Immediately after the FDA said it found elevated levels of the carcinogenic ingredient N-nitrosodimethylamine (NDMA) in certain extended release (ER) metformin products, the first 2 major recalls are underway. Both Apotex Corp and Amneal Pharmaceuticals have issued a voluntary recall of its metformin hydrochloride extended-release tablets, according to the FDA.


Apotex Corp is voluntarily recalling all lots of metformin hydrochloride extended-release tablets, USP 500 mg, within expiry to retail level.

“Apotex was notified by the US Food and Drug Administration (US FDA) that one lot of Metformin Hydrochloride Extended-Release Tablets, USP was tested and showed results for N-Nitrosodimethylamine (NDMA) levels in excess of the Acceptable Daily Intake Limit (ADI) and recommended recall of the one tested lot,” Apotex said in a company announcement.

Out of an abundance of caution, the company is extending the recall to all lots of metformin hydrochloride extended-release tablets in the United States, Apotex added.

However, Apotex stopped selling this product in the United States in February 2019, and there remains only limited product on the market. To date, Apotex has not received any reports of adverse events related to use of that product, it said.

Amneal is voluntarily recalling all lots of metformin hydrochloride extended-release tablets, USP, 500 mg and 750 mg, within expiry to the retail levels. The affected products were distributed nationwide in the United States directly to wholesalers, distributors, retailers, and repackagers. Amneal is notifying its direct customers via mail by mailing a recall notification letter and is arranging for the return of all the recalled product. Anyone with an existing inventory of the product should quarantine the recalled lots immediately.

Months after FDA said it was investigating the carcinogenic ingredient NDMA in metformin products, the agency’s testing found elevated levels of NDMA in extended release (ER) metformin but not in the immediate release (IR) formulation, FDA said in a statement issued to Drug Topics®.

FDA has contacted a total of 5 manufacturers with ER metformin above the acceptable level and “will continue to take quick and appropriate action when needed to protect American consumers,” the agency said.

The FDA said that patients should not stop taking their prescription medications without first talking to their health care providers.

In early February, the agency posted the results of its laboratory analysis showing NDMA levels in some samples of the metformin products it tested. Overall, the levels of NDMA found in metformin ranged from “not detectable to low levels” at the time.

According to the agency, no sample of metformin that was tested by the FDA exceeded the acceptable daily intake of NDMA.

In December, regulatory agencies outside of the United States recalled some metformin drugs due to low levels of the impurity, prompting FDA officials to test samples of metformin sold within the United States