[Long-term efficacy and tolerance of stiripentaol in severe myoclonic epilepsy of infancy (Dravet's syndrome)]

Adverse events associated with Stiripentol in children aged 0-17 years: An analysis of a real-world pharmacovigilance database

OBJECTIVE

To analyze the occurrence of adverse drug events (ADEs) associated with Stiripentol (STP) use in children aged 0-17 years in real-world clinical settings.

METHODS

ADE reports on STP in children aged 0-17 years were collected from the WHO Global Case Safety Pathology Reporting Database (VigiBase), the U.S. Food and Drug Administration's Spontaneous Adverse Event Reporting System database (FAERS), and the European Medicines Agency's Pharmacovigilance database (Eudra Vigilance). Pharmacovigilance signals were identified through Reporting Odds Ratio (ROR), and Proportional Reporting Ratio (PRR).

RESULTS

In total, 31,990 ADEs were reported with "Stiripentol" as the primary suspect drug. This includes 595 ADEs from the Eudra Vigilance, 1,353 ADEs from the FAERS, and 998 ADEs from the VigiBase. All three databases indicate a higher incidence of ADEs related to STP in the categories of nervous system disorders, general disorders and administration site conditions, injury, poisoning and procedural complications, and metabolism and nutrition disorders. A higher proportion of children aged 3-11 years reported (16.48 %-32.44 %). The FAERS data shows that cerebellar atrophy (PRR of 332.94, ROR of 532.10) is the strongest signal for children aged 0-2 years, while changes in seizure presentation (PRR of 110.76, ROR of 121.06) is the strongest signal for children aged 3-11 years. For children aged 12-17 years, seizures (PRR of 46.99, ROR of 47.40) and decreased appetite(PRR of 45.51, ROR of 45.96) are the strongest signals. The Eudra Vigilance results show that boys have higher ADEs than girls for investigations, blood and lymphatic system disorders, hepatobiliary disorders, infections and infestations in children aged 0-17 years. On the other hand, girls have higher ADEs than boys for skin and subcutaneous tissue disorders, injury, poisoning and procedural complications, general disorders and administration site conditions, and gastrointestinal disorders.

CONCLUSION

In the clinical application of STP in pediatrics, it is important to examine ADEs in Nervous system disorders, Injury, poisoning and procedural complications, General disorders and administration site conditions, and Metabolism and nutrition disorders. Further studies should confirm whether there are age and gender differences in different ADEs.

Additional Results from Two Randomized, Placebo-Controlled Trials of Stiripentol in Dravet Syndrome Highlight a Rapid Antiseizure Efficacy with Longer Seizure-Free Periods

INTRODUCTION

The efficacy of stiripentol in Dravet syndrome children was evidenced in two randomized, double-blind, placebo-controlled, phase 3 studies, namely STICLO France (October 1996-August 1998) and STICLO Italy (April 1999-October 2000), but data were not fully exploited at the time.

METHODS

This post-hoc analysis used additional information, notably collected during the open-label extension (OLE) month, or reported by caregivers in individual diaries, to evaluate new outcomes.

RESULTS

Overall, 64 patients were included (31 in the placebo group, 33 in the stiripentol group) of whom 34 (53.1%) were female. Patients' mean and median (25%; 75%) age were 9.2 years (range 3.0-20.7 years) and 8.7 years (6.0; 12.1) respectively. At the end of the double-blind treatment period, 72% of the patients in the stiripentol group had a ≥ 50% decrease in generalized tonic-clonic seizure (GTCS) frequency, versus 7% in the placebo group (P < 0.001), 56% had a profound (≥ 75%) decrease versus 3% in the placebo group (P < 0.001), and 38% were free of GTCS, but none in the placebo group (P < 0.001). The onset of stiripentol efficacy was rapid, significant from the fourth day of treatment onwards. The median longest period of consecutive days with no GTCS was 32 days in the stiripentol group compared to 8.5 days in the placebo group (P < 0.001). Further to the switch to the third month OLE, an 80.2% decrease in seizure frequency from baseline was observed in patients previously receiving placebo, while no change in efficacy was observed in those already on stiripentol. Adverse events were more frequent in the stiripentol group, with significantly more episodes of somnolence, anorexia, and weight decrease than in the placebo group.

CONCLUSION

Altogether these new analyses of the STICLO data reinforce the evidence for a remarkable efficacy of stiripentol in Dravet syndrome, with a demonstrated rapid onset of action and sustained response, as also evidenced in further post-randomized trials.

Initiating stiripentol before 2 years of age in patients with Dravet syndrome is safe and beneficial against status epilepticus

AIM

To evaluate the safety and efficacy of stiripentol initiated before 2 years of age in patients with Dravet syndrome.

METHOD

This was a 30-year, real-world retrospective study. We extracted the data of the 131 patients (59 females, 72 males) who initiated stiripentol before 2 years of age between 1991 and 2021 from the four longitudinal databases of Dravet syndrome available in France.

RESULTS

Stiripentol was added to valproate and clobazam (93%) at 13 months and a median dose of 50 mg/kg/day. With short-term therapy (<6 months on stiripentol, median 4 months, median age 16 months), the frequency of tonic-clonic seizures (TCS) lasting longer than 5 minutes decreased (p < 0.01) and status epilepticus (>30 minutes) disappeared in 55% of patients. With long-term therapy (last visit on stiripentol <7 years of age, median stiripentol 28 months, median age 41 months), the frequency of long-lasting TCS continued to decline (p = 0.03). Emergency hospitalizations dropped from 91% to 43% and 12% with short- and long-term therapies respectively (p < 0.001). Three patients died, all from sudden unexpected death in epilepsy. Three patients discontinued stiripentol for adverse events; 55% reported at least one adverse event, mostly loss of appetite/weight (21%) and somnolence (11%). Stiripentol was used earlier, at lower doses, and was better tolerated by patients in the newest database than in the oldest (p < 0.01).

INTERPRETATION

Initiating stiripentol in infants with Dravet syndrome is safe and beneficial, significantly reducing long-lasting seizures including status epilepticus, hospitalizations, and mortality in the critical first years of life.

