Driving safety when you’re on medication

Medications help a lot, but some make driving risky. Drowsiness, slow reactions, blurred vision or dizziness can happen with prescription drugs and over-the-counter pills. You don’t need to stop important treatment — you just need to know which meds and what to watch for.

Common medication effects that impair driving

Here are the effects that matter most on the road and the types of drugs that cause them:

Drowsiness or sedation: antihistamines (especially older ones like hydroxyzine/Atarax), some antidepressants, antipsychotics, opioids, and some sleep aids. If a drug makes you sleepy while sitting, it will do the same while driving.

Slow thinking and poor coordination: benzodiazepines, muscle relaxants, and some anti-seizure medicines can slow your reactions and judgment.

Blurred vision or light sensitivity: eye drops, some antihistamines and migraine meds can affect how well you see signs and hazards.

Low blood pressure or dizziness: beta-blockers, certain blood pressure meds and some antidepressants can cause lightheadedness, especially when you stand up quickly.

Mixing with alcohol or other drugs: alcohol greatly increases impairment. Combining alcohol with sedating meds is a common and dangerous mix.

Practical steps to stay safe behind the wheel

Follow these simple, concrete steps every time you start a new drug or change a dose:

Read labels and ask: check the medicine leaflet for “may cause drowsiness” or “avoid driving.” If the label is unclear, ask your pharmacist: "Will this affect my driving?"

Test before driving: try the medication at home when you don’t need to drive for a day or two. Note how you feel at the times you’d normally drive — morning commute, after lunch, or at night.

Avoid alcohol and other sedatives: don’t drink when taking meds that cause drowsiness. Even small amounts of alcohol can make impairment worse.

Plan trips around dosing: if a drug peaks in effect two hours after a dose, avoid driving during that window. For long drives, take breaks every 90 minutes and switch drivers if possible.

Carry a list of medications: keep an updated list in your glove box and phone. It helps first responders and can avoid dangerous drug combinations if you get prescribed something new on the road.

Talk to your doctor about alternatives: if a needed drug makes driving unsafe, ask about other options with less impact on alertness. There are often choices that preserve safety.

Driving while impaired by medication can have legal and safety consequences. Check provincial rules if you’re in Canada and when in doubt, skip the drive and use a ride or public transit. A small pause now can prevent a serious accident later.