First major review provides evidence of sharp increase in deaths from painkillers in US and Canada and leading causes

The number of deaths involving commonly prescribed painkillers is higher than the number of deaths by overdose from heroin and cocaine combined, according to researchers at McGill University. In a first-of-its-kind review of existing research, the McGill team has put the spotlight on a major public health problem: the dramatic increase in deaths due to prescribed painkillers, which were involved in more than 16,000 deaths in 2010 in the U.S. alone. Currently, the US and Canada rank #1 and #2 in per capita opioid consumption.

"Prescription painkiller overdoses have received a lot of attention in editorials and the popular press, but we wanted to find out what solid evidence is out there," says Nicholas King, of the Biomedical Ethics Unit in the Faculty of Medicine. In an effort to identify and summarize available evidence, King and his team conducted a systematic review of existing literature, comprehensively surveying the scientific literature and including only reports with quantitative evidence.

"We also wanted to find out why thousands of people in the U.S and Canada are dying from prescription painkillers every year, and why these rates have climbed steadily during the past two decades," says Nicholas King, of the Biomedical Ethics Unit in the Faculty of Medicine. "We found evidence for at least 17 different determinants of increasing opioid-related mortality, mainly, dramatically increased prescription and sales of opioids; increased use of strong, long-acting opioids like Oxycontin and methadone; combined use of opioids and other (licit and illicit) drugs and alcohol; and social and demographic factors."

"We found little evidence that Internet sales of pharmaceuticals and errors by doctors and patients--factors commonly cited in the media -- have played a significant role," Prof. King adds.

The findings point to a complicated "epidemic" in which physicians, users, the health care system, and the social environment all play a role, according to the researchers.

"Our work provides a reliable summary of the possible causes of the epidemic of opioid overdoses, which should be useful for clinicians and policy makers in North America in figuring out what further research needs to be done, and what strategies might or might not be useful in reducing future mortality," says King. "And as efforts are made to increase access to prescription opioids outside of North America, our findings might be useful in preventing other countries from following the same path as the U.S. and Canada."

The results of this research are published in the American Journal of Public Health, http://ajph. aphapublications. org/ doi/ abs/ 10. 2105/ AJPH. 2014. 301966

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