Stiripentol efficacy and safety in Dravet syndrome: a 12-year observational study

AIM To assess long-term safety and efficacy of stiripentol as an antiepileptic medication for people with Dravet syndrome. METHOD A prospective, observational open-label study (2003-2015) of the efficacy and long-term safety of stiripentol in patients with Dravet syndrome and ongoing seizures. Frequency of generalized tonic-clonic seizures, focal seizures, status epilepticus, and adverse events were recorded. RESULTS Forty-one patients started stiripentol, with median age at enrolment 5 years 7 months (range 11mo-22y) and median duration of treatment 37 months (range 2-141mo). Twenty out of 41 patients had greater than or equal to 50% long-term reduction in frequency of generalized tonic-clonic seizures. Frequency of focal seizures was decreased by greater than or equal to 50% in 11 out of 23 patients over the long-term. Frequency of status epilepticus was decreased by 50% or more in 11 out of 26 patients. The most common adverse events were anorexia, weight loss, sedation, and behavioural changes. One patient had worsening of absence and myoclonic seizures. Another developed recurrent pancreatitis on concurrent valproate. INTERPRETATION Stiripentol improves long-term seizure frequency in approximately 50% of patients with Dravet syndrome, when used as part of unrestricted polytherapy. Long-term use appears safe. In more than 40% of patients, episodes of status epilepticus markedly decrease after stiripentol initiation.