Background: Preliminary data from case reports and small open trials suggest a role for lamotrigine in the treatment of bipolar disorder, although controlled data for the manic phase are lacking.
Method: Thirty inpatients with a DSM-IV diagnosis of bipolar I disorder, currently manic, were randomly allocated to receive either lamotrigine (25 mg once daily for 1 week, 50 mg once daily for the second week, and 100 mg once daily for the last 2 weeks) or lithium (400 mg twice daily) in a 4-week randomized, double-blind, clinical trial.
Results: Both treatments improved symptoms of mania, as assessed by the Mania Rating Scale, Brief Psychiatric Rating Scale, Clinical Global Impression severity and improvement scales, and the Global Assessment of Functioning scale. There were no significant differences between groups at any time point, suggesting that the dose escalation required for lamotrigine did not adversely affect its onset of action. Secondary outcome measures, including the use of lorazepam as rescue medication, did not differ between the groups. No significant adverse events were noted in either group.
Conclusion: In this pilot study, lamotrigine was as effective as lithium in the treatment of patients with bipolar disorder hospitalised for acute mania.