Five US pharmaceutical companies have been told to recall their versions of a type of diabetes medication after tests found worrying levels of a chemical linked to cancer.
Several batches of metformin, which is widely used to reduce excess blood sugar in type 2 diabetes patients, tested positive for unsafe levels of N-Nitrosodimethylamine, the Food and Drug Administration (FDA) said on Thursday.
The FDA advised that patients should continue to take metformin until a replacement can be prescribed, acknowledging the risks of discontinuing the medication for patients.
Apotex Corp has recalled its supplies of the drug this week after the FDA found one of its lots to be contaminated.
The company said in a statement that it recalled all supplies of extended-release metformin “out of an abundance of caution”, and that it stopped selling the drug in the US in Febuary 2019 and little is still on the market.
The four other companies that have been requested to recall the product were not named in the FDA announcement.
The health and safety agency noted that immediate-release metformin had not been found to be contaminated.
Regulators have said that a number of other companies make versions of the drugs that don’t appear to be similarly affected.
The FDA increased testing after the same chemical was found in dozens of shipments of heartburn drugs last year.
As a result, a similar recall was ordered for over the counter and prescription heartburn medications such as Zantac.
Regulators are still assessing whether the recalls will lead to shortages of metformin across the country, where more than 34 million people in the US live with type 2 diabetes.
Additional reporting by The Associated Press