Rationale: Carbamazepine (CBZ) is known to produce cognitive side effects being at least partly relevant for driving. In contrast to this, the cognitive effects of oxcarbazepine (OXC) are suspected to be less pronounced.
Objective: This study aimed to test 900 mg/day OXC as compared to 600 mg/day CBZ with respect to driving.
Methods: Driving performance of 27 healthy volunteers under subchronic treatment of OXC and CBZ was assessed in a driving simulator with a double-blind, randomized, crossover design including a baseline measurement. The test course contained a representative set of scenarios. Lane-keeping performance, driving mistakes, and eyelid closure (as a behavioral measure of sleepiness) were analyzed. In addition, subjects were asked to assess their driving performance, effort, attention, and sleepiness subjectively.
Results: Both drugs had negative effects on driving as reflected in poorer lane-keeping performance, higher rate of driving mistakes, increased sleepiness, and worse subjective ratings. These effects were most obvious in monotonous situations and could be compensated in situations challenging to cognitive and motor driving skills. With respect to all considered parameters, CBZ did more often differ significantly from baseline than OXC.
Conclusions: Under both drugs, driving performance was worse than at baseline. Even though deterioration of driving performance was only slightly less pronounced under OXC than under CBZ, it might be recommended as more appropriate than CBZ for epileptic patients who need to drive a car.