High levels of a possible cancer-causing impurity were found in some Metformin lots

Some quantities of the drug Metformin, used in the treatment of diabetes, could have high levels of a possible cancer-causing impurity.

The probable carcinogen N-nitrosodimethylamine (NDMA) beyond acceptable limits was found in some versions of the medication produced by five pharmaceutical firms. NDMA is believed to be toxic to the liver and a possible factor in cancers of the stomach and bladder. The U.S. Food and Drug Administration (FDA) said on Thursday it has recommended them to recall the drug from the market. Only the Canadian company Apotex Corp was specified for the moment. In December, the FDA had started an investigation into metformin, which is used as an initial treatment for patients with type 2 diabetes.

Label of a recalled product

The agency said now patients should continue taking metformin tablets even after recalls occur until they consult with their health care professional who can prescribe a replacement. “There are additional manufacturers of the metformin ER formulation that supply a significant portion of the U.S. market, and their products are not being recalled. The FDA is continuing to work closely with manufacturers to ensure appropriate testing,” a statement said.