Health Canada needs to be more consistent with other countries when it comes to issuing warnings about the safety risks of certain medications, a University of British Columbia professor says.

Barbara Mintzes, the lead investigator of a new study published Monday, said that between 2007 and 2016, Health Canada issued safety warnings for only 50 per cent of drug-safety issues identified in the United States, Australia and the United Kingdom.

She joined researchers in analyzing 1,441 advisories over that period and found regulators in all four countries — which have similar demographics — were consistent in the decision to warn their populations over issues with the same medication just 10 per cent of the time.

Compared with the other countries, Health Canada issued advisories for only 317 of 635 drug-risk issues — just half of the issues identified by the U.S. Food and Drug Administration, the U.K. Medicines and Healthcare Products Regulatory Agency and Australia's Therapeutic Goods Administration, the study said.

The study, published by the American Medical Association's JAMA Internal Medicine journal, also involves researchers from York University in Toronto and the University of Sydney in Australia.

Health Canada issues warnings on its website, and Mintzes said it also sends letters to doctors who prescribe the drugs.

"Some of the safety warnings are put out by Health Canada, together with the manufacturer, and that will come as an individually sent letter to each doctor within a specialty or ... a broader set of all doctors who are practising in Canada," said Mintzes, an affiliate associate professor at UBC's School of Population and Public Health.

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Warning over statins

She said that in January 2013, Health Canada issued a warning about commonly prescribed cholesterol-lowering drugs, or statins, being linked to an increased risk of diabetes among patients already at risk for the disease.

However, the warning was issued a year after the U.S. and Australia informed patients about the drugs following large studies showing an association with diabetes, she said.

"Why did Health Canada wait another year after these warnings occurred in the U.S. and Australia?" asked Mintzes, who is also an associate professor at the University of Sydney.

Health Canada said it regularly liaises with key international counterparts, including in the U.S., Australia and the European Union, to determine if there are any emerging safety concerns. Once it becomes aware of any potential issues, an assessment is done to determine if a similar risk is warranted in Canada.

"Timing and content of risk communications can differ across jurisdictions for a number of reasons including, for example, how a product is used in Canada," the federal department said in a statement.

'We should have a legislated right to always having approved patient information provided to us every time we have a prescription dispensed,' said Barbara Mintzes, lead researcher of the study. (CBC)

Call for 'user-friendly' system

But Mintzes said Health Canada should be more transparent about the information on which it bases its warnings — especially because previously confidential clinical-trial data have been made publicly available for some time, following a similar stance in the E.U.

"We could do more as a country to have more services available to people who are using medicines, with a user-friendly website that provides information to the public so they can just look up their drug fairly easily," she said.

Pharmacies in Canada are also inconsistent in providing patients with written information about drugs and possible adverse reactions, Mintzes added.

"We should have a legislated right to always having approved patient information provided to us every time we have a prescription dispensed," she said.

A study in 2013 by the Canadian Institute for Health Information said up to a quarter of patients who visit emergency rooms due to adverse reactions to medication are admitted to hospital, and that seniors at greater risk for such effects.

Antibiotics are among the most common drugs associated with adverse reactions, which are associated with factors such as the number of drugs a patient is taking, the study said.