Medications & Driving

Medications can sometimes affect our ability to drive safely.

We also tend to take more medications to treat temporary or chronic medical conditions as we age. According to Statistics Canada, seniors are prescribed from two to five times as many drugs as the average Canadian. Not only does the risk of side-effects and interaction increase with the amount of drugs taken, but also, as we age, our bodies react differently, and it can take longer for the body to break down or get rid of a drug.

Open medication bottle with pills on a table

What You Need To Know:

  • Potentially dangerous side effects can be caused by commonly prescribed drugs, such as tranquilizers, sleeping pills or even over-the-counter drugs such as antihistamines.
  • Some of the medication side-effects that can affect our driving ability include drowsiness, dizziness, blurred vision, difficulty concentrating and staying awake, confusion, and memory lapses.
  • Talk to a pharmacist or doctor about the effects a new prescription or over-the-counter drug can have on driving.
  • As a precaution, read the warning labels on medications.
  • Take steps to ensure no one drives while under the influence of drugs or alcohol. Remember that driving under the influence of drugs or alcohol can be a criminal offence.

The Canadian Medical Association lists numerous drugs and how they can affect our ability to drive in its Driver’s Guide. Their descriptions of some more commonly prescribed or utilized drugs are as follows:

Sedatives and hypnotics
Individuals taking mild sedatives or short-acting hypnotics (sleeping pills) who experience no drowsiness (other than predictable sleep enhancement) can usually drive any type of motor vehicle without difficulty. However, use of benzodiazepines is a risk factor for unsafe driving among elderly people. Patients who are more heavily sedated for therapeutic reasons should not drive. Concomitant use of alcohol in these situations raises the risk of impairment.

Non-prescription antihistamines, motion-sickness medications and muscle relaxants
Drowsiness and dizziness are frequent – and unpredictable – side effects of older antihistamines, motion-sickness medications and muscle relaxants. The newer “non-drowsy” antihistamines are considered safer, but they may have a depressant effect on the central nervous system. Individuals using these drugs for the first time must be warned not to drive until it is determined whether they are prone to these side effects.

Antidepressants and antipsychotics
Individuals taking antidepressants or antipsychotics should be observed during the initial phase of dose adjustment and advised not to drive if they show any evidence of drowsiness or hypotension. Individuals who are stable and symptom-free on maintenance doses can usually drive any class of motor vehicle.

Anticholinergics frequently cause sedation and delirium (acute onset of cognitive deficits often associated with hallucinations and fluctuating levels of consciousness), especially in older people. Individuals (and their families) should be warned that people who experience these side effects should not drive. Examples of drugs with possible anticholinergic effects include antidepressants, antipsychotics, antihistamines and antipruritics, antiparkinsonian agents, antispasmotics, and antiemetics.

Association, CMA Driver’s Guide Determining Medical Fitness to Operate Motor Vehicles, 8th Ed, Section 6, Ottawa: Canadian Medical Association, 2012, modified and used with the permission of CMA; recognition to Dr. Hajela. CMA does not assume any responsibility for liability arising from any error in or omission from the use of any information contained in these sections. Permission to photocopy this section should be sought from Access Copyright, One Yonge St, Suite 800, Toronto, ON M5E 1E5, T: (416) 868-1620, E: [email protected].