Are Canadians in the dark about potential drug safety risks?

Government warnings about potential drug safety risks vary significantly across countries, according to a new international study coauthored by researchers at the University of British Columbia.

In a study published in JAMA Internal Medicine, researchers analyzed how often drug regulators in Canada, the US, the UK, and Australia issued safety advisories about the potential health risks of medications. After analyzing 1441 advisories over a 10-year period, covering 680 drug-safety concerns, researchers found that regulators in the four countries were only consistent in the decision to warn the public in their own country 10% of the time. Between 2007 and 2016, Health Canada issued safety warnings for only 50% of the drug safety issues identified by regulators in Australia, the US, and UK.

The study’s primary investigator, Barbara Mintzes, affiliate associate professor at UBC’s School of Population and Public Health and associate professor at the University of Sydney in Australia, finds it concerning that there is so little consistency between countries regarding how they communicated emerging health risks of medicines.

Before new medicines hit the market, each country’s regulator approves them for use often based on limited safety evidence collected during clinical development. However, once a drug enters general use, other safety issues can become apparent including rarer or longer-term effects—prompting regulators to issue safety advisories on how to avoid these risks. For example, in January 2013, Health Canada issued a warning that statins were associated with a “risk of increased blood sugar levels and a small increased risk of diabetes among patients already at risk for the disease.” Regulatory warnings about this risk appeared almost a year earlier in the US and Australia.

Adverse drug reactions are estimated to account for up to two-thirds of drug-related emergency department visits and hospital admissions, according to the Canadian Institute for Health Information. More information is available at www.med.ubc.ca/news/are-canadians-kept-in-the-dark-about-potential-drug-safety-risks.