More lots of metformin recalled


The drumbeat of U.S. recalls continues for various lots of extended-release metformin because of contamination with unacceptably high levels of a nitrosamine that pose a cancer risk.

On Dec. 28, 2021, Viona Pharmaceuticals voluntarily recalled 33 lots of metformin hydrochloride extended-release tablets, USP 750 mg to the retail level, as a precautionary measure, because of possible contamination with N-nitrosodimethylamine (NDMA).

Metformin is used as an adjunct to diet and exercise to improve blood glucose control in adults with type 2 diabetes mellitus. Patients who have received impacted lots of metformin are advised to continue taking their medication and contact their physician for advice regarding an alternative treatment

The product can be identified as white to off-white, capsule shaped, uncoated tablets, debossed with “Z,” “C” on one side and “20” on the other side, and come in bottles of 100 tablets, which have been distributed nationwide. The 33 batch numbers are listed in a company statement.

The affected product was manufactured by Cadila Healthcare, Ahmedabad, India, for U.S. distribution by Viona.

In its statement, Viona said: “NDMA is classified as a probable human carcinogen (a substance that could cause cancer) based on results from laboratory tests. NDMA is a known environmental contaminant and found in water and foods, including meats, dairy products, and vegetables.”

This recall is being conducted “with the knowledge of the U.S. Food and Drug Administration,” it added.

Consumers with questions regarding this recall can contact the recall processor Eversana Life Science Services by phone at 1-888-304-5022, option 1; Monday-Friday, 8:00 a.m.–7:00 p.m. CT. Customers with medical-related questions who wish to report an adverse event or quality issues about the products being recalled should contact Viona Pharmaceuticals by phone at 888-304-5011, Monday-Friday, 8:30 p.m.–5:30 p.m., EST.

Latest in a long line of metformin recalls

This is the second time in 2021 that Viona has voluntarily recalled extended-release metformin tablets, 750 mg, because of potential contamination with NDMA. It recalled two lots in June, as reported by this news organization.

And in January 2021, Nostrum Laboratories recalled another lot of metformin extended-release 750-mg tablets, following on from a prior recall in November 2020.

These recalls follows 258 distinct U.S. lot recalls tracked by the FDA during the past 2 years because of unacceptably high NDMA levels in lots of metformin hydrochloride extended-release tablets.

The FDA has issued several statements about NDMA contamination of metformin formulations over the past 2 years, including a review of the methods used to detect NDMA and a summary of the information the agency had collected on excessive levels of NDMA in metformin.

According to the FDA’s 2020 summary, the agency has not yet determined how or why high levels of NDMA turn up so often in multiple batches of metformin hydrochloride extended-release tablets. However, published research attributed the contamination to certain methods of manufacturing metformin tablets.

A version of this article first appeared on Medscape.com.

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