Opioids have side effects which can limit their acceptability to patients. They can slow reaction time, cause drowsiness, or cloud judgment when they are first started or increased.
Experts agree that driving or operating heavy machinery is unsafe and should be avoided until a stable dose has been reached.

Multiple studies suggest that many patients on chronic opioids (defined as no dose change within the last week) have minimal to no increased risk of motor vehicle collisions and no reduction in concentration or perception compared to controls - according to one study, those on chronic opioid therapy versus healthy controls displayed neither a difference in driving errors in community or obstacle course driving nor in tests of attention.

End result: patients should be encouraged to avoid driving until notified or else during opioid initiation or dose increases; those on a stable opioid dose for a week who experience no cognitive changes (drowsiness, difficulties in concentrating) probably are safe to drive.

For commercial driving, many individual states, employers, and insurance agencies generally prohibits opioid use, but with the warning that these rules “do not apply to the possession or use of a substance administered to a driver by or under the instructions of a licensed medical practitioner…who has advised the driver that the substance will not affect the driver's ability to safely operate a motor vehicle”

See reference for more information.

Adapted from Schisler RE, Groninger H and Rosielle DA. Counseling patients on side effects and driving when starting opioids. Palliative Care Network of Wisconsin. Fast facts and concepts #248. Internet. Accessed on May 20, 2019.