BACKGROUND

Approximately half of all patients with diagnosed bipolar disorder are prescribed 2 or more psychotropic medications. Lamotrigine was approved in 2003 for the maintenance treatment of bipolar I disorder. This study examined comparative effects of lamotrigine with and without concomitant medications.

METHODS

A post hoc analysis of data from a prospective, open-label study of lamotrigine in 1175 patients with bipolar I disorder evaluated the clinical response to and quality-of-life and weight effects of lamotrigine as monotherapy and in patients receiving concomitant valproate, lithium, antipsychotics, or antidepressants. The study was originally designed to assess the rate of rash among patients instructed to use specific dermatologic precautions compared with those receiving usual care. Lamotrigine was administered for 12 weeks, including a 5-week titration, with target dose of 200 mg/d, adjusted as necessary for concomitant medication(s). Evaluations at baseline and week 12 included the severity component of the Clinical Global Impression-Bipolar Version scale, the Quality of Life Enjoyment and Satisfaction Questionnaire Short Form, and weight and body mass index (BMI).

RESULTS

Efficacy data were available for 1139 patients. Symptoms and quality-of-life mean scores improved following treatment in all patient groups. Quality-of-life scores improved significantly more in patients not receiving than in those receiving concomitant antipsychotics. There were no changes in weight or BMI after lamotrigine monotherapy or adjuvant therapy. Most patients were satisfied with lamotrigine treatment.

CONCLUSION

Lamotrigine was effective and well tolerated and appeared to have no effect on body weight when given as monotherapy or as adjunctive therapy with valproate, antipsychotics, lithium, or antidepressants to outpatients with bipolar I disorder in a 12-week open-label study.