Background: Levetiracetam is a novel antiepileptic drug with a broad spectrum of efficacy in epilepsy. We have tested the antimanic properties of the drug as an add-on to haloperidol in an open trial.
Method: After giving informed written consent, 10 bipolar I acutely manic (DSM-IV) inpatients were investigated in an on-off-on study design. All patients were treated with 5 to 10 mg/day of haloperidol, depending on tolerability, throughout the investigation. Levetiracetam (up to 4000 mg/day) was added until day 14, then discontinued and reintroduced at day 21. The psychopathologic changes were assessed with the Young Mania Rating Scale (YMRS).
Results: After a mean decrease of the YMRS scores from 29.6 to 17.2 during the first "on" phase, manic symptoms worsened during the "off" period (YMRS score 20.9) and ameliorated again during the second "on" phase, with a decrease of the mean YMRS score to 14.7 at the end of the study. The mean dose of levetiracetam was 3125 mg/day. At day 14, only 2 (20%) of 10 patients were responders (defined as a decrease in YMRS scores of 50%) compared with 7 (70%) of 10 responders at the end of the study at day 28.
Conclusion: The results from this open on-off-on add-on study suggest that levetiracetam exhibited additional antimanic effects. Controlled studies are clearly required.