Dr. Chris Stewart-Patterson (biography, no disclosures)
A significant number on patients on daily opioid medications may not be safe to drive a motor vehicle and that particular clinical issue can be problematic to assess within a primary care clinic visit.
The reported past-year use of opioid pain relievers by Canadians was 21% in 2010 . European traffic medicine research shows approximately 1% of driver stopped on roads and voluntarily submitting fluid test salivary tested are positive for opioid medication . Opioid medications may cause side effects of sedation, reduced attention, reduced short term memory reduced reaction time, reduced coordination, blurred vision and miosis all of which can adversely affect driving capability. A Canadian study notes that individuals on high doses of opioids (100-199 morphine equivalents) have an Odds Ratio of 1.42 for road trauma as compared with very low opioid doses .
What I did before
I largely relied on the self-report of my chronic pain patients. A 2006 study however notes “chronic non-malignant pain patients rated their subjective driving quality to be normal, although their road driving testing ratings and degree of alertness were significantly lower than those of the healthy controls.”  I would also use a Folstein mini-mental status examination or a Montreal Cognitive Assessment (MoCA) but these screening instruments may not be sensitive enough to detect cognitive impairment that could adversely affect driving .
What changed my practice
I found that there was some guidance in the literature. I consulted multiple guidelines [5, 6, 7, 8] concerning either prescribing long term opioids or medical driving guidelines. In addition, one review article was highly informative and advised that individuals on long term opioid medications and having any of the following four co-conditions may not be able to safely drive .
- Co-prescriptions or other substance use that may exert significant CNS effects
- High levels of pain (Greater than or = to 7/10 Visual Analogue Scale)
- Sleep disorder or daytime somnolence
- Significant depression, anxiety or other psychiatric diagnosis
What I do now
As per Canadian guidelines[xi] during dosage titration in a trial of opioid therapy, I advise the patient to avoid driving a motor vehicle until a stable dosage is established and it is certain the opioid does not cause sedation and when also when taking opioids with alcohol, benzodiazepines, or other sedating drugs.
I reassess the patients when they have achieved a stable opioid medication state  which is defined as
- The total daily dose is fixed for at least two weeks
- Medication dosage frequency is scheduled and spread throughout the day
- AND/OR at least 70% of the prescribed opioid is controlled release
I now assess multiple risk factors extracted from the above guides and have made a checklist for systematic clinical review that can be used in a primary care office visit.
The “Eight Ss”:
- Side effects of opioid medications: Potential impairing side effects affecting driving
- Substance Use Disorder: Risk of abuse of opioid medication
- Sleep disorder or disruption: Potential cognitive impairment in addition to any opioid side effects
- Sedating medications: Potential cognitive impairment in addition to any opioid side effects
- Severe pain: This degree of pain can be distracting in and of itself
- Sad or suicidal (Depression): Potential cognitive impairment in addition to any opioid side effects. Also at risk for suicide and substance misuse.
- Sight at night: Opioid induced miosis may adversely affect glare recovery for night driving.
- “Smashes”: If prior motor vehicle accidents occurred while on opioid medications that could an indication of impairment
Any of the above factors could be a relative or absolute contraindication for driving a vehicle while on opioid medication depending on the degree of impairment associated with the factor. Likely the more risk factors present the higher the risk of unsafe driving.
Under section 230 of the Motor Vehicle Act of British Columbia, medical practitioners must report to the Office of the Superintendent of Motor Vehicles (OSMV) if:
- a patient has a medical condition that makes it dangerous to the patient, or to the public, for the patient to drive a motor vehicle, and
- continues to drive after the medical practitioner warns the patient of the danger.
In British Columbia, further assessment may be indicated by the OSMV including use of the SIMARD, or a DriveABLE Assessment .
Canadian Medical Association guidelines inform us that physicians should be aware that legislation protects the physician from legal action brought against them for making a report. Some provinces however specify that the physician must have acted in good faith in order to benefit from this protection. There however could be problems if an MD does not make a report when potentially indicated.
“Physicians should be aware that there have been cases in which people injured in a motor vehicle crash have brought actions against physicians, alleging that the crash was caused in part by the medical disability of their patient, who should not have been allowed to continue driving. Physicians have been found liable for failing to report, notably in those provinces and territories with mandatory requirements.”
- UBC CPD online module: Can My Patient Safely Drive on Long-Term Opioid Medication? Up to 0.75 Mainpro-M1 or MOC Section 1 credits. For a more in depth review on opioids and driving see http://elearning.ubccpd.ca
- Screen for the Identification of Cognitively Impaired Medically At-Risk Drivers, A Modification of the DemTect http://www.mard.ualberta.ca/SIMARDMD.aspx
- DriveABLE Inc. http://www.driveable.com
- Bishop, C. (2013). National Advisory Council on Prescription Drug Misuse (Canada), Canadian Centre on Substance Abuse, Canadian Public Policy Collection, & Canadian Health Research Collection. First do no harm: responding to Canada’s prescription drug crisis (View)
- Simonsen, K. et al., (2012). Presence of psychoactive substances in oral fluid from randomly selected drivers in Denmark, Forensic Science International, 221, 33–38. (View with CPSBC or UBC)
- Gomes, T. et al., (2013). Opioid dose and risk of road trauma in Canada: A population-based study. JAMA Internal Medicine, 173(3), 196-201. (View)
- Veldhuijzen et al., (2006). Effect of chronic nonmalignant pain on highway driving performance. Pain, 122(1-2):28–35. (View) (View with CPSBC or UBC)
- British Columbia Medical Association. (2010). 2010 BC guide in determining fitness to drive p 46 (View)
- CMA’s Determining Medical Fitness To Operate a Motor Vehicle 8th Ed (2012) (View on CMA)
- National Opioid Use Guideline Group (NOUGG) & Canadian Public Policy Collection (2010). Canadian Guideline for Safe and Effective Use of Opioids for Chronic Non-Cancer Pain. April 30, 2010 (View)
- Chou, R. et al., (2009). Clinical guidelines for the use of chronic opioid therapy in chronic noncancer pain. Journal of Pain, 10(2), 113-130 (View) (View with CPSBC)
- Mailis-Gagnon, A. et al., (2012). Systematic review of the quality and generalizability of studies on the effects of opioids on driving and cognitive/psychomotor performance. The Clinical Journal of Pain, 28(6), 542-555. (View) (View with CPSBC or UBC)