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Even small doses of opioids increase risk of road crashes: study


Road trauma and prescription drug toxicity are two of the leading causes of accidental death in North America. In the first study of its kind to demonstrate a relationship between the dose of opioid analgesics and risk of road trauma, researchers at the Institute for Clinical Evaluative Sciences (ICES) found that even small doses of the powerful painkillers (a daily dose exceeding only 20 mg of morphine or equivalent) were associated with an increased risk of road trauma.

“Among drivers prescribed opioids, a significant relationship exists between the dose of opioid prescribed and risk of road trauma,” says Tara Gomes, lead author and scientist at ICES.

The study examined 549,878 patients aged 18 to 64 who received at least one publicaly-funded prescription for an opioid between April 1, 2003 to March 31, 2011 in Ontario and found that:

  • Among adult drivers prescribed opioids, a daily dose exceeding only 20 mg morphine (or equivalent) was associated with between a 21 per cent and 42 per cent increased risk of road trauma.
  • High opioid doses (between 100-199 mg of morphine or equivalent) were associated with a 42 per cent increased risk of road trauma relative to low doses.
  • This association does not appear to persist among passengers and pedestrians involved in road trauma.

“Injury and death resulting from motor vehicle collisions have significant public health and economic consequences. These findings could have important implications for clinicians when escalating patients to high opioid doses, and to policy makers tasked with educating the public on the potential risks of opioid medications,” says Gomes.

Authors: Tara Gomes, Donald Redelmeier, David Juurlink, Irfan Dhalla, Ximena Camacho and Muhammad Mamdani.

The study “Opioid dose and risk of trauma in Canada: a population-based study,” was published today in the Archives of Internal Medicine.

ICES is an independent, non-profit organization that uses population-based health information to produce knowledge on a broad range of healthcare issues. Our unbiased evidence provides measures of health system performance, a clearer understanding of the shifting healthcare needs of Ontarians, and a stimulus for discussion of practical solutions to optimize scarce resources. ICES knowledge is highly regarded in Canada and abroad, and is widely used by government, hospitals, planners, and practitioners to make decisions about care delivery and to develop policy.


Read the Journal Article