Canadian Manufacturing

Contaminants in generic drugs may cause long term harm to DNA: B.C. researcher

Health Canada said it is collaborating with six other international regulators including the U.S. Food and Drug Administration, the European Medicines Agency and Japan's Ministry of Health to better understand the global issue of nitrosamines.

June 16, 2021  The Canadian Press

Contaminants in some generic medications used to treat heart disease, diabetes and other common conditions could damage DNA, affect basic cell functions and increase the risk of cancer, suggests a study from the University of British Columbia.

Corey Nislow, a professor in the faculty of pharmaceutical sciences, said the findings from his lab on nitrosamines, impurities that are considered probable carcinogens, suggest overseas facilities that manufacture cheaper generic drugs in high volumes require strict regulation and enforcement to ensure they’re complying with standards.

Health Canada was among regulators in several countries that announced recalls in 2018 on medications containing the active ingredient Valsartan, which was found to contain a nitrosamine impurity before at least six other associated toxins were later detected in some other drugs made by different manufacturers.

Valsartan, sold under several trade names, is used to treat heart failure and high blood pressure.

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While Health Canada said there is no immediate health risk associated with the use of medications containing low levels of a nitrosamine impurity, Nislow said an estimated 50 million prescriptions were written for so-called sartans in Canada alone since nitrosamines were detected in many types of generics in 2012.

It’s not known if patients who took the drug for six years before the recalls could experience long-term effects, he said.

Health Canada said it is collaborating with six other international regulators including the U.S. Food and Drug Administration, the European Medicines Agency and Japan’s Ministry of Health to better understand the global issue of nitrosamines.

The agency said it sent a letter last December to drug manufacturers to conduct detailed evaluations of their manufacturing procedures for the potential presence of nitrosamines.

It said patients should talk to their health provider before stopping a prescribed medication and that not treating a condition may pose a greater risk than the potential exposure to a nitrosamine impurity.

Most of the inspections of facilities that make so-called active pharmaceutical ingredients are based on a self-reporting system, potentially putting consumers at risk, Nislow said.

Health Canada, the U.S. Food and Drug Administration and the European Medicines Agency are among regulators that have been testing drugs that are shipped from overseas.