Metformin Recall Urged Due To Presence of Cancer-Causing NDMA

An independent online pharmacy is calling for federal regulators to issue a metformin recall, indicating that the generic diabetes drug contains the same cancer-causing agent that has led to massive recalls for Zantac, valsartan and other medications in recent months.

In a citizen’s petition (PDF) filed with the FDA on March 2, Valisure reports that it has detected high levels of N-Nitrosodimethylamine (NDMA) in specific batches of metformin tested by the online pharmacy.

Given the cancer risk linked to NDMA, the petition calls for a recall to be issued for those batches of metformin, and for a widespread investigation of other versions of the widely used front-line treatment for type 2 diabetes.

The petition comes less than a month after the FDA declared that it had not found unacceptable levels of NDMA in metformin after conducting its own investigation.

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 indicated that NDMA was also discovered in some metformin samples sold outside the United States, raising concerns that metformin recalls may be necessary.

Metformin is sold under several brand names, including Glucophage, Carbophage, Fortamet, Diabex and Riomet. It is also often used in combination with other diabetes drugs, and is widely used worldwide.

Valisure indicates that it closely followed the FDA’s recommended testing procedures at a lab specifically accredited for analyzing levels of NDMA.

“Valisure’s analysis of 22 companies selling metformin and a total of 38 batches revealed 16 batches from 11 companies where NDMA levels were detected above the 96 ng daily acceptable intake limit, which was factored using a common number of tablets taken per day,” the petition states. “Several batches contained over 10 times the daily acceptable intake limit and there was significant variability from batch to batch, even within a single company; underscoring the importance of batch-level chemical analysis and the necessity of overall increased quality surveillance of medications.”

The company noted that the FDA’s own analysis did not find these levels of NDMA and suggested the agency needs to take a broader approach to its testing.

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 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.

Unlike valsartan, where NDMA contaminated the pill due to the manufacturing process, it appears that NDMA in Zantac was caused by the instability of the active pharmaceutical ingredient, which may produce NDMA when exposed to high temperatures, such as during transit or inside the human body. However it is not yet clear what processes are causing the levels of NDMA detected in metformin.

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.