Pharmacological diversity amongst approved and emerging antiseizure medications for the treatment of developmental and epileptic encephalopathies

Developmental and epileptic encephalopathies (DEEs) are rare neurodevelopmental disorders characterised by early-onset and often intractable seizures and developmental delay/regression, and include Dravet syndrome and Lennox-Gastaut syndrome (LGS). Rufinamide, fenfluramine, stiripentol, cannabidiol and ganaxolone are antiseizure medications (ASMs) with diverse mechanisms of action that have been approved for treating specific DEEs. Rufinamide is thought to suppress neuronal hyperexcitability by preventing the functional recycling of voltage-gated sodium channels from the inactivated to resting state. It is licensed for adjunctive treatment of seizures associated with LGS. Fenfluramine increases extracellular serotonin levels and may reduce seizures via activation of specific serotonin receptors and positive modulation of the sigma-1 receptor. Fenfluramine is licensed for adjunctive treatment of seizures associated with Dravet syndrome and LGS. Stiripentol is a positive allosteric modulator of type-A gamma-aminobutyric acid (GABAA) receptors. As a broad-spectrum inhibitor of cytochrome P450 enzymes, its antiseizure effects may additionally arise through pharmacokinetic interactions with co-administered ASMs. Stiripentol is licensed for treating seizures associated with Dravet syndrome in patients taking clobazam and/or valproate. The mechanism(s) of action of cannabidiol remains largely unclear although multiple targets have been proposed, including transient receptor potential vanilloid 1, G protein-coupled receptor 55 and equilibrative nucleoside transporter 1. Cannabidiol is licensed as adjunctive treatment in conjunction with clobazam for seizures associated with Dravet syndrome and LGS, and as adjunctive treatment of seizures associated with tuberous sclerosis complex. Like stiripentol, ganaxolone is a positive allosteric modulator at GABAA receptors. It has recently been licensed in the USA for the treatment of seizures associated with cyclin-dependent kinase-like 5 deficiency disorder. Greater understanding of the causes of DEEs has driven research into the potential use of other novel and repurposed agents. Putative ASMs currently in clinical development for use in DEEs include soticlestat, carisbamate, verapamil, radiprodil, clemizole and lorcaserin.

Current and promising therapeutic options for Dravet syndrome

INTRODUCTION

Dravet Syndrome (DS) is a developmental and epileptic encephalopathy carrying high-level psychobehavioral burdens. Although the disease has been known for almost 4 decades, and despite significant progress in the understanding of its physiopathology and natural course, the pharmacological treatment leaves patients and caregivers with significant unmet needs. This review provides a summary of the current and promising therapeutic options for DS.

AREAS COVERED

PubMed and ClinicalTrials.gov were screened using 'Dravet Syndrome' OR 'DS,' AND 'pharmacotherapy,' AND 'treatments.' Randomized clinical trials, structured reviews, and meta-analyses were selected for in-human application of well-known anti-seizure medications; while in-vivo experiments on models of DS were selected to evaluate the potential of new therapeutic strategies.

EXPERT OPINION

The search for new pharmacological treatment options is led by the need for care and defeat of the natural course of the disease, an aspect still largely neglected by the available therapeutic strategies. Yet, the last 6 years have led to a climate of increased interest and availability of clinical trials. Particularly, gene therapy could hopefully prevent DS evolution by directly relieving the specific genetic defect, although the possibility of off-target editing, and the uneasy administration route have still largely prevented its use.

Impact of Antiseizure Medications on Appetite and Weight in Children

There are numerous potential factors that may affect growth in children with epilepsy, and these must be evaluated in any child with appetite and weight concerns. Antiseizure medications (ASMs) have potential adverse effects, and many may affect appetite, thus impacting normal growth and weight gain. The aim of this review is to focus on the impact of both epilepsy and ASMs on appetite and weight in children. We systematically reviewed studies using Medline assessing the impact of ASMs on appetite and weight in children. Eligible studies included randomized controlled trials and open-label studies (open-label extension and interventional) that targeted or included the pediatric population (0-18 years of age). Each study was classified using the American Academy of Neurology (AAN) Classification of Evidence for Therapeutic Studies, and the level of evidence for impact on appetite and weight in children was graded. ASMs associated with decreased appetite and/or weight loss include fenfluramine, topiramate, zonisamide, felbamate, rufinamide, stiripentol, cannabidiol, brivaracetam and ethosuximide; ASMs with minimal impact on weight and appetite in children include oxcarbazepine, eslicarbazepine, lamotrigine, levetiracetam, lacosamide, carbamazepine, vigabatrin and clobazam. The ASM most robustly associated with increased appetite and/or weight gain is valproic acid; however, both pregabalin and perampanel may also lead to modest weight gain or increased appetite in children. Certain ASMs may impact both appetite and weight, which may lead to increased morbidity of the underlying disease and impaired adherence to the treatment regimen.

A Practical Guide to the Treatment of Dravet Syndrome with Anti-Seizure Medication

Dravet syndrome is a severe developmental and epileptic encephalopathy characterised by refractory seizures and cognitive dysfunction. The treatment is challenging, not least because the seizures are highly drug resistant, requiring multiple anti-seizure medications (ASMs), while some ASMs can exacerbate seizures. Initial treatments include the broad-spectrum ASMs valproate (VPA), and clobazam (CLB) in some regions; however, they are generally insufficient to control seizures. With this in mind, three adjunct ASMs have been approved specifically for the treatment of seizures in patients with Dravet syndrome: stiripentol (STP) in 2007 in the European Union and 2018 in the USA, cannabidiol (CBD) in 2018/2019 (in combination with CLB in the European Union) and fenfluramine (FFA) in 2020. These "add-on" therapies (mostly to VPA/CLB) are used as escalation therapies, with the choice dependent on availability in different countries, patient characteristics and caregiver preferences. Topiramate is also frequently used, with evidence of efficacy in Dravet syndrome, and there is anecdotal evidence of efficacy with bromide, which is frequently used in Germany and Japan. With a growing treatment landscape for Dravet syndrome, there can be practical challenges for clinicians, particularly with issues associated with polypharmacy. This practical guide provides an overview of these main ASMs including their indications/contraindications, mechanism of action, efficacy, safety and tolerability profile, dosage requirements, and laboratory and clinical parameters to be evaluated. Standard laboratory and clinical parameters include blood counts, liver function tests, serum concentrations of ASMs, monitoring the growth of children, as well as weight loss and acceleration of behavioural problems. Regular cardiac monitoring is also important with FFA as it has previously been associated with cases of cardiac valve disease when used in adults at high doses (up to 120 mg/day) in combination with phentermine as a therapy for obesity. Importantly, no signs of heart valve disease have been documented to date at the low doses used in patients with developmental and epileptic encephalopathies. In addition, potential drug-drug interactions and their consequences are a key consideration in everyday practice. Interactions that potentially require dosage adjustments to alleviate adverse events include the following: STP + CLB resulting in increased plasma concentrations of CLB and its active metabolite norclobazam may increase somnolence, and an interaction with STP and VPA may increase gastrointestinal adverse events. Cannabidiol has a bi-directional interaction with CLB producing an increase in plasma concentrations of 7-OH-CBD and norclobazam resulting in the potential for increased somnolence and sedation. In addition, CBD is associated with elevations of liver transaminases particularly in patients taking concomitant VPA. The interaction between FFA and STP requires a dose reduction of FFA. Furthermore, concomitant administration of VPA with topiramate has been associated with encephalopathy and/or hyperammonaemia. Finally, we briefly describe other ASMs used in Dravet syndrome, and current key clinical trials.

