Abstracts

Rationale: To review the efficacy and tolerability of stiripentol in the treatment of Dravet syndrome. Methods: We collected data for Dravet syndrome patients who were treated with stiripentol from May 2012 to Apr 2016. All patients harbored SCN1A mutation. Half of the patients had missense mutations, while the others had truncation mutation including nonsense, frame shift or large deletion mutation. Information collected included demographic data, SCN1A mutational analysis, convulsive and overall seizure frequency, frequency of prolonged seizures and rescue medication use prior to stiripentol initiation and with stiripentol therapy. Patients with more than 50% seizure reduction at six months after stiripentol maintenance therapy were defined as responders. Results: In total, 14 Dravet syndrome patients received stiripentol as add-on therapy. The pateints were taking average 3 antiepileptic medications before the initiation of stiripentol. Stiripentol was initiated at a median of 7.4 years of age (range, 13 month-20 years old) and maintained for 21 months (range, 2-45 months). The median maintenance dose of stiripentol during treatment was 33.5mg/kg/day (range 5-80 mg/kg/day). Responder rate for convulsive seizures was 64% (9/14). Four of 14 patients have used rescue medication due to prolonged seizures for 3 months prior to stiripentol therapy, while none of the patients had prolonged seizures after the 3 months of stiripentol therapy. There was no significant difference in responder rate depending on the SCN1A mutation type. Adverse effects were reported in 6 patients (43%), most commonly somnolence (4 patients) and ataxia (2 patients). Only one patient discontinued stiripentol for somnolence which was considered as a major adverse effect. Conclusions: Add on stiripentol therapy seems to be effective for reducing convulsive and prolonged seizures. Although somnolence was a frequently reported adverse effect, stiripentol was well tolerated in most of the patients. Funding: None.