FDA investigates diabetes drug for contamination with cancer-causing agent

Same carcinogen found in Zantac and blood pressure medications may be in drug metformin

Add the popular diabetes drug metformin to the list of medications possibly contaminated with the carcinogen N-Nitrosodimethylamine, or NDMA.

This same carcinogen has led to recalls of blood pressure and heartburn medications.

Metformin is a prescription drug used to control high blood sugar in patients with Type 2 diabetes.

» Why have so many blood pressure medications been recalled?

"The FDA is investigating whether metformin in the U.S. market contains NDMA, and whether it is above the acceptable daily intake limit of 96 nanograms," said Janet Woodcock, director of the Center for Drug Evaluation and Research.

The Food and Drug Administration announced Wednesday it was aware metformin in other countries contained low levels of NDMA, but those levels were in the “naturally occurring in food and water” range.

NDMA is a common contaminant found in water and foods including cured and grilled meats, dairy products and vegetables. Everyone is exposed to some level of NDMA, Woodcock said.

The FDA recommends patients continue taking metformin to keep their diabetes under control because “there are no alternative medications that treat this condition in the same way.”

Since July 2018, the FDA has announced voluntary recalls of blood pressure and heart medications from Major Pharmaceuticals, Solco Healthcare, Teva Pharmaceuticals Industries, Mylan Pharmaceuticals and Prinston Pharmaceuticals over unacceptable levels on NDMA.

» Blood pressure medication recalls: Everything you should know, Atlanta doctors, experts say

» FDA alerts patients of additional ranitidine medication recall, also known as Zantac

In November, the FDA announced the recall of over-the-counter ranitidine tablets —also known as Zantac — prescription capsules and syrup because of unacceptable levels of NDMA.

The FDA investigation of metformin, Woodstock said, will “take into account the medical necessity of the drug, how many Americans may take it, and whether there may be alternative treatments available. The American public can expect that we will act quickly to address any issue as soon as we find out about it.”

If you have questions about the investigation, you can contact the FDA at 1-888-463-6332.