Guidance on Dravet syndrome from infant to adult care: Road map for treatment planning in Europe

Dravet syndrome (DS) is a severe, rare, and complex developmental and epileptic encephalopathy affecting 1 in 16 000 live births and characterized by a drug‐resistant epilepsy, cognitive, psychomotor, and language impairment, and behavioral disorders. Evidence suggests that optimal treatment of seizures in DS may improve outcomes, even though neurodevelopmental impairments are the likely result of both the underlying genetic variant and the epilepsy. We present an updated guideline for DS diagnosis and treatment, taking into consideration care of the adult patient and nonpharmaceutical therapeutic options for this disease. This up‐to‐date guideline, which is based on an extensive review of the literature and culminates with a new treatment algorithm for DS, is a European consensus developed through a survey involving 29 European clinical experts in DS. This guideline will serve professionals in their clinical practice and, as a consequence, will benefit DS patients and their families.

Safety considerations selecting antiseizure medications for the treatment of individuals with Dravet syndrome

Introduction: Management of individuals with Dravet Syndrome has evolved significantly over the past 10 years. Progress has been made in understanding the pathophysiology, the long-term outcome and possible consequences of inappropriate therapies, new drugs have been approved by the regulatory authorities and patients and families expressed their needs beyond seizures' control.Areas covered: The authors aimed at providing an overview of the main antiseizure medications used in Dravet syndrome with a particular focus on safety considerations. As the highly active phase of seizures takes place before the age of 5 years, the characteristics of antiseizure medications in infancy and childhood have also been considered due to their impact on antiseizure medication safety.Expert opinion: Recent treatments, evaluated via randomized clinical trials, are promising in terms of efficacy and safety in individuals with DS. However, the balance between expected benefits and risks taken must be accurately assessed on an individual basis. There is a lack of data to understand the needs of patients and families, a major point particularly in this population, where the evaluation of efficacy and safety beyond seizures is difficult due to cognitive delay and behavioral disorders and where this evaluation is coming almost exclusively from caregivers.

Stiripentol: A Review in Dravet Syndrome

Stiripentol (Diacomit^®) is an orally-active, structurally unique anti-epileptic drug (AED) with multiple potential mechanisms of action, including enhancement of central γ-aminobutyric acid transmission. In the EU, stiripentol is indicated for use in conjunction with clobazam and valproate as adjunctive therapy of refractory generalized tonic-clonic seizures in patients with Dravet syndrome (DS; previously known as severe myoclonic epilepsy of infancy), whose seizures are not adequately controlled with clobazam and valproate. This approval (and similar DS indications in the USA, Canada and Japan), reflect the results of the STICLO studies, two small, randomized controlled trials in which stiripentol as adjunctive therapy was associated with a markedly superior response rate after 2 months compared with placebo in patients aged between 3 and ≈ 21 years with DS that was inadequately controlled with clobazam and valproate. These short-term results have subsequently been supported and extended by findings from longer-term, open-label, observational studies, including a retrospective longitudinal cohort study, which showed that the efficacy of combining stiripentol with clobazam and valproate when started at paediatric age was maintained in mid-adulthood with up to 24 years of exposure, and up to 40 years of age. Drowsiness, appetite loss, weight loss, ataxia and tremor are the most common adverse events associated with the addition of stiripentol to clobazam and valproate. Based on the available evidence, stiripentol, as an adjunct to clobazam and valproate, is a demonstrably beneficial and generally well-tolerated second-line treatment for patients with DS.

GRIN2A -Related Severe Epileptic Encephalopathy Treated with Memantine: An Example of Precision Medicine

Epileptic spasm (ES) is one of the seizure types which is difficult to treat. Next-generation sequencing has facilitated rapid gene discovery that is linked to ES and GRIN2A being one of them. Genotype-driven precision medicine is on the horizon and is a targeted treatment approach toward the precise molecular cause of the disease. GRIN2A gene encodes for a subunit of N-methyl-D-aspartate (NMDA) receptor and it has been suggested from in vitro studies and few case reports that memantine, a NMDA receptor antagonist, was shown to reduce seizures in patients with GRIN2A mutations. Here, we describe a patient with a novel GRIN2A mutation and severe drug-resistant ES who became seizure free with memantine.

Recent Advances in the Drug Treatment of Dravet Syndrome

Dravet syndrome is a rare but severe epilepsy syndrome that begins in the first year of life with recurrent seizures triggered by fever that are typically prolonged and hemiclonic. The epilepsy is highly drug resistant. Although development is normal at onset, over time, most patients develop moderate-to-severe intellectual disability, behavior disorders, and a characteristic crouch gait. There is a significant mortality, predominantly owing to sudden unexpected death in epilepsy. Complete seizure control is rarely attainable. Initial therapy includes valproic acid and clobazam, but response is typically inadequate. The results of new drugs for Dravet syndrome, including stiripentol, cannabidiol, and fenfluramine, are very promising. Stiripentol was associated with a greater than 50% reduction in convulsive seizure frequency in 71% of cases, when added to valproic acid and clobazam, and also markedly reduced status epilepticus. Pharmaceutical-grade cannabidiol resulted in a median change in monthly motor seizures from baseline of - 36.5%. Fenfluramine was associated with a greater than 50% reduction in seizures of 70%, with one quarter of cases achieving near seizure freedom over the duration of the trial. These agents are generally well tolerated, with few patients discontinuing for adverse effects. There is limited evidence to date regarding improvement in cognition with these newer agents; however, a meaningful change is challenging to assess over short trial periods and requires longer follow-up studies. While current treatments focus predominantly on seizure control, newer therapies including genetic treatments and antisense oligonucleotides can target the SCN1A channelopathy, and thus, may also significantly impact the important co-morbidities associated with this syndrome.

