Lamotrigine Associated with Insomnia

PURPOSE: To review the incidence of lamotrigine (LTG)-associated insomnia in an adult tertiary care epilepsy outpatient clinic. METHODS: The records of all patients who had received LTG were reviewed to identify patients who had experienced insomnia after introduction of this drug. Patients were included if they had experienced a sleep disturbance of sufficient severity to require a discontinuation of LTG or a dose reduction. RESULTS: Among 109 patients exposed to LTG, seven (6.4%) had a sleep disturbance of a severity to required a change in therapy. The descriptions of the sleep disturbance were similar among the patients, and the LTG-induced insomnia appeared to be dose dependent. Unlike the few previous descriptions of LTG-induced insomnia in the literature, no factors predisposing to this adverse effect were identified. CONCLUSIONS: The results of this retrospective review suggest an association between LTG and intolerable insomnia in a small proportion of patients. Physicians should inquire about sleep disturbances in patients treated with LTG.