Opioids and Driving Don't Mix

Opioid prescriptions may increase the risk of car accidents among drivers

/ Author:  / Reviewed by: Chris Galloway, M.D.

(RxWiki News) Drinking and driving is an obvious no-no. But painkillers and driving can be just as dangerous. Let somebody else take over driving duties during pain management regimens.

A recent study in Canada looked at the rates of car accidents in relation to the dose of painkillers people were prescribed. The study’s results showed that the odds of a person on painkillers getting into a car accident increased as the dose of the painkiller increased.

"Don’t drive on painkillers."

Tara Gomes, MHSc, of the Ontario Drug Policy Research Network and epidemiologist with the Institute for Clinical Evaluative Sciences in Toronto, Canada, led a group of researchers to investigate the risk of car crashes involving painkillers, which often come in the form of opioids.

Prescription opioids can affect a person’s ability to drive a car by delaying reaction time and making it more difficult to think and pay attention.

Researchers looked through databases at adults between the ages of 18 and 64 that had received at least one publicly funded opioid prescription from 2003 to 2011 and had also been to the emergency room because of a car accident.

Ms. Gomes’ team found 5,300 eligible adults that were in road trauma as driver, passenger or pedestrian. The team then age and gender matched another 5,300 adults, who were not in car accidents, to act as a comparison group.

Researchers were looking for the dose of opioid in relation to car crash risk. Doses ranged from less than 20 mg to 200 mg or more per day of morphine or an equivalent dose of codeine, oxycodone, methadone or transdermal fentanyl patches.

Drivers on a low dose of morphine had 21 percent increased odds of getting into a car accident. Drivers on a moderate dose had 29 percent increased odds for getting into a car accident.

Drivers on a high dose had 42 percent increased odds for getting into a car accident. Patients on very high doses had 23 percent increased odds of getting into a car accident.

The drop from 42 percent down to 23 percent could be explained by those drivers having better judgment and choosing not to drive because they understood the risks of driving on very high doses of morphine.

People with morphine prescriptions were not more likely to get into car accidents or road trauma if they were passengers or pedestrians.

The study was limited by the population, which included only those who had publicly funded prescriptions. Another limitation was that researchers had no knowledge of how much of the opioid people were actually taking. Further studies should include greater diversity in socioeconomic backgrounds and knowledge of daily opioid intake, not just prescribed intake.

The authors recommended healthcare professionals prescribing opioids tell patients about the risks of driving under the influence of opioids. 

They concluded, “Among drivers prescribed opioids, a significant relationship exists between drug dose and risk of road trauma. This association is distinct and does not appear with passengers, pedestrians and others injured in road trauma.”

This study was published in January in JAMA Internal Medicine.

The study was funded by a grant from the Ontario Ministry of Health and Long-term Care, Drug Innovation Fund and the Institute for Clinical Evaluative Sciences. No conflicts of interest were reported.

Reviewed by: 
Review Date: 
January 18, 2013
Last Updated:
January 20, 2013