Metformin, which is given to many people with type 2 diabetes to control high blood sugar, has been found to contain carcinogens in other countries, prompting official recalls in some parts of the world. The FDA has said that the drug will be recalled in the U.S. as well should it be found to be dangerous. In America, a daily intake greater than 96 nanograms is considered unsafe.
The carcinogen in question is N-Nitrosodimethylamine, or NDMA. It’s the same chemical that was found in heartburn and blood pressure medications in recent years, prompting full recalls of drugs like Zantac. Since then, the FDA has said that it will expand the testing requirements for these drugs to make sure their NDMA levels don’t exceed acceptable daily intake limits.
What is NDMA?
NDMA is a contaminant that can be found in water and certain foods. It can make its way into foods like cured meats and dairy products during packaging, processing and storage. While people are regularly exposed to low amounts of it, prolonged exposure can increase a person’s risk of cancer. Like glyphosate, the World Health Organization considers it a “probable human carcinogen.”
In addition, overexposure can cause fever, abdominal cramps, vomiting, dizziness and jaundice. Some animal studies have shown that higher doses could cause liver toxicity. The chemical was formerly used to produce liquid rocket fuel, softeners for copolymers, and additives for lubricants.
The FDA recently announced it is testing metformin to learn more about its NDMA content. The prescription drug, which is sold under brand names such as Glucophage, Glucophage XR, Glumetza, and Fortamet, is used by those with type 2 diabetes to help control blood sugar.
There has been speculation that the high NDMA levels in heartburn meds were the result of the drugs being heated above room temperature, perhaps during transportation from the manufacturing plant to the drugstore; a similar effect could occur when people keep their medication in their car on a hot day. The FDA said there are still some unanswered questions about the role of temperature in the formation of NDMA, but those who are taking metformin despite the potential contamination might consider keeping it out of the heat to be on the safe side.
Those still taking metformin should also keep in mind that people who take heartburn medications were advised to limit their intake of foods that contain nitrates, like processed meats, as there could be a link between the formation of NDMA in the body and the presence of nitrites while taking drugs like ranitidine or nizatidine.
Recall could be a blessing in disguise
More than 120 million people around the world have been prescribed metformin, which works by decreasing the amount of sugar the liver releases and improving the way the body responds to insulin.
Any recall might be a blessing in disguise for those taking the drug. It’s worth noting that metformin has the lowest rate of adherence of any major diabetes drug, due in large part to the toll it takes on people’s digestive systems. Many people give up within the first week or two because of gastrointestinal symptoms such as flatulence and diarrhea. Other side effects that can be seen with the drug include muscle pain, weakness, abdominal pain, B12 deficiency, and upper respiratory tract infections.
Many patients find that changing their diet can help keep their diabetes in check naturally and possibly lessen their dependence on risky prescriptions like the potentially carcinogenic metformin.
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