Adjunctive treatment for mood stabilization of patients with bipolar I disorder treated with lamotrigine.

Objective: To describe the effect of supplemental psychotropic medications, specifically anxiolytics with sedative/hypnotics (ASH) combined with lamotrigine (LTG) on stabilization of symptoms in patients with bipolar I disorder.

Method: Symptomatic patients participating in two LTG maintenance trials were classified post-hoc as those initiating LTG as monotherapy (n=313) or as adjunctive therapy (n=814) and further characterized by supplemental add-on therapies received during an open-label treatment phase. Patients were considered stabilized if they reached a stable dose of LTG monotherapy (100-200 mg/day) and had a Clinical Global Impressions-Severity scale score <3 for at least 4 weeks. Stabilization rates were compared across initial- and supplemental-treatment groups.

Results: Patients who initiated and were maintained on LTG monotherapy were stabilized at a slightly higher rate compared with those taking LTG adjunctive therapy (55% vs 48%; P=.080). Stabilization rates were numerically higher for LTG monotherapy patients who later received only ASH as supplemental medication compared with LTG monotherapy throughout, but this difference was not significant (66% vs 55%; P=.271). Stabilization rates were significantly higher for monotherapy patients who later received ASH alone versus other psychotropic medications (66% vs 28%; P=.001). For patients initiating LTG as adjunctive therapy, adding ASH alone resulted in significantly higher stabilization rates than adding another psychotropic medication (62% vs 33%; P<.001).

Conclusion: LTG and adjunctive treatment with ASH may be useful in the treatment of acute mood symptoms in patients with bipolar I disorder.