Treatment Strategies for Dravet Syndrome

Dravet syndrome (DS) is a medically refractory epilepsy that onsets in the first year of life with prolonged seizures, often triggered by fever. Over time, patients develop other seizure types (myoclonic, atypical absences, drops), intellectual disability, crouch gait and other co-morbidities (sleep problems, autonomic dysfunction). Complete seizure control is generally not achievable with current therapies, and the goals of treatment are to balance reduction of seizure burden with adverse effects of therapies. Treatment of co-morbidities must also be addressed, as they have a significant impact on the quality of life of patients with DS. Seizures are typically worsened with sodium-channel agents. Accepted first-line agents include clobazam and valproic acid, although these rarely provide adequate seizure control. Benefit has also been noted with stiripentol, topiramate, levetiracetam, the ketogenic diet and vagal nerve stimulation. Several agents presently in development, specifically fenfluramine and cannabidiol, have shown efficacy in clinical trials. Status epilepticus is a recurring problem for patients with DS, particularly in their early childhood years. All patients should be prescribed a home rescue therapy (usually a benzodiazepine) but should also have a written seizure action plan that outlines when rescue should be given and further steps to take in the local hospital if the seizure persists despite home rescue therapy.

Stiripentol in the Management of Epilepsy

Stiripentol is a structurally unique antiepileptic drug that has several possible mechanisms of action, including diverse effects on the gamma-aminobutyric acid (GABA)-_A receptor and novel inhibition of lactate dehydrogenase. Because of its inhibition of several cytochrome P450 enzymes, it has extensive pharmacokinetic interactions, which often necessitates reduction in doses of certain co-therapies, particularly clobazam. Stiripentol also has a neuroprotective action, by reducing calcium-mediated neurotoxicity. Evidence of its efficacy is most robust for Dravet syndrome, where stiripentol added to clobazam and valproic acid reduces seizure frequency and severity in the majority of cases. Small case series have also suggested benefit for malignant migrating partial seizures in infancy, super-refractory status epilepticus, and intractable focal epilepsy, although larger prospective studies are needed in these disorders.

Optimizing the Diagnosis and Management of Dravet Syndrome: Recommendations From a North American Consensus Panel

OBJECTIVES

To establish standards for early, cost-effective, and accurate diagnosis; optimal therapies for seizures; and recommendations for evaluation and management of comorbidities for children and adults with Dravet syndrome, using a modified Delphi process.

METHODS

An expert panel was convened comprising epileptologists with nationally recognized expertise in Dravet syndrome and parents of children with Dravet syndrome, whose experience and understanding was enhanced by their active roles in Dravet syndrome associations. Panelists were asked to base their responses to questions both on their clinical expertise and results of a literature review that was forwarded to each panelist. Three rounds of online questionnaires were conducted to identify areas of consensus and strength of that consensus, as well as areas of contention.

RESULTS

The panel consisted of 13 physicians and five family members. Strong consensus was reached regarding typical clinical presentation of Dravet syndrome, range of electroencephalography and magnetic resonance imaging findings, need for genetic testing, critical information that should be conveyed to families at diagnosis, priorities for seizure control and typical degree of control, seizure triggers and recommendations for avoidance, first- and second-line therapies for seizures, requirement and indications for rescue therapy, specific recommendations for comorbidity screening, and need for family support. Consensus was not as strong regarding later therapies, including vagus nerve stimulation and callosotomy, and for specific therapies of associated comorbidities. Beyond the initial treatment with benzodiazepines and use of valproate, there was no consensus on the optimal in-hospital management of convulsive status epilepticus.

CONCLUSIONS

We were able to identify areas where there was strong consensus that we hope will (1) inform health care providers on optimal diagnosis and management of patients with Dravet syndrome, (2) support reimbursement from insurance companies for genetic testing and Dravet syndrome-specific therapies, and (3) improve quality of life for patients with Dravet syndrome and their families by avoidance of unnecessary testing and provision of an early accurate diagnosis allowing optimal selection of therapeutic strategies.

Pharmacotherapy for Dravet Syndrome

Dravet syndrome (DS) is an intractable pediatric epilepsy syndrome, starting in early childhood. This disorder typically manifests with febrile status epilepticus, and progresses to a multifocal epilepsy with febrile and non-febrile seizures with encephalopathy. Most cases are due to a mutation in the SCN1A gene. This article reviews treatments for DS, with an emphasis on pharmacotherapy. While many medications are used in treating the seizures associated with DS, these patients typically have medically refractory epilepsy, and polytherapy is often required. First-line agents include valproate and clobazam, although there are supportive data for topiramate, levetiracetam, stiripentol and the ketogenic diet. Other agents such as fenfluramine are promising therapies for Dravet syndrome. Sodium channel-blocking anticonvulsants such as carbamazepine and lamotrigine are generally contraindicated in this syndrome. Nonpharmacologic therapies (such as neurostimulation or surgery) are understudied in DS. Because DS is a global encephalopathy, pharmacologic treatment of non-epileptic manifestations of the disease is often necessary. Attention-deficit hyperactivity disorder is often encountered in patients with DS, and psychostimulants can be helpful for this indication. Other psychoactive drugs are less studied in this context. Extrapyramidal and gait disorders are often encountered in DS as well. While DS is a severe epileptic encephalopathy with a high (up to 15 %) mortality rate in childhood, careful pharmacologic management can improve these patients' clinical picture and quality of life.

Stiripentol and vigabatrin current roles in the treatment of epilepsy

INTRODUCTION

Stiripentol and vigabatrin are the two anticonvulsant drugs currently approved in severe infantile-onset epilepsies, respectively Dravet syndrome and infantile spasms.

AREAS COVERED

For both, the indication was discovered by chance thanks to an exploratory study. Both demonstrated indisputable efficacy through randomized-controlled trials. Stiripentol as adjunctive therapy to clobazam and valproate performed better than placebo, and vigabatrin as first-line monotherapy better than the reference steroid therapy in spasms due to tuberous sclerosis. At one-year treatment vigabatrin and steroids were equally efficient in the other etiologies of spasms. However, it took more than 20 years for both drugs to be approved world-wide.

EXPERT OPINION

Stiripentol suffered from pharmacokinetic potentiation of clobazam, thus raising the question whether it was efficient per se. Finally, animal models and pharmacogenetic data on CYP2C19 confirmed its specific anticonvulsant effect. Stiripentol (in comedication with clobazam and valproate) is therefore to be recommended for Dravet patients. Vigabatrin was found to have a frequent and irreversible retinal toxicity, which required an alternative visual testing to be detected in young children. Today the benefit/risk ratio of vigabatrin as first-line is considered to be positive in infantile spasms, given the severity of this epilepsy and the lack of a safer alternative therapy.

