Clobazam: effect on frequency of seizures and safety profile in different subgroups of children with epilepsy.

Background: Clobazam has been used in clinical practice as an adjunctive treatment for diverse seizure types and epilepsy syndromes. We evaluated the efficacy and safety of clobazam in a large sample of patients with refractory epilepsy at a tertiary pediatric center.

Methods: We retrospectively reviewed patients treated with clobazam between January 2001 and July 2013 who had a follow-up visit at least one month after starting clobazam. Response was defined as ≥50% reduction in seizure frequency compared with baseline seizure frequency during the 3 months before the introduction of clobazam. We examined the relationship between dose range and response rate.

Results: Four-hundred twenty-five patients were prescribed clobazam, of whom 300 (median age 9.1 years, interquartile range 4.7-13.3 years) had follow-up data greater than 1 month. Median follow-up was 5 months (interquartile range 3-11 months). Response to treatment with clobazam was observed in 203 of 300 (67.7%) patients, of whom 84 (28%) became seizure-free. The median starting dose was 0.2 (interquartile range 0.13-0.33) mg/kg/day with a target dose of 0.48 (0.26-0.80) mg/kg/day. Twenty-seven (9%) patients discontinued clobazam, 16 (59.3%) because adverse effects, 10 (37%) because of a lack of efficacy, and one (3.7%) because of a combination of adverse effects and lack of efficacy. The most common adverse effects were tiredness in 44 of 300 (14.6%) and mood or behavioral changes in 23 (7.7%).

Conclusions: Clobazam is a well-tolerated antiepileptic drug with good response rates in pediatric patients with refractory epilepsy.