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High-dose formulations of narcotic painkilling opioid drugs, such as oxycodone, fentanyl and morphine, can increase the risk of dependence, accidental overdose and death.Graeme Roy/The Canadian Press

The rate of high-dose opioid prescribing in Canada has shot up dramatically in the past six years despite guidelines advising against it, suggesting that the country's prescription drug problem is still out of control.

A new study published Friday in Canadian Family Physician reveals that each year, more than 30 million opioid pills or transdermal patches are dispensed in Canada – nearly one for every person living in the country. And the numbers are on the rise: In 2011, there were 961 high-dose opioid pills or patches dispensed for every 1,000 people, up from 781 per 1,000 in 2006.

"These are very, very high rates," said Tara Gomes, lead author of the study and scientist at the Li Ka Shing Knowledge Institute of St. Michael's Hospital in Toronto.

The findings are significant because high-dose formulations of narcotic painkilling opioid drugs, such as oxycodone, fentanyl and morphine, can increase the risk of dependence, accidental overdose and death. Canadian guidelines published in 2010 advise doctors that high-dose opioids are inappropriate for most patients.

"I think people can definitely argue there is a place for these drugs in the management of acute pain conditions and sometimes high doses of these products are needed," Ms. Gomes said. "However, the pervasiveness of the high-dose formulations across the country suggests these are being used outside of those indications where they're really warranted."

Canadians consume more opioids per capita than any other country except the United States. In July, Ms. Gomes published research showing that opioids now account for one out of every eight deaths of people 25 to 34 in Ontario.

Health Minister Rona Ambrose, under increasing pressure to tackle the growing problem of opioid addiction, said Friday the federal government understands the seriousness of the problem.

In August, Health Canada announced it will require opioid manufacturers to put stronger warning labels on the drugs. The government is also considering a requirement that all opioid drugs be tamper-resistant, making them harder to chew, snort or inject.

The latest study found Alberta and Ontario have the country's highest overall rates for high-dose opioid prescribing, at 1,133 and 1,382 doses for every 1,000 people, respectively. Newfoundland and Labrador saw the biggest increase in high-dose opioid prescribing over the study period, jumping nearly 85 per cent from 2006 to 2011. In Saskatchewan, the increase was 54 per cent.

Doctors often prescribe opioids to patients with chronic pain. As time goes on, many doctors give their patients higher doses, which helps some manage their pain, but also increases the risk of long-term dependence. A high dose of opioids is defined as 200 milligrams or more of morphine or equivalent; because opioid drugs all have different strengths, guidelines refer to morphine as a baseline measure for simplicity.

Opioids can also depress the respiratory system and, if an individual takes too much, he or she can stop breathing and die.

Despite data showing high-dose opioid prescribing is on the rise, Ms. Ambrose said Friday she believes prescribers are starting to show more caution when it comes to these drugs. However, she acknowledges that opioids continue to be overprescribed and that more work must be done to address the issue.

Opioid researchers, including Ms. Gomes, don't believe Health Canada's latest actions go far enough. Tamper resistance measures target those who abuse opioids recreationally to get high – but many people dependent on the drugs get them legitimately through doctors to treat pain.

What's needed, experts say, is a broad strategy to address the high rates of opioid prescribing and solutions to help people in chronic pain while not exposing them to the problem of dependence and addiction.

"We need to start looking more closely at how these drugs have been prescribed in terms of the doses they've been prescribed at," Ms. Gomes said. "Are we escalating doses in patients too quickly? Are we becoming nonchalant when prescribing very high doses of these products?"

With a report from Kelly Grant.