Treatment with stiripentol reduces seizures and can resolve epileptic episodes, retrospective analysis of a small study in Turkish Dravet syndrome children suggests.
The study, “Efficacy of Stiripentol and the Clinical Outcome in Dravet Syndrome,” was published in the Journal of Child Neurology.
Stiripentol, sold as Diacomit by Biocodex, is an anticonvulsant medication recently approved as an add-on therapy for Dravet syndrome by the U.S. Food and Drug Administration (FDA). The therapy was approved in Europe in 2007.
Stiripentol has a dual mode of action. It binds to GABAA receptors — a type of receptor present in brain cells — decreasing their activity and preventing seizures, which are thought to be the result of excessive brain cell activity. It also inhibits an enzyme called cytochrome P450, preventing it from acting upon certain therapies used in Dravet treatment, such as Onfi (clobazam).
A team of researchers in Istanbul retrospectively evaluated the clinical characteristics of 21 patients with Dravet syndrome — 11 girls and 10 boys — and their response to stiripentol.
Patients’ mean age was 8.2 years and seizure onset began at around 4 months of age (on average). Most participants (19) carried SCN1A mutations, affecting approximately 80 percent of all Dravet patients. The other two patients carried mutations in the SCN1B gene.
Cognitive disabilities were severe or moderate in 47 and 33 percent of the cases, respectively, with about 14 percent of patients showing mild cognitive disability.
Status epilepticus varied significantly between patients with normal to mild versus moderate to severe cognitive impairments, as well as age.
Status epilepticus, a common phenomenon in those with Dravet syndrome, describes epileptic episodes characterized by either a single seizure lasting longer than five minutes, or many seizures occurring close together without the patient recovering between them.
No significant differences in sex, type of seizure, or response to stiripentol were observed between the groups with normal to mild and severe to moderate cognitive disability.
Almost all patients (90 percent) had clinical seizures in the prior three months, with seizures occurring weekly (more than three) in 38 percent, while the others were affected by either daily (28.5 percent) or monthly (23.8 percent) seizures.
The predominant seizure types were tonic-clonic (convulsions, 33.3% of patients), clonic (sustained rhythmic jerking, 38%), myoclonic (brief shock-like jerks of a muscle, 19%) and atypical absence (characterized by staring, 10%).
Most patients (85.7 percent) received treatment with stiripentol for a mean duration of 41.2 months (range of 24-64 months).
In 12 patients, seizures’ rate decreased by more than 50 percent, and these were considered responders. Two of them became seizure-free — one, age 7, received stiripentol for 38 months; the second seizure-free patient, age 6, was on stiripentol for 24 months.
Before beginning treatment with stiripentol, 11 patients had a history of status epilepticus. Eight of them had no more status epilepticus episodes after initiating stiripentol.
In eight patients, researchers detected adverse effects, the most common being sedation and ataxia (poor control of voluntary muscles). Additional, less common adverse effects included tremor, speech slowdown, and nausea.
Overall, and despite the small number of patients, this retrospective analysis supports the therapeutic benefits of stiripentol in children with Dravet syndrome.
“Considering the low rate of status epilepticus after treatment and the negative effect of status epilepticus on cognitive development, early initiation of stiripentol could have a favorable effect in this patient population, in whom disease control is difficult,” researchers stated.