The U.S. Food & Drug Administration (FDA) has asked five pharmaceutical companies to recall certain extended-release metformin products, after tests confirmed the tablets contained excessive levels of N-Nitrosodimethylamine, a probable human carcinogen.
So far, only one – Apotex Pharmaceuticals – has actually announced a metformin recall. The FDA has yet to identify any of the remaining companies.
Metformin is a first-line treatment for Type 2 diabetes.
The FDA began investigating contaminated metformin late last year, following recalls in Singapore. Although the agency’s own tests did find NDMA in metformin, the FDA said at the time that the levels were far below its recommended daily limit of 96 nanograms.
In April, however, the online pharmacy Valisure reported that its own testing program had detected excessive levels of NDMA in 16 of 38 metformin samples tested. The highest levels were found in Amneal Pharmaceutical’s metformin, which in some cases contained as much as 16-times the FDA’s recommended daily limits. Several companies’ metformin contained more than 10 times the limit.
The FDA announced its latest findings late last week.
“Now that we have identified some metformin products that do not meet our standards, we’re taking action,” said Patrizia Cavazzoni, MD, acting director of the FDA Center for Drug Evaluation and Research, in a press release. As we have been doing since this impurity was first identified, we will communicate as new scientific information becomes available and will take further action, if appropriate.”
The FDA has recommended that consumer continue taking metformin, even if their medication is recalled, until they receive a replacement prescription from their doctor. Health care professionals should continue to prescribe metformin when clinically appropriate.
So far, FDA testing has not detected NDMA in immediate release metformin products (the most commonly prescribed type).
Apotex Pharmaceuticals announced its metformin recall late last Friday.
The action includes all lots of Metformin Hydrochloride Extended-Release Tablets, USP, 500 mgs, in 100-count bottles. According to the recall notice, the affected products bear NDC Code 60505-0260-1.
Apotex apparently stopped selling these tablets in February 2019, and only limited product remains on the market. So far, the company has not received any reports of adverse events related to use of the recalled metformin tablets.
Consumers with questions regarding the Apotex metformin recall can reach the company at 1-800-706-5575 (8:30am – 5:00pm, EST Monday thru Friday) or via email at UScustomerservice@Apotex.com. Consumers should contact their physician or healthcare provider if they have experienced any problems that may be related the use of contaminated metformin.
NDMA is classified as a probable human carcinogen based on animal tests that suggest exposure to high levels may increase the risk for cancer, including kidney, liver, gastrointestinal, and breast cancer.
The FDA began testing drugs for the chemical shortly after NDMA turned up in generic versions of valsartan and other “sartan” blood pressure medications, resulting in dozens of recalls.
Last fall, the agency began investigating the presence of NDMA in brand-name and generic versions of Zantac. The agency ultimately requested that all versions of the heartburn medication be removed from the market entirely, after confirming that the amount of NDMA in Zantac can increase over time.