Accidental deaths due to opioid use in Ontario have soared over the past couple of decades, increasing dramatically after a new long-acting version of the drug oxycodone - sold as OxyContin - hit the market, a new study suggests.
Opioid-related deaths claim more people each year in Ontario than HIV, with 27 in a million people dying from an opioid-induced overdose versus 12 in a million to HIV, the researchers reported Monday in the Canadian Medical Association Journal.
Lead author Dr. Irfan Dhalla said there's been a suspicion among physicians that deaths due to prescription opioid use were on the rise, but this was the first effort to quantify it in Ontario. He admitted the effect was greater than he anticipated.
"When you think about the fact that there are far more people dying from prescription opioids than from HIV, that to me is surprising," said Dhalla, who practises general internal medicine at St. Michael's Hospital in Toronto.
A leading addictions researcher said the work underscores that the substantial increase in problems related to prescription opioid use is a "major public health challenge" for Canada.
Benedikt Fischer, interim director at the Centre for Applied Research in Mental Health and Addictions at Simon Fraser University, said the findings are especially important as Canada and the United States have the world's highest rates of medical opioid use.
"Thus, emphasis should be given to the questions of why these extensive increases in the use of prescription opioids ... have occurred, whether these compounds are necessary for the intended health outcomes and what may be done to reduce the use of prescription opioids to maximize pubic health without undue collateral damage," Fischer wrote in a commentary that accompanied the study in the journal.
Opioids are strong analgesics - a.k.a painkillers - which bind to receptors in the central nervous system, decreasing perception of pain and increasing pain tolerance. Though morphine and heroin are also members of this class of drugs, opioids used in pain control include codeine, oxycodone, and its slow-release cousin, OxyContin.
Dhalla and his colleagues examined trends in the prescribing of opioids in Ontario from 1991 to 2007 and went over coroners' reports of deaths in which opioid use was listed.
Over the period, all opioid-related deaths doubled, to 27.2 per million in 2004 from 13.7 per million in 1991. But after OxyContin hit the market in the mid-to-late 1990s, deaths involving that specific drug increased fivefold.
Over the period, opioids were implicated in 3,406 deaths. Most appeared to be accidental; coroners ruled the deaths were unintentional in 52.4 per cent of the cases and suicide was listed on only 23.6 per cent of death records.
The majority of the deaths involved other substances that also serve as a nervous system depressant, such as alcohol or sleeping pills.
Dhalla said opioids on their own can slow breathing to the point where a person slips into a coma; when combined with alcohol or sleeping pills, the risk is even greater.
"I think the saddest cases are probably where somebody has gotten into a friend's OxyContin or relative's OxyContin and just taken what appears to have been a very small amount just for kicks and then not woken up," he said.
"And we did see some of those cases."
He stressed, however, that the problem isn't simply about recreational or illegal use of the drugs - it's also about over-prescription of the drugs.
"I think there is a perception that this is a recreational drug use problem. And what our data have clearly shown is that most of the people who are dying are not outside the health-care system. They are seeing physicians frequently and they are more often than not receiving prescription opioids by prescription," he said.
December 7, 2009