Long-Term Use of Clobazam in Lennox-Gastaut Syndrome: Experience in a Single Tertiary Epilepsy Center

Objective: Clobazam (CLB) is a 1,5-benzodiazepine, which is known to be effective for treating refractory partial epilepsy. We have evaluated the long-term efficacy and tolerability of CLB as an add-on therapy in patients with Lennox-Gastaut syndrome (LGS). Methods: Forty-six patients with LGS who had received CLB add-on therapy were enrolled in this study. We retrospectively reviewed their clinical characteristics, including type of seizures, use of CLB, efficacy, adverse events, and retention rate. Results: The mean +/- SD dose of CLB was 0.70 +/- 0.37 mg/kg per day (range, 0.16-1.60 mg/kg per day). After 1 month on CLB, 15 patients (32.6%) became seizure-free and 10 patients (21.7%) had 50% or greater seizure reduction. Response to CLB was not significantly associated with age, sex, or etiology (symptomatic or not). Five (10.8%) of 46 patients maintained seizure remission for more than 12 months. Tolerance developed in 48.0% of initial responders, and the 3-year retention rate by the Kaplan-Meier method was 76.6%. Seven patients (15.2%) reported adverse events, including somnolence and behavioral change, but only one discontinued CLB. Conclusions: Clobazam add-on therapy was effective and very tolerable in patients with LGS.