TORONTO — Pharmaceutical giant Apotex Inc. is voluntarily recalling a certain type of diabetes medication after one of the lots was found to have elevated levels of a contaminant linked to cancer.
On Saturday, Health Canada announced the recall was in effect for Apotex’s prescription metformin drug APO-METFORMIN ER (extended release) 500-milligram tablets.
The public health agency said the drugmaker’s test results showed that one lot (PY7174) contains a nitrosamine impurity called N-nitrosodimethylamine (NDMA) that “increased over time to a level above the acceptable limit.”
The advisory said Apotex was recalling eight other lots of the medication as a precautionary measure because the NDMA levels in those products “may increase over time.”
Health Canada has shared a list of the affected lots on its website.
Drugs containing metformin are widely used to treat people with Type 2 diabetes because they can reduce excess sugar in the blood.
In recent months, however, there has been growing concern over the safety of patients who ingest NDMA over the course of many years.
The organic compound is safe to consume in small doses over a lifetime, but it can be potentially carcinogenic if it’s taken in higher amounts.
Health Canada states that people are exposed to low levels of nitrosamines through a variety of foods, including smoked and cured meats, dairy products, and vegetables, as well as through drinking water, and air pollution.
“NDMA is not expected to cause harm when ingested at low levels,” the health agency said. “A person taking a drug that contains NDMA at or below the acceptable level every day for 70 years is not expected to have an increased risk of cancer.”
Apotex’s recall is the latest in a string of recent recalls for medications containing metformin.
In March, JAMP Pharma Corporation voluntarily recalled 26 lots of its metformin drug due to the “potential presence of nitrosamine impurities in the finished product.” And Ranbaxy Pharmaceuticals Canada Inc. recalled six lots of its prescription RAN-Metformin drug over NDMA levels in February.
Also in February, Health Canada issued a similar recall for eight lots of Apotex’s APO-Metformin ER tablets sold in 500-milligram tablets.
The public health agency advised patients who are taking one of the affected drugs to not stop taking it without first speaking to their health-care provider.
“The risks from not having adequate diabetes treatment outweigh any possible effects of exposure to the levels of nitrosamines found in the recalled Apotex metformin products,” the agency said in a statement.