Are patients who take stable dosages of opioids safe to drive?
Opioids for chronic pain
Ten years ago I made recommendations regarding opioid use and driving in an editorial comment in the journal Acta Anaesthesiologica Scandinavica.1 These recommendations are still valid. The key message is that a stable dose of opioid analgesics does not reduce cognitive abilities or vigilance. Therefore, the opioid treatment itself does not prevent the patient from driving a car. Patients taking opioids, without large fluctuations in size or timing of dose, are usually able to drive a car safely.2–6 However, severe pain attacks that are unrelieved will distract the driving patient enough to cause a risk to both the patient and others.
When a patient takes benzodiazepine anxiolytics, or any type of hypnotic, in addition to opioids, driving becomes unsafe.4 The same is of course true for even small amounts of alcohol in addition to an opioid analgesic drug.4
Gabapentin or pregabalin are often prescribed for neuropathic pain.7 Gabapentinoids are mildly sedative,7 therefore when added to a stable opioid regimen, the combination is likely to increase the risk of unsafe driving. Health authorities in some countries have published strict rules for driving when patients with chronic neuropathic pain need both a gabapentinoid and an opioid. These rules vary between countries and the physician responsible for evaluating driving ability has to follow the national rules.
In the UK there is now an initial roadside test to determine whether the driver has taken certain controlled drugs, including opioids.8 Threshold limits have been set for many of these drugs.8
Furthermore, as always the underlying illness itself may reduce cognitive and psychomotor skills.3
Opioids for acute or intermittent pain
It is important to realise that opioid-naïve patients who are given an opioid dose appropriate for treating acute pain, will usually have a period of reduced cognitive functioning and slowing of psychomotor skills.1 Depending on the dose, these effects may make the person incapable of driving a car safely. The same is true for patients taking opioids intermittently for pain attacks, and for people who take opioids for recreational purposes.1
Recommendations for doctors
The patient and their doctor must both make the decision as to whether the patient can continue to drive.1 The doctor should inform the patient in person and in writing about the known effects of opioids on driving ability and the regulations set by the authorities in their country. The patient should only consider driving after a considerable period (one to two weeks) on a stable opioid dose. The patient should never drive if he/she feels tired, sedated, fatigued, dizzy or sleepy. Should the patient experience these symptoms, they should always report them to their doctor to discuss the possibility of reducing the opioid dose. The patient must never combine opioid medication with alcohol, sedatives, anxiolytics, or any other psychoactive medication including illegal drugs. Ultimately, the patient must take the responsibility to only drive when he/she feels able and vigilant enough to drive safely.1
- Harald Breivik is emeritus professor of anaesthesiology, University of Oslo; consultant at the department of pain management and research, Oslo University Hospital, Oslo, Norway; and editor-in-chief, Scandinavian Journal of Pain