Oxcarbazepine as add-on treatment in patients with bipolar manic, mixed or depressive episode.

OBJECTIVES

The aim of this preliminary open-label trial was to evaluate the efficacy and safety of oxcarbazepine (OXC) as adjunctive therapy in 18 patients with bipolar disorder who did not respond satisfactorily to lithium.

METHODS

Eighteen patients with bipolar I (n=16) and bipolar II (n=2) disorder were treated openly with OXC for a 8-week period as add-on treatment to the existing lithium regimen. After the 8-week trial, all patients continued the treatment with OXC, and were followed-up prospectively. Outcome measures included the Clinical Global Impression-Bipolar Version Scale, the Bech-Rafaelsen Mania-Melancholia Scale and the Brief Psychiatric Rating Scale. These scales were administered at baseline and at the end of weeks 2, 4 and 8. Patients were subsequently assessed every 4 months for a period of time ranging from 4 to 12 months with the Longitudinal Interval Follow-up Evaluation.

RESULTS

The mean dose of OXC at the end of week 8 was 919.4 mg/day (SD+/-335.7). Eleven of the 18 patients were considered responders. The remaining seven patients were rated as nonresponders. Of the eleven responders to the 8-week trial, seven patients remained mood-stabilized for the entire period of follow-up.

CONCLUSIONS

OXC appeared to be significantly effective as add-on strategy in 60% of patients after 8 weeks of treatment. A substantial proportion (66.3%) of the 8-week trial responders maintained a satisfactory mood stabilization during the follow-up. Despite several limitations, our study suggests the potential usefulness of OXC as adjunctive therapy to lithium both in acute and long-term treatment of bipolar disorder.