Is it Safe to Drive a Car when Treated with Anxiolytics? Evidence from onthe- Road Driving Studies During Normal Traffic

Background. The majority of those suffering from anxiety or related disorders are outpatients, and presumably involved in daily activities such as driving a car. However, anxiolytic drugs may possess sedative properties that reduce alertness and produce sleepiness. Therefore, it must be questioned whether it is safe to drive a car when treated with these drugs. Methods. A MEDLINE literature search (keywords driving and anxiety) and cross-references identified 14 placebo-controlled, double-blind studies that examined the effects of anxiolytic drugs on driving ability by conducting the on-the-road driving test during normal traffic. Primary parameter of the driving test is the Standard Deviation of Lateral Position (SDLP), the weaving of the car. Data from epidemiological studies was summarized as supportive evidence. Results. After single dose administration of benzodiazepines and related GABAergic compounds (diazepam, lorazepam, alprazolam, oxazepam, alpidem, suriclone, zolpidem) driving performance was significantly impaired. Further, although tolerance develops, driving studies show that the impairing effects of benzodiazepines and related GABAergic compounds may still be present after on week of daily treatment (demonstrated for diazepam, lorazepam, alpidem, suriclone). Driving performance was also significantly impaired after single dose administration of TCAs (imipramine, amitriptyline), but after repeated use of TCAs tolerance developed to the impairing effects on driving ability. In contrast, SSRIs (paroxetine, fluoxetine), venlafaxine, 5HT-antagonists (ritanserin, ondansetron) and buspirone produced no significant impairment on the driving test after both acute and repeated administration. These findings were in line with epidemiological evidence. Conclusions. Patients treated with benzodiazepines, GABAergic compounds, or TCAs should be cautioned when driving a car. Driving a car when treated with buspirone, venlafaxine, 5HT-antagonists, and SSRIs seems relatively safe.