Pharmacological considerations in the use of stiripentol for the treatment of epilepsy

INTRODUCTION

Despite the fact that more than 20 antiepileptic drugs (AEDs) are currently available, about one-third of patients still present drug resistance. Further efforts are required to develop novel and more efficacious therapeutic strategies, especially for refractory epileptic syndromes showing few and anecdotic therapeutic options.

AREAS COVERED

Stiripentol (STP) is a second generation AED that shows GABAergic activity, with immature brain selectivity, and an indirect metabolic action on co-administered AEDs. Two pivotal studies demonstrated STP efficacy in patients with Dravet syndrome with refractory partial seizures, and marketing authorization in Europe, Canada and Japan was granted thereafter. Post-marketing surveys reported a good efficacy and tolerability profile. In addition, interesting data is currently emerging regarding off-label experimentation of STP in other forms of epilepsy.

EXPERT OPINION

STP is an important addition to the limited treatment options available for patients resistant to common AEDs. The possibility to inhibit seizures through the metabolic pathway of lactate dehydrogenase and the inhibitory effects on the entry of Na(+) and Ca(2+) are the most recent findings to emerge about STP and could be proof of its neuroprotective action. Moreover, its positive effects on cognitive function, its good safety and tolerability profile and the increasing data about STP efficacy on other refractory epileptic syndromes may prove to be fertile grounds for further investigation.

Drosophila sodium channel mutations: Contributions to seizure-susceptibility

This paper reviews Drosophila voltage-gated Na(+) channel mutations encoded by the para (paralytic) gene and their contributions to seizure disorders in the fly. Numerous mutations cause seizure-sensitivity, for example, para(bss1), with phenotypes that resemble human intractable epilepsy in some aspects. Seizure phenotypes are also seen with human GEFS+ spectrum mutations that have been knocked into the Drosophila para gene, para(GEFS+) and para(DS) alleles. Other para mutations, para(ST76) and para(JS) act as seizure-suppressor mutations reverting seizure phenotypes in other mutants. Seizure-like phenotypes are observed from mutations and other conditions that cause a persistent Na(+) current through either changes in mRNA splicing or protein structure.

The challenges and innovations for therapy in children with epilepsy

Major advances have been made in the diagnosis, evaluation and management of children with epilepsy over the past 15 years. There has been a marked increase in genetic diagnoses of a number of key childhood-onset epilepsy syndromes, such as Dravet syndrome, which has been linked to mutations in the SCN1A gene. The reorganization and reclassification of epilepsies, devised by the International League Against Epilepsy, has stimulated specialists to reassess their diagnostic practices; however, many studies have not addressed the global issues in treating children with epilepsy-specifically, the challenges of diagnosis through to optimal, and appropriate, therapeutic management. Also, Class I evidence-based data that are needed as a foundation for the development of treatment guidelines worldwide are lacking. Epilepsy is common, and the impact of this disease crosses age ranges and should be managed at all levels of care from community to quaternary care. In this Review, existing data and new therapeutic management approaches are discussed with the aim of highlighting the incidence of standard practices that may not be based on clinical evidence.

Efficacy of lacosamide as adjunctive therapy in children with refractory epilepsy

Lacosamide is a US Food and Drug Administration (FDA)-approved antiepileptic drug for patients 17 years or older with partial epilepsy. There are sparse data on children. The objective of our study was to evaluate its efficacy/safety in children with refractory epilepsy. Forty children (mean age 14.3 years) were treated with lacosamide at our institution (adjunctive therapy in 36, monotherapy in 4). Fifteen patients had symptomatic focal epilepsy, 2 had cryptogenic focal epilepsy, 20 had symptomatic generalized epilepsy, and 3 had cryptogenic generalized epilepsy. Two had juvenile myoclonic epilepsy and 5 had Lennox-Gastaut syndrome. Forty-two percent had at least >50% reduction in seizure frequency, and 6 became seizure free. Average dose was 7 mg/kg/d and average follow-up was 9.2 months. Responders had a 76.5% mean decrease in seizures. Fifteen children experienced an adverse reaction and 7 discontinued lacosamide (4: Ineffective, I: insurance denial, 1: tremor, 1: behavior). Lacosamide is effective and well-tolerated in children with refractory epilepsy.

Antiepileptic drugs for the treatment of severe myoclonic epilepsy in infancy

BACKGROUND

Severe myoclonic epilepsy in infants (SMEI), also known as Dravet syndrome, is a rare, refractory form of epilepsy, for whose treatment stiripentol (STP) has been recently licensed for add-on use.

OBJECTIVES

To evaluate the efficacy and tolerability of STP and other antiepileptic drug treatments (including ketogenic diet) as therapy for patients with SMEI.

SEARCH METHODS

We searched the Cochrane Epilepsy Group Specialised Register (15 May 2013), the Cochrane Central Register of Controlled Trials (CENTRAL, Issue 4 of 12, The Cochrane Library, April 2013), MEDLINE (1946 to May 2013) and SCOPUS (1823 to May 2013). The online trials registries ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform were systematically searched. The bibliographies of any identified study were searched for further references. We handsearched selected journals and conference proceedings. No language restrictions were imposed.

SELECTION CRITERIA

Randomised controlled trials (RCTs) or quasi-randomised controlled trials; double- or single-blinded or unblinded trials; and parallel-group studies. Administration of at least one antiepileptic drug therapy given singly (monotherapy) or in combination (add-on therapy) compared with add-on placebo or no add-on treatment.

DATA COLLECTION AND ANALYSIS

Review authors independently selected trials for inclusion according to predefined criteria, extracted relevant data and evaluated the methodological quality of trials. The following outcomes were assessed: at least 50% seizure reduction, seizure freedom, adverse effects, proportion of dropouts and quality of life. Outcomes were assessed using a Mantel-Haenszel meta-analysis to calculate risk ratio (RR) with 95% confidence intervals (95% CIs).

