Carbamazepine but not pregabalin impairs eye control: A study on acute objective CNS side effects in healthy volunteers

SummaryPurposeThis prospective study compared the effects of the new antiepileptic drug (AED) pregabalin (PGB) with the established AED carbamazepine (CBZ) on eye movements and posture control.MethodsEye movements and posture control after AED intake were studied by electrooculography and posturography in 12 healthy volunteers who received single doses of 75 mg PGB and 400 mg slow release CBZ in a double-blind, cross-over, randomized trial.ResultsCBZ caused more slowing of the peak horizontal saccade (27%) than PGB (14%). For other parameters there was no statistically significant difference as compared to baseline and in the comparison of the two AEDs. CBZ and PGB, both impaired posture control but no statistically significant effect was found.DiscussionCBZ causes more commonly dizziness after intake than PGB, when given in single doses, which is reflected in objective measurements; CBZ but not PGB impaired saccadic eye movements. Electrooculography and posturography serve as an objective measure of AED CNS side effects and could be used at an early stage of drug development.