Health Canada is looking into whether some metformin, a drug used to treat Type 2 diabetes, contains a cancer-causing impurity after other countries found problems with the drug.
“Health Canada is aware that some metformin products available outside Canada have been found to contain a nitrosamine impurity, N-nitrosodimethylamine (NDMA), above the acceptable limit,” the department stated in a press release Friday morning.
“At this time, Health Canada is not aware of any metformin products in Canada containing NDMA above acceptable levels. The Department has asked companies to test their metformin products and is collecting samples from companies to conduct its own testing.”
The U.S. Food and Drug Administration and the European Union’s drug watchdog are also examining metformin products after some drugs in Singapore were found to contain NDMA.
The European Medicines Agency described the risk so far as very low, urging patients to continue taking their medication because the danger of not adequately controlling diabetes is far higher — a caution echoed by Health Canada.
The FDA said it would recommend recalls as appropriate.
Metformin is a standard medication during the early stages of Type 2 diabetes. It helps control high blood sugar and is marketed under a number of brand names, including Fortamet and Glucophage.
NDMA is the same impurity behind a recall of the heartburn medication Zantac earlier this year.
Health Canada emphasized the risks of stopping diabetes medication in its statement and noted that it would take a long time for a person to notice the effects of NDMA.
“NDMA is classified as a probable human carcinogen,” the department wrote. “We are all exposed to low levels of nitrosamines through a variety of foods (such as smoked and cured meats, dairy products and vegetables), drinking water and air pollution. NDMA is not expected to cause harm when ingested at low levels.”
—With files from Reuters