Lamotrigine rechallenge in treatment-resistant bipolar disorder

Background: Although lamotrigine may be useful for treating patients with treatment-resistant bipolar disorder, some lamotrigine-associated adverse effects, including mild to moderate skin rash, may prevent the continuation of treatment. Methods: We investigated lamotrigine rechallenge for the treatment of bipolar disorder. The present study was based on retrospective chart review of outpatients with bipolar disorder (DSM-5 criteria) who visited the hospital’s psychiatric department between July 2011 and August 2017. The review revealed 12 patients with bipolar disorder who underwent lamotrigine rechallenge following lamotrigine discontinuation due to various adverse reactions, including skin rash. None of the patients showed Stevens-Johnson syndrome. All patients suffered from treatment-resistant bipolar disorder that was refractory to treatments other than lamotrigine. For each patient, the severity of the adverse reaction to lamotrigine was weighed against the potential for therapeutic benefit. Results: In 9 of 12 cases, a positive outcome of lamotrigine rechallenge was observed. In all cases with initial skin rash with very slow titration of lamotrigine, rechallenge was successful with no recurrence of the rash. In the 3 cases for which lamotrigine was unsuccessful, lamotrigine was discontinued owing to movement disorders, ie, oral dyskinesia and action tremor, and liver dysfunction, respectively. Conclusions: The present results suggest that lamotrigine rechallenge may be a viable option for treatment-resistant bipolar disorder.