Open-label, concomitant use of lamotrigine and other medications for bipolar disorder

A post-hoc, descriptive analysis was undertaken to assess the tolerability of and changes in psychiatric rating scales with lamotrigine (LTG) administered concomitantly with commonly prescribed bipolar medications.

During the 8- to 16-week, open-label, preliminary phase of two large clinical trials of patients (N=1,305) with bipolar I disorder, LTG was added to each patient's existing psychotropic regimen. Medications for acute symptoms could have been added and later discontinued to achieve LTG monotherapy. Data were compared for patients taking LTG with or without concomitant valproate, lithium, any atypical antipsychotic, or any selective serotonin reuptake inhibitor.

The percentages of patients with any reported adverse event and reported adverse events of mood symptoms or rash were comparable between those taking LTG with or without other concomitant bipolar medications. Adverse events in >10% of patients in at least one subgroup were headache, infection, nausea, rash, influenza, diarrhea, dizziness, and somnolence. Baseline scores on psychiatric rating scales improved similarly with LTG co-administered with other bipolar medications, and the pattern of results did not differ by baseline polarity of mood symptoms.

LTG co-administered with valproate, lithium, an atypical antipsychotic, or a selective serotonin reuptake inhibitor in the treatment of bipolar disorder seemed to be well tolerated and was associated with clinical improvement.