[Opioids and driving ability]

Clinical observations of patients under oral opioid treatment suggest that the initially appearing central side effects such as sedation, dizziness or drowsiness decrease after a few weeks of treatment. However, it is still unclear whether long-term treatment with opioids impairs complex psychomotor functions such as driving a car.

Twenty patients on stable dosages of oral opioids were examined using a driving simulator. The patients were regular car drivers and not older than 70 years. Additionally, every patient had to complete a questionnaire for mental condition and vigilance and the "d II" letter cancellation task. Control groups tested in the same way were: patients before an elective operation after taking benzodiazepines for sedation, volunteers after alcohol consumption (0.80 per thousand ), physicians on call with less than 4 h of sleep and healthy volunteers without any medication.

Some of the patients treated with opioids reacted as fast as medication-free volunteers. There were no significant differences between the reaction times of older patients (>50 years) receiving opioids in comparison to the group of older healthy volunteers. The same result was obtained in the letter cancellation task. No differences could be seen between medication-free volunteers and patients receiving opioids with regard to tasks of visual or motor control skills. The volunteers under influence of alcohol and the patients under benzodiazepines had a considerable decrease in performance.

Long-term therapy with opioids does not inevitably impair complex skills, but the decision to permit driving a car can only be made in the individual case.

At the beginning of therapy with opioids the physician has to fulfil his duty to inform the patient of any possible dangers of treatment. From the medical point of view, driving must be prohibited until a stable opioid dosage is reached. Any changes in dosage (increase, reduction), change of the opioid and poor general condition independent of the opioid therapy must result in prohibition of car driving. Continuous control of the therapy with documentation is a duty of the physician. The written documentation should include the patients' physical and mental condition, side effects and the therapeutic result. From the medical point of view, driving can be possible when dosage treatment and general condition remain stable. In any case, the doctor has to remind the patient of the responsibility of critical self-examination. In doubt, special performance investigation should be taken into consideration.