MAIN RESULTS

No RCTs assessing drugs other than STP were found. Two RCTs evaluating the use of STP (total of 64 children) were included. Both studies were generally at unclear risk of bias. A significantly higher proportion of participants had 50% or greater reduction in seizure frequency in the STP group compared with the placebo group (22/33 vs 2/31; RR 10.40, 95% CI 2.64 to 40.87). A significantly higher proportion of participants achieved seizure freedom in the STP group compared with the placebo group (12/33 vs 1/31; RR 7.93, 95% CI 1.52 to 41.21). No significant difference in the proportion of dropouts was found in the STP group compared with the placebo group (2/33 vs 8/31; RR 0.24, 95% CI 0.06 to 1.03). Only one study explicitly reported the occurrence of side effects; higher proportions of participants were reported to experience side effects in the STP group compared with the placebo group (100% vs 25%; RR 3.73, 95% CI 1.81 to 7.67).

AUTHORS' CONCLUSIONS

Data derived from two small RCTs indicate that STP is significantly better than placebo with regards to 50% or greater reduction in seizure frequency and seizure freedom. Adverse effects occurred more frequently with STP. Further adequately powered studies with long-term follow-up should be conducted to unequivocally establish the long-term efficacy and tolerability of STP in the treatment of SMEI.

Synergistic GABA-enhancing therapy against seizures in a mouse model of Dravet syndrome

Seizures remain uncontrolled in 30% of patients with epilepsy, even with concurrent use of multiple drugs, and uncontrolled seizures result in increased morbidity and mortality. An extreme example is Dravet syndrome (DS), an infantile-onset severe epilepsy caused by heterozygous loss of function mutations in SCN1A, the gene encoding the brain type-I voltage-gated sodium channel NaV1.1. Studies in Scn1a heterozygous knockout mice demonstrate reduced excitability of GABAergic interneurons, suggesting that enhancement of GABA signaling may improve seizure control and comorbidities. We studied the efficacy of two GABA-enhancing drugs, clonazepam and tiagabine, alone and in combination, against thermally evoked myoclonic and generalized tonic-clonic seizures. Clonazepam, a positive allosteric modulator of GABA-A receptors, protected against myoclonic and generalized tonic-clonic seizures. Tiagabine, a presynaptic GABA reuptake inhibitor, was protective against generalized tonic-clonic seizures but only minimally protective against myoclonic seizures and enhanced myoclonic seizure susceptibility at high doses. Combined therapy with clonazepam and tiagabine was synergistic against generalized tonic-clonic seizures but was additive against myoclonic seizures. Toxicity determined by rotorod testing was additive for combination therapy. The synergistic actions of clonazepam and tiagabine gave enhanced seizure protection and reduced toxicity, suggesting that combination therapy may be well tolerated and effective for seizures in DS.

Treatment strategies

There has been important progress in the identification of antiepileptic compounds and their indications in children over the past 15 years: their number has doubled and specific pediatric trials are being performed to document their effect according to seizures and syndromes as well as their tolerability in pediatrics. The improved understanding of pharmacokinetics and drug-drug interactions has helped to optimize treatment. Specific issues specific of infants have also been studied although new antiepileptic drugs are still dramatically lacking for this age group. Before reaching a syndromic diagnosis, the choice of a first- line agent goes to compounds with the largest range of efficacy and least identified risks. Subsequent choices are mainly based on the epilepsy syndrome and seizure type in addition to good clinical practice to determine dose, adverse effect profile, risk of aggravating seizures and drug interactions, clinician's experience, cultural habits, and availability of drugs. If there are several options, preference is given to the compound that exhibits the best risk/benefit ratio, or the most rapid titration when seizure frequency is the major issue. For new antiepileptic compounds, price is often a limiting factor in countries with poor insurance coverage. Third generation anti-epileptic drugs are emerging which also seem to be promising.

Stiripentol : in severe myoclonic epilepsy of infancy (dravet syndrome)

Stiripentol is an anticonvulsant used as adjunctive therapy with valproate and clobazam in the management of patients with severe myoclonic epilepsy of infancy (SMEI; Dravet syndrome), a rare form of epilepsy that develops in the first year of life and is subsequently associated with significant morbidity and mortality. Results of a randomized, double-blind trial, in which patients (≥3 years of age) whose SMEI was inadequately controlled with valproate and clobazam received adjunctive therapy with stiripentol or placebo for 2 months, showed a significantly higher response rate in the stiripentol group compared with the placebo group (71 % vs. 5 %; p < 0.0001; primary endpoint). Responders were defined as those patients who experienced a ≥50 % reduction in clonic or tonic-clonic seizure frequency during the second month of the double-blind period compared with baseline. Almost half of the stiripentol recipients were seizure free during this period compared with none in the placebo group. Stiripentol was also statistically superior to placebo for secondary efficacy outcomes in the randomized controlled trial, which included the median number of seizures during the second month of the double-blind period and the mean percentage change from baseline in seizure frequency. These results are supported by efficacy data from other studies in patients with SMEI treated with stiripentol as adjunctive therapy, including a long-term retrospective analysis, prospectively conducted open-label studies and a meta-analysis. Drowsiness, loss of appetite and weight loss are the most frequently reported adverse events with stiripentol, and the drug inhibits various cytochrome P450 isoenzymes, potentially leading to clinically significant drug interactions. Stiripentol is an important addition to the limited treatment options available for the management of patients with SMEI.

Stiripentol: an example of antiepileptic drug development in childhood epilepsies

The efficacy of stiripentol (STP) in Dravet Syndrome (DS) was discovered first in an exploratory study in pediatric pharmacoresistant epilepsies. This efficacy signal, used as a proof of concept, led to - two independent multicenter randomized, double-blind, placebo-controlled trials in DS patients: STICLO-France and STICLO-Italy. In adjunction to valproate and clobazam, STP demonstrated marked efficacy and these trials became the basis for the registration of STP as an orphan drug for DS. Although STP had previously shown antiepileptic activity, since it inhibits cytochromes P450, the increased plasma levels of clobazam (CLB), norclobazam (NCLB), and NCLB/CLB ratio reported in STICLO studies brought into question the activity of STP per se. Recent pharmacological studies demonstrated that (i) STP is a direct allosteric modulator of the GABA receptors at a site distinct from benzodiazepines; (ii) STP and CLB/NCLB act independently at GABA(A) receptors; (iii) their combination increases the maximum response beyond that of either drug alone. All these effects are independent of considerations of changes in metabolism. Some responders in STICLO studies failed to display any increase of plasmatic concentrations of NCLB/CLB ratio as STP could not inhibit CYP2C19 because of its inhibition by progabide or due to an inactivating CYP polymorphism. The responder rate proved to be in the same range whether the NCLB/CLB ratio increased or not. These analyses confirmed that the effects of STP cannot result from a simple pharmacokinetic interaction. We propose that the success of STP should serve as a model for AED development in rare pediatric epileptic syndromes.

