Abstracts

Rationale: Clobazam was marketed in the United States in 2012, for adjunctive therapy in patients with Lennox-Gastaut syndrome, a predominantly pediatric condition. However, it has a broad spectrum of efficacy and has been widely used in adults with various epileptic diagnoses. In view of limited data in adult populations, we evaluated our clinical experience in an adult epilepsy clinic of a single provider. Methods: We identified patients started on clobazam between 2012 and 2017, with follow-up data for at least 3 months. We excluded patients with nonepileptic seizures making it difficult to ascertain true seizure counts and patients who had epilepsy surgery during follow-up. We also excluded patients who were unable to count their seizures. We recorded clinical information for each patient including epilepsy classification, initial clobazam target dose, maximal dose, and monthly seizure frequency in the 3 months before starting clobazam, in the first 3 months of clobazam adjunctive treatment, and at last follow-up. We also calculated duration of treatment and treatment retention at last follow-up. Results: 53 patients (25 men and 28 women) qualified for the study. Their mean age was 38 years (range 19-71). The epilepsy classification was focal in 39 and generalized in 14 patients. The mean initial target dose was 17 mg (range 5-40) and the mean maximal dose was 30 mg (range 5-80 mg). At 6 months of follow-up 28 (53%) patients were responders with 50% seizure reduction; 10 (19%) were seizure-free. Among patients with focal epilepsy, 20 (51%) were responders, including 7 (18%) that were seizure-free.  Most of the seizure-free patients had been refractory to multiple AEDs.  At the last follow-up (mean clobazam treatment duration of 30 months), 47 (89%) patients were continuing clobazam. Of the 10 seizure-free patients, six were still seizure-free at last follow-up, three had rare seizures, and one was no longer a responder. Conclusions: Clobazam adjunctive therapy resulted in seizure freedom in 19% of patients, most of whom had been highly drug-resistant. Efficacy was equal for focal and generalized epilepsy. A trial of adjunctive clobazam should be considered for highly drug-resistant patients with either focal or generalized epilepsy. Funding: None