Companies that produce metformin in America are being urged to “voluntarily recall” their products, it has been announced.
The US Food and Drug Administration (USFDA) has made the recommendation after lab tests found “above acceptable intake limit” of nitrosamine impurity N-Nitrosodimethylamine (NDMA) in some of the extended-release (ER) formulation of metformin.
NDMA has been an area of concern for some time as it is believed to be hepatotoxic, which means it can potentially damage the liver and is a known carcinogen in lab animals.
However, everyone is exposed to it at some level because it is a common contaminant found in water and foods including cured and grilled meats, dairy products and vegetables.
But it is the level of the NDMA, which can cause health problems and the FDA has said low levels are not harmful.
In a statement Dr Patrizia Cavazzoni, acting director of the FDA’s Center for Drug Evaluation and Research said: “The FDA has strict standards for safety, effectiveness and quality, and the agency makes every effort based on science and data to help keep the US drug supply safe.
“We understand that patients may have concerns about possible impurities in their medicines, and want to assure the public that we have been looking closely at this problem over many months in order to provide patients and health care professionals with clear and accurate answers.
“Now that we have identified some metformin products that do not meet our standards, we’re taking action. 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.”
People with type 2 diabetes who take metformin are being told they should continue taking their medication until they have consulted with their doctor who will be able to prescribe a replacement.
NDMA has not been found in immediate release (IR) metformin products, which is the most commonly prescribed type of metformin.
At the moment the regulator is trying to find the source of the NDMA impurity.