Metformin may contain nitrosamine impurity
The FDA is investigating whether metformin in the U.S. market contains N-nitrosodimethylamine. Low levels of the impurity have been found in the drug in other countries; however, there are no U.S. recalls at this time.
The FDA is investigating whether metformin in the U.S. market contains N-nitrosodimethylamine (NDMA), a probable carcinogen, the agency announced on Dec. 5. Over the past year and a half, some drugs, such as certain angiotensin II receptor blockers and ranitidine, have been recalled due to small amounts of the impurity.
Metformin in other countries was reported to have low levels of NDMA, although levels were within the range that naturally occurs in some foods and in water, the FDA said. The agency is testing for the impurity in samples of metformin sold in the U.S. but noted that there are no domestic metformin recalls at this time.