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Canadian federal drug safety watchdog makes international headlines with statins research

A version of this commentary appeared in the Vancouver Sun, Calgary Herald and the Edmonton Journal.

Pharmacovigilance. It’s a fancy word, but means a very simple and important thing to all of us — it’s about keeping a watch (being vigilant) on the safety of the pharmaceutical supply. Researchers in this area try to find signals from large data sets, looking for adverse drug reactions which point toward better and safer ways of using drugs.

Ever since the Vioxx debacle of a decade ago, when one of the biggest selling drugs in the history of the world came crashing down after it was shown to cause heart attacks and deaths, there has been a huge demand for stronger levels of pharmacovigilance in this country.

Luckily, Canada’s federal government responded, too slowly and with too few dollars, but at least the creation of the Drug Safety and Effectiveness Network about five years ago was a start. Finally we had a home-based network of Canadian researchers doing solid pharmacovigilance research in this country, carrying out the kind of serious drug safety evaluation we desperately need.

For proof of concept, a DSEN study published this week in the British Medical Journal found that people taking higher strength statins (drugs to lower cholesterol, like Lipitor, Crestor or Zocor) face an increased risk of kidney injury. It found that patients on high potency statins were more likely to be hospitalized for acute kidney injury within 120 days of starting treatment compared to those taking low-potency statins.

This class of drugs has been under a dark cloud for a long time, especially due to the muscle-weakening, and cognitive effects that people in the “real world” (that is, outside the bounds of clinical trials) experience. That’s why real world research is so valuable — it can measure through large administrative data sets what kind of experiences people can have.

The absolute risk of kidney injury seemed small (about one in 275 high-dose statin patients were hospitalized for acute kidney injury, versus one in 375 for those on low-dose statins) but when you consider the millions of Canadians swallowing a statin every day, the overall number harmed is likely large.

This study again reminds us that taking a drug for one thing (lowering cholesterol) can have consequences of doing other, unexpected things (injuring your kidneys). Kidney damage can be profound and devastating, which is a high price to pay for someone who is otherwise perfectly healthy, but told by their doctor they need a drug to lower their cholesterol.

Over the years, real-world experiences of statins have started to seep into general practice, largely by those who report adverse drug reactions such as nagging muscle weakness and pain. Since about a third of statin users are taking higher potency statins, we now have some credible proof that more people are being harmed than need be.

The Canadian researchers who did this work looked at health records of two million patients in Canada, the United States, and the United Kingdom, essentially sifting through an enormous pile of anonymous patient data to find drug safety signals that would be impossible to do in smaller trials or epidemiological studies.

We can feel good that we’ve got strong federally funded pharmacovigilance studies in Canada producing results such as these. All, however is not rosy, especially when you consider how political drug safety evaluation work can be. And how threatening it can be to the pharmaceutical industry.

Alan Cassels is a pharmaceutical policy researcher at the University of Victoria and an expert advisor with EvidenceNetwork.ca

March 2013

This work is licensed under a Creative Commons Attribution 4.0 International License.