also made modifications to achieve a lower limit of detection (LOD), which allows the tests to be alerted to lower levels of NDMA present in the samples. In addition, Valisure’s method allows for a lower limit of quantitation (LOQ) and a wider reportable range while using the same sample preparation method as the FDA.

As a result of the improvements, Valisure’s methods generates increased chromatographic resolution and sharper peaks demonstrating increased NDMA contamination in Metformin samples.

These optimizations allow Valisure’s testing methods to extract more detail about the amount of NDMA within Metformin samples. Without these improvements, Valisure claims the FDA’s method may have underestimated the NDMA concentration in the Metformin.

Risks of Metformin NDMA Contamination

Valisure’s findings reveal that the danger of NDMA contamination in Metformin may be even more severe than previously estimated by the FDA. The impact of this discovery is compounded by the fact that Metformin is one of the most prescribed drugs in the United States.

Metformin is sold under brand names: Glucophage, Glucophage XR, Fortamet, Riomet and Glumetza, in addition to being sold as a generic. There are dozens of manufacturers who produce and distribute Metformin products in the United States.

Exposure to NDMA beyond the daily acceptable intake limit has been linked to various cancers, such as:

  • Stomach cancer
  • Bladder cancer
  • Intestinal cancer (in both the large and small intestine)
  • Colon cancer / Colorectal cancer
  • Esophageal cancer
  • Liver cancer
  • Prostate cancer
  • Pancreatic cancer
  • Leukemia
  • Non-Hodgkin’s Lymphoma
  • Kidney cancer
  • Multiple Myeloma

How GoldenbergLaw Can Help You

If you or a loved one has been diagnosed with cancer after taking metformin, contact GoldenbergLaw for a free consultation on a metformin lawsuit today. Our Minnesota Cancer Attorneys have over 30 years of experience fighting pharmaceutical corporations and will deliver the Gold standard advocacy you deserve.


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