Specific safety and tolerability considerations in the use of anticonvulsant medications in children

Epilepsy is one of the most common neurological disorders in the pediatric age range, and the majority of affected children can be safely and effectively treated with antiepileptic medication. While there are many antiepileptic agents on the market, specific drugs may be more efficacious for certain seizure types or electroclinical syndromes. Furthermore, certain adverse effects are more common with specific classes of medication. Additionally patient-specific factors, such as age, race, other medical conditions, or concurrent medication use may result in higher rates of side effects or altered efficacy. Significant developmental changes in gastric absorption, protein binding, hepatic metabolism, and renal clearance are seen over the pediatric age range, which impact pharmacokinetics. Such changes must be considered to determine optimal dosing and dosing intervals for children at specific ages. Furthermore, approximately one third of children require polytherapy for seizure control, and many more take concurrent medications for other conditions. In such children, drug–drug interactions must be considered to minimize adverse effects and improve efficacy. This review will address issues of antiepileptic drug efficacy, tolerability and ease of use, pharmacokinetics, and drug–drug interactions in the pediatric age range.

Pharmacologic treatment of intractable epilepsy in children: a syndrome-based approach

The successful pharmacologic treatment of intractable childhood epilepsy is predicated upon an accurate classification of the epilepsy syndrome. The selection of an antiepileptic drug is facilitated by the knowledge of syndrome-specific efficacy, the anticipation of potential side effects, and a careful risk-benefit assessment tailored to each patient. As such, the identification of comorbidities and careful monitoring for treatment-emergent adverse events, especially cognitive and behavioral effects, is of utmost importance. Especially in refractory cases, polypharmacy may increase the likelihood of side effects, but carefully chosen combinations can result in synergistic benefit. For most epilepsy syndromes, newer antiepileptic drugs typically yield equivalent efficacy and superior tolerability. Nevertheless, continued research is needed to further contrast the syndrome-specific efficacy and tolerability of available drugs and to foster the development of new agents with superior efficacy and side effect profiles.

Current therapeutic procedures in Dravet syndrome

Dravet syndrome is a highly pharmaco-resistant form of epilepsy. Valproate and benzodiazepines are the first-line treatment but are usually insufficient therapeutic options. Lamotrigine, carbamazepine and high doses of intravenous phenobarbital can aggravate seizures and should be avoided. Topiramate, levetiracetam, bromide and ketogenic diet also provide substantial efficacy as adjunctive therapy and procedures. Stiripentol is the only new drug to demonstrate efficacy when combined with valproate and clobazam, as shown in two independent double-blind controlled trials dedicated to Dravet children. In order to avoid side effects (mainly loss of appetite and loss of weight) resulting from the inhibition of cytochromes P450 by stiripentol, the prescribed doses of valproate and clobazam should be reduced. Stiripentol has a proper antiepileptic effect and enhances GABAergic neurotransmission by acting on the alpha-3 subunit of GABA(A) receptors. Stiripentol was approved as an orphan drug in Europe in 2007 for adjunctive therapy in Dravet syndrome. More than 500 Dravet patients have currently been satisfactorily treated and recent experiments in Japan have confirmed stiripentol's benefit. In practice, valproate should be initiated at the first onset of complicated febrile seizure in Dravet patients. Relapses justify the addition of clobazam and stiripentol when available. Topiramate and a ketogenic diet are alternatives in pharmaco-resistant cases.

Treatment options for epileptic myoclonus and epilepsy syndromes associated with myoclonus

BACKGROUND

Myoclonus is a brief shock-like movement that has many different etiologies. The degree to which it disturbs quality of life is extremely variable, as is its response to treatment.

OBJECTIVE

In this review, we focus on the treatment strategies for epileptic myoclonus in some common disorders, and in others that are not so common but where myoclonus is a prominent feature and has been studied more.

METHODS

An extended literature review in the English language was conducted through PubMed and text books.

CONCLUSION

Epileptic myoclonus is a manifestation of cortical irritability. The precise etiology is important when determining the best course of treatment. Response to treatment is variable and usually depends on the epileptic syndrome. Some antiepileptic drugs may worsen myoclonus even in patients with syndromes where most patients have a good response to that same drug. Therefore, clinicians must always have in mind that worsening in myoclonus may be ameliorated by decrease or withdrawal rather than increase of medication.

Managing severe epilepsy syndromes of early childhood

Managing severe epilepsy syndromes of early childhood is challenging as the seizures are typically resistant to treatment and may cause disabling mental and behavioral problems in later life. A comprehensive treatment plan includes pharmacologic, nonpharmacologic, and surgical options. This article reviews clinical studies examining the efficacies of antiepileptic medications in reducing seizure frequency in Dravet syndrome, Doose syndrome, and Lennox-Gastaut syndrome. The benefits of the ketogenic diet for children with these severe epilepsies, together with the advantages of vagus nerve stimulation and corpus callosotomy in those patients with Lennox-Gastaut syndrome, are also discussed. Special treatment considerations for each syndrome are also highlighted to improve the management of patients with these syndromes.

Dravet syndrome (severe myoclonic epilepsy in infancy): a retrospective study of 16 patients

To report the authors' experience with diagnosis and management of Dravet syndrome, or severe myoclonic epilepsy in infancy, in the era of commercially available genetic testing, the authors performed a retrospective study of 16 patients diagnosed with Dravet syndrome at a tertiary care pediatric epilepsy center. They analyzed their clinical presentation, electroencephalographic findings, genetic (SCN1A gene) results, and treatment responses and compared the findings to previous reports. The patients presented with all the previously described characteristics of Dravet syndrome. Six of the 7 patients (86%) who were tested for SCN1A mutations had positive results. The best treatment combinations included topiramate, valproate, or the ketogenic diet. Dravet syndrome is a well-defined epileptic syndrome that needs larger recognition, particularly because commercial testing for SCN1A gene mutations is now available in the United States. Despite its reputation for seizure intractability, several treatment options may be particularly helpful, whereas others need to be avoided.

