Seizure Rescue Therapies: Comparing Approved and Commonly Used Benzodiazepine Formulations

A multicenter Phase II randomized, placebo-controlled single-blind trial with the SV2A ligand seletracetam in photosensitive epilepsy patients

The objective of this study was to evaluate the effect of seletracetam (SEL), a potent modulator of synaptic vesicle glycoprotein 2A (SV2A), in patients with photoparoxysmal EEG response (PPR) to intermittent photic stimulation (IPS) as proof-of-principle of efficacy in patients with epilepsy. In this multicenter, single-blind Phase II study, adults with photosensitive epilepsy, with/without concomitant antiseizure medication therapy, underwent IPS under 3 eye conditions (at eye closure, eyes closed and eyes open) after a single oral dose of placebo (day - 1) or SEL (day 1; 0.5, 1, 2, 4, 10, or 20 mg). Complete suppression was a standardized photosensitivity range reduction to 0 over ≥ 1 time points for all eye conditions. Partial suppression was a ≥ 3-point reduction over ≥ 3 testing times vs the same time points on day - 1 in ≥ 1 eye condition. In addition, pharmacokinetics and safety were assessed. Of 27 evaluable patients, 9 reentered to receive a 2nd dosing 1-6 months later, providing a total of 36 individual exposures. At all doses administered - even the lowest -, several subjects reached a complete abolishment of PPR, with a rapid onset of effect. Overall, complete abolishment of PPR was obtained in 40-71 % of the patients; the effect increasing with the dose. In terms of effective doses to suppress PPR, SEL was at least 1,500 times more potent than levetiracetam and 10-20 times more potent than brivaracetam. Adverse events of SEL, including dizziness and somnolence, were mild to moderate. Pharmacokinetics of SEL demonstrated rapid absorption and a linear dose:plasma level relationship. This proof-of-principle study demonstrates that - based on our own experience - SEL is the most potent compound ever tested in the photosensitivity model.

Evolution in the prescription and cost of non-intravenous rescue benzodiazepines for the treatment of seizure emergencies

OBJECTIVE

The proportion of patients with epilepsy who have a non-intravenous rescue benzodiazepine (non-IV-rBZD) available for seizure emergencies is unknown. This study aims to describe prescription patterns from 2006 to 2022, factors associated with prescription, and the impact of recently introduced intranasal benzodiazepines on prescription and cost.

METHODS

Retrospective analysis of the MarketScan Database, a claims database of privately insured patients in the United States.

RESULTS

Among 213 384 patients (53% female, median (p25-p75) age: 33 (17-50) years) with epilepsy taking long-term anti-seizure medications with follow-up of 2.62 (1.54-4.73) years, only 30 371 patients (14.2%) had at least one non-IV-rBZD prescription. The proportion of patients with at least one non-IV-rBZD prescription was higher among: (1) younger patients (61.4% in the 0-5 year age group, 44.2% in the 6-12 year age group, 23.9% in the 13-21 year age group, 4.8% in the 22-35 year age group, 1.8% in the 36-50 year age group, 1.3% in the 51-60 year age group, and 1.0% in the older than 60 years age group); (2) patients with refractory epilepsy (24.3% vs 10.9% in non-refractory epilepsy); and (3) patients with more emergency department visits or hospital admissions for epilepsy (7.1% among patients with 0, 19.2% among patients with 1-3, and 31.1% among patients with more than 3). Multivariate analysis confirmed young age, refractory epilepsy, and emergency department visits or hospitalizations for epilepsy as strong independent predictors of having at least one non-IV-rBZD prescription. Prescriptions for intranasal midazolam and intranasal diazepam have increased rapidly; they had moderately increased the overall proportion of patients with a non-IV-rBZD prescription, whereas the inflation-adjusted cost of non-IV-rBZDs has markedly increased.

SIGNIFICANCE

The vast majority of patients with epilepsy have not filled a prescription for non-IV-rBZDs. Seizure emergency readiness can be markedly improved, especially among adults. The cost of non-IV-rBZDs has increased with intranasal rescue medications.

Overview of acute seizure management in US nursing homes

INTRODUCTION

Residents in NH are more likely to be diagnosed with epilepsy or seizures, which are associated with higher mortality and complicate care. This setting provides unique challenges in the treatment of seizures however, little is known about current management practices in NH. Most studies in the literature concentrate on the use of antiseizure medications (ASMs) but little is known about the management of the acute seizure and clinical guidance is needed to ensure the safety of this vulnerable population. The objective of this study was to survey current practices, identifying knowledge deficits and inform future educational endeavors, including acute seizure action plans (ASAPs).

METHODS

A survey was developed pertaining to a broad spectrum of clinical aspects in the management of acute seizures in NH, distinguishing first time seizures from those in the setting of a known seizure disorder. It was sent to NH medical directors throughout the US and data was gathered from those who had at least one new case of new onset/epilepsy in the last 3 years.

RESULTS

Ninety-one NH directors responded with 52 % having a seizure protocol. Nurses are responsible in the majority of cases for protocol activation. Regardless of the patient's seizure history, rescue medications are given in the majority of cases, oral benzodiazepines, followed by intravenous and then rectal benzodiazepines. Newer intranasal and intramuscular formulations of benzodiazepines were less frequently prescribed. The most commonly prescribed ASM is levetiracetam, followed by lamotrigine, valproic acid and phenytoin. Staff training and in-service education occur infrequently. Respondents thought no-cost seizure education would be highly beneficial.

CONCLUSIONS AND IMPLICATIONS

Only approximately half of NH have protocols for the acute management of seizures. Rescue medications are given regardless of seizure history and often older ASMs are used for long-term management. Our study highlights areas of knowledge deficits and treatment areas for improvement, identifying the need and potential for ASAPs in NHs.

How astrocytic chloride modulates brain states

The way the central nervous system (CNS) responds to diverse stimuli is contingent upon the specific brain state of the individual, including sleep and wakefulness. Despite the wealth of readout parameters and data delineating the brain states, the primary mechanisms are yet to be identified. Here we highlight the role of astrocytes, with a specific emphasis on chloride (Cl-) homeostasis as a modulator of brain states. Neuronal activity is regulated by the concentration of ions that determine excitability. Astrocytes, as the CNS homeostatic cells, are recognised for their proficiency in maintaining dynamic homeostasis of ions, known as ionostasis. Nevertheless, the contribution of astrocyte-driven ionostasis to the genesis of brain states or their response to sleep-inducing pharmacological agents has been overlooked. Our objective is to underscore the significance of astrocytic Cl- homeostasis, elucidating how it may underlie the modulation of brain states. We endeavour to contribute to a comprehensive understanding of the interplay between astrocytes and brain states.