Abstracts

Rationale: Clobazam is a benzodiazepine medication which was approved for use by the Food and Drug Administration (FDA) as an adjunctive treatment for seizures associated with Lennox-Gastaut syndrome (LGS) in adults and children 2 years of age and older. Although used most in patients with LGS, we hypothesize that the extent of use of clobazam is broader than its approved use. We also hypothesize that it is well-tolerated. Methods: We retrospectively reviewed charts from all patients (aged 0 to <18 years) at the University of Michigan Division of Pediatric Neurology who were treated with clobazam since its approval by the FDA in October 2011. Results: Forty patients were included in the study. Median age of the cohort was 8.2 at the age that clobazam was started years (SD 4.3 years), 52.5% were male. One patient who was less than 2 years of age was treated with clobazam at our institution. The median age of seizure onset for the patients in our study was 1.5 years. The average number of anticonvulsants tried prior to clobazam was 4.8. The average starting dose of clobazam was 0.21 mg/kg/day with the average highest dose tried at 0.8 mg/kg/day. The maximum tolerated dose was 2 mg/kg/day. Side effects seen by this medication included weight gain, irritability, and somnolence. There was an average increase in weight by 5.1%ile in children 3-6 months after starting clobazam (standard deviation of 15). Besides being used in LGS [n=4], clobazam was used in multiple different epilepsy types were treated with clobazam including medically intractable symptomatic generalized epilepsy [n=26] focal epilepsy [n=7], myoclonic astatic epilepsy [2], Dravet Syndrome [n=1], focal epilepsy with electrographic status epilepticus in sleep (ESES) [n=2], treatment resistant absence epilepsy [n=1], symptomatic generalized epilepsy with ESES [n=1], and treatment resistant epilepsy with infantile spasms [n=1]. Conclusions: Clobazam is a well-tolerated antiseizure medication that can be effectively used in several types of pediatric epilepsies, not restricted to Lennox-Gastaut syndrome. Patients tolerate doses as high as 2 mg/kg/day. The most common side effects included sleepiness and irritability. Weight gain was an unexpected side effect, not previously described.