Stiripentol

Stiripentol (STP) is a new antiepileptic compound made by Biocodex. It recently proved to increase the GABAergic transmission in vitro in an experimental model of immature rat. Clinical studies were based on the fact that STP also acts as an inhibitor of CYP3A4, CYP1A2, and CYP2C19 in vivo in epileptic patients. Whereas the studies in adult patients were disappointing, the trials conducted in pediatric populations demonstrated a specific efficacy of STP in severe myoclonic epilepsy in infancy, Dravet syndrome, when combined with valproate and clobazam. Based on these results, STP was granted orphan drug status in the European Union for the treatment of Dravet syndrome. The French experience in compassionate use suggests that STP might also be of benefit when combined with carbamazepine in pediatric patients with pharmacoresistant partial epilepsy. The interactions of STP with a large number of drugs need to be carefully taken into account, with doses of the combined antiepileptic drugs adjusted to improve the tolerability of the therapeutic association.

Stiripentol, a Putative Antiepileptic Drug, Enhances the Duration of Opening of GABAA-Receptor Channels

PURPOSE

Stiripentol (STP) is currently an efficient drug for add-on therapy in infantile epilepsies because it improves the efficacy of antiepileptic drugs (AEDs) through its potent inhibition of liver cytochromes P450. In addition, STP directly reduces seizures in several animal models of epilepsy, suggesting that it might also have anticonvulsive effects of its own. However, its underlying mechanisms of action are unknown.

METHODS

We examined the interactions of STP with gamma-aminobutyric acid (GABA) transmission by using patch-clamp methods in CA3 pyramidal neurons in the neonatal rat.

RESULTS

STP markedly increased miniature inhibitory postsynaptic current (mIPSC) decay-time constant in a concentration-dependent manner. The prolongation of mIPSC duration does not result from an interaction with GABA transporters because it persisted in the presence of GAT-1 inhibitors (SKF-89976A and NO-711). An interaction with benzodiazepine or neurosteroid binding sites also was excluded because STP-mediated increase of decay time was still observed when these sites were initially saturated (by clobazam, zolpidem, or pregnanolone) or blocked (by flumazenil or dehydroepiandrosterone sulfate), respectively. In contrast, saturating barbiturate sites with pentobarbital clearly occluded this effect of STP, suggesting that STP and barbiturates interact at the same locus. This was directly confirmed by using outside-out patches, because STP increased the duration and not the frequency of opening of GABAA channels.

CONCLUSIONS

At clinically relevant concentrations, STP enhances central GABA transmission through a barbiturate-like effect, suggesting that STP should possess an antiepileptic effect by itself.

In vitro and in vivo inhibitory effect of stiripentol on clobazam metabolism

A metabolic interaction between stiripentol (STP), an anticonvulsant agent that inhibits the activity of several cytochromes P450 (P450s), and clobazam (CLB), a 1,5-benzodiazepine, used in association with STP in severe myoclonic epilepsy in infancy was observed in vivo. This interaction was characterized in vitro using cDNA-expressed CYP3A4 and CYP2C19 (main P450 involved in CLB metabolism) to calculate K(i) and IC(50) of stiripentol in comparison with ketoconazole (CYP3A4 inhibitor) and omeprazole (CYP2C19 inhibitor). STP inhibited N-demethylation of CLB to N-desmethylclobazam (NCLB) mediated by CYP3A4 (noncompetitively) and CYP2C19 (competitively) with K(i) = 1.59 +/- 0.07 and 0.516 +/- 0.065 microM and IC(50) = 1.58 microM [95% confidence interval (CI95%) = 1.20-2.08] and 3.29 microM (CI95% = 1.87-5.79), respectively. STP inhibited also more strongly the 4'-hydroxylation of NCLB to 4'-hydroxy-N-desmethylclobazam by CYP2C19 [competitive interaction with K(i) = 0.139 +/- 0.025 microM and IC(50) = 0.276 microM (CI95% = 0.206-0.371)]. The inhibitory effect of STP on CLB demethylation by CYP3A4 was much weaker than that of ketoconazole [IC(50) = 0.023 microM (CI95% = 0.016-0.033)], whereas its effect on NCLB hydroxylation by CYP2C19 was much higher than that of omeprazole [IC(50) = 2.99 microM (CI95% = 2.11-4.24)]. The major in vitro inhibitory effect of STP on CLB metabolism and mostly on NCLB biotransformation is consistent with the changes in vivo in CLB and NCLB plasma concentrations in children treated by the association CLB/STP.

Stiripentol

Stiripentol (STP) is a new antiepileptic compound produced by Biocodex. It is not structurally related to any of the other currently marketed antiepileptic products as it belongs to the group of aromatic allylic alcohols. It has recently been proved to increase GABAergic transmission in experimental models. It has been studied and used in France and Canada for > 10 years, but its clinical development was delayed due to the inhibitory effect of STP on hepatic cytochrome P450 (CYP). Clinical studies were based on the fact that STP also acts as an inhibitor of CYP3A4, CYP1A2 and CYP2C19 in vivo in epileptic patients. Although the studies in adult patients were disappointing, the trials conducted in paediatric populations demonstrated a specific efficacy of STP in a severe form of early childhood epilepsy, Dravet syndrome (severe myoclonic epilepsy in infancy), when combined with valproate and clobazam. Based on these results, STP was granted orphan drug status in the European Union for the treatment of Dravet syndrome. The French experience in compassionate use suggests that STP might also be of benefit when combined with carbamazepine in paediatric patients with pharmacoresistant partial epilepsy. Nevertheless, two controlled adjunctive-therapy trials were recently completed in paediatric populations with epilepsy. The interactions of STP with a large number of drugs need to be carefully taken into account by adjusting the doses of the combined antiepileptic drugs in order to improve the tolerability of the therapeutic association.

Severe myoclonic epilepsy in infancy: toward an optimal treatment

Severe myoclonic epilepsy in infancy, or Dravet syndrome, is one of the catastrophic epilepsy syndromes. In the past, treatment was mainly based on valproate and phenobarbital. Recently, some of the new antiepilepsy drugs, such as topiramate and stiripentol, have been shown to be promising in the treatment of this epilepsy syndrome. The treatment regimen of 12 children with Dravet syndrome and proven mutations in the alpha subunit of the sodium channel SCN1A is reported here. Five patients on the "traditional" treatment regimen are compared with seven children on an "optimal" treatment regimen based on a combination of valproate and topiramate. With respect to the literature and our own experience, we propose guidelines for "optimal" treatment of children with severe myoclonic epilepsy in infancy. This includes prevention of hyperthermia, rigorous treatment of fever, avoiding stressful situations, maintenance treatment based on a combination of only two antiepilepsy drugs (ie, valproate and topiramate), and a strict acute seizure treatment based on benzodiazepines. To prevent long-lasting periods of status epilepticus, this acute seizure treatment must be taught to parents and caregivers.