Safety and efficacy of midazolam nasal spray in the outpatient treatment of patients with seizure clusters: An open-label extension trial

Efficacy and Tolerability of Intranasal Midazolam Administration for Antiseizure Treatment in Adults: A Systematic Review

OBJECTIVE

The objective of this study was to assess the efficacy and tolerability of intranasal midazolam (in-MDZ) administration for antiseizure treatment in adults.

METHODS

Embase and Medline literature databases were searched. We included randomized trials and cohort studies (excluding case series) of adult patients (≥ 18 years of age) examining in-MDZ administration for epilepsy, epileptic seizures, or status epilepticus published in English between 1985 and 2022. Studies were screened for eligibility based on predefined criteria. The primary outcome was the efficacy of in-MDZ administration, and the secondary outcome was its tolerability. Extracted data included study design, patient characteristics, intervention details, and outcomes. Risk of bias was assessed using the Cochrane Risk of Bias Tool.

RESULTS

A total of 12 studies with 929 individuals treated with in-MDZ were included. Most studies were retrospective, with their number increasing over time. Administered in-MDZ doses ranged from 2.5 to 20 mg per single dose. The mean proportion of successful seizure termination after first in-MDZ administration was 72.7% (standard deviation [SD] 18%), and the proportion of seizure recurrence or persistent seizures ranged from 61 to 75%. Most frequent adverse reactions to in-MDZ were dizziness (mean 23.5% [SD 38.6%]), confusion (one study; 17.4%), local irritation (mean 16.6% [SD 9.6%]), and sedation (mean 12.7% [SD 9.7%]).

CONCLUSIONS

Administration of in-MDZ seems promising for the treatment of prolonged epileptic seizures and seizure clusters in adults. Limited evidence suggests that intranasal administration is safe. Further research is warranted because of the heterogeneity of cohorts, the variation in dosages, and the lack of uniformity in defining successful seizure termination.

Short-Term Impact of Seizures and Mitigation Opportunities

PURPOSE OF REVIEW

The burden of epilepsy is complex and consists of elements directly related to acute seizures as well as those associated with living with a chronic neurologic disorder. The purpose of this systematic review was to characterize short-term burdens of seizures and to explore the potential value of acute treatments to mitigate these burdens apart from reducing the risk of status epilepticus.

RECENT FINDINGS

A systematic literature search was conducted using PubMed to identify articles published from January 1, 2017, to June 22, 2023, that described short-term burdens and acute treatments of seizures. Primary outcomes included those related to short-term burdens of seizures and the benefits of acute treatments to reduce short-term burdens. Of the 1332 articles identified through PubMed and 17 through other sources, 27 had relevant outcomes and were included in the qualitative synthesis. Seizure emergencies negatively affected short-term quality of life and the ability to conduct normal daily living activities and were associated with physical (injury) and financial (emergency transport, hospitalization) burdens. The use of acute treatment was associated with a rapid return (≤ 1 h) to normal function/self for both patients and caregivers and potentially lower healthcare utilization and costs. Seizure action plans may improve knowledge and comfort with seizure care, empowering patients and caregivers. The short-term burden of seizures can create a substantial negative impact on patients and caregivers. Acute treatments may reduce the short-term burdens of seizures in addition to their well-described role to reduce seizure activity and the risk for status epilepticus.

Intracerebral electrographic activity following a single dose of diazepam nasal spray: A pilot study

OBJECTIVE

Rescue benzodiazepine medication can be used to treat seizure clusters, which are intermittent, stereotypic episodes of frequent seizure activity that are distinct from a patient's usual seizure pattern. The NeuroPace RNS® System is a device that detects abnormal electrographic activity through intracranial electrodes and administers electrical stimulation to control seizures. Reductions in electrographic activity over days to weeks have been associated with the longer-term efficacy of daily antiseizure medications (ASMs). In this pilot study, electrographic activity over hours to days was examined to assess the impact of a single dose of a proven rescue therapy (diazepam nasal spray) with a rapid onset of action.

METHODS

Adult volunteers (>18 years old) with clinically indicated RNS (stable settings and ASM usage) received a weight-based dose of diazepam nasal spray in the absence of a clinical seizure. Descriptive statistics for a number of detections and a sum of durations of detections at 10-min, hourly, and 24-h intervals during the 7-day (predose) baseline period were calculated. Post-dose detections at each time interval were compared with the respective baseline-detection intervals using a 1 SD threshold. The number of long episodes that occurred after dosing also were compared with the baseline.

RESULTS

Five participants were enrolled, and four completed the study; the excluded participant had recurrent seizures during the study. There were no consistent changes (difference >1 SD) in detections between post-dose and mean baseline values. Although variability was high (1 SD was often near or exceeded the mean), three participants showed possible trends for reductions in one or more electrographic variables following treatment.

SIGNIFICANCE

RNS-assessed electrographic detections and durations were not shown to be sensitive measures of short-term effects associated with a single dose of rescue medication in this small group of participants. The variability of detections may have masked a measurable drug effect.

PLAIN LANGUAGE SUMMARY

Rescue drugs are used to treat seizure clusters. Responsive neurostimulation (RNS) devices detect and record epilepsy brain waves and then send a pulse to help stop seizures. This pilot study looked at whether one dose of a rescue treatment changes brain activity detected by RNS. There was a very wide range of detections, which made it difficult to see if or how the drug changed brain activity. New studies should look at other types of brain activity, multiple doses, and larger patient groups.

Benzodiazepines for the Treatment of Seizure Clusters

Patients with epilepsy may experience seizure clusters, which are described by the US Food and Drug Administration (FDA) as intermittent, stereotypic episodes of frequent seizure activity that are distinct from a patient's usual seizure pattern. Untreated seizure clusters may increase the risk for status epilepticus, as well as decrease quality of life and increase burden on patients and care partners. Benzodiazepine therapies are the mainstay for acute treatment of seizure clusters and are often administered by nonmedical care partners outside a healthcare facility. Three rescue therapies are currently FDA-approved for this indication, with diazepam rectal gel being the first in 1997, for patients aged ≥  2 years. Limitations of rectal administration (e.g., positioning and disrobing the patient, which may affect ease of use and social acceptability; interpatient variation in bioavailability) led to the investigation of the potential for nasal administration as an alternative. Midazolam nasal spray (MDS) was approved by the FDA in 2019 for patients aged ≥  12 years and diazepam nasal spray (DNS) in 2020 for patients aged ≥  6 years; these two intranasal therapies have differences in their formulations [e.g., organic solvents (MDS) vs. Intravail and vitamin E for absorption and solubility (DNS)], effectiveness (e.g., proportion of seizure clusters requiring only one dose), and safety profiles. In clinical studies, the proportion of seizure clusters for which only one dose of medication was used varied between the three approved rescue therapies with the highest single-dose rate for any time period for DNS; however, although studies for all three preparations enrolled patients with highly intractable epilepsy, inclusion and exclusion criteria varied, so the three cannot be directly compared. Treatments that have been used off-label for seizure clusters in the USA include midazolam for injection as an intranasal spray (indicated for sedation/anxiolysis/amnesia and anesthesia) and tablet forms of clonazepam (indicated for treatment for seizure disorders) and lorazepam (indicated for anxiety). In the European Union, buccal and intranasal midazolam are used for treating the indication of prolonged, acute convulsive seizures and rectal diazepam solution for the indication of epileptic and febrile convulsions; duration of effectiveness for these medications for the treatment of seizure clusters has not been established. This paper examines the literature context for understanding seizure clusters and their treatment and provides effectiveness, safety, and administration details for the three FDA-approved rescue therapies. Additionally, other medications that are used for rescue therapy in the USA and globally are discussed. Finally, the potential benefits of seizure action plans and candidates for their use are addressed. This paper is intended to provide details about the unique characteristics of rescue therapies for seizure clusters to help clarify appropriate treatment for individual patients.

Opportunities for Community Pharmacists to Counsel Patients With Epilepsy and Seizure Clusters to Overcome Barriers and Foster Appropriate Treatment

Some patients with epilepsy experience seizure clusters, which may be defined as 2 or more seizures occurring within 24 hours. Left untreated, seizure clusters increase the risk for physical injury and may progress to status epilepticus, irreversible neurologic injury, and death. Rescue therapy is based on benzodiazepine treatment. Prompt, appropriate use should be specified in patients' individualized seizure action plans. Most seizure clusters occur outside the hospital setting. The ideal rescue therapy allows for easy and quick administration by a nonmedical person, which may minimize the need for intervention by emergency medical personnel or transportation to the hospital. In the 2 decades before the approval of 2 intranasal benzodiazepines in 2019 and 2020, rectal diazepam was the only route of administration approved by the US Food and Drug Administration specifically for seizure clusters. Each of the approved intranasal formulations has a unique profile. Both offer a convenient and socially acceptable route of administration. Recognition of seizure clusters and timing of proper administration are key to successful use of rescue therapy. Pharmacists' counseling plays an important role in reinforcing when and how to appropriately administer rescue therapies and the importance of consistently using rescue treatment when indicated to promote effective management. This review includes resources for pharmacists, patients, and caregivers; reviews currently available treatments; and discusses seizure action plans that support effective treatment of seizure clusters.

Practical Questions About Rescue Medications for Acute Treatment of Seizure Clusters in Children and Adolescents with Epilepsy in the USA: Expanding Treatment Options to Address Unmet Needs

Epilepsy is a common pediatric neurological condition, affecting approximately 470,000 children in the USA and having a prevalence of 0.9% in the global population of approximately 2.6 billion children. Epilepsy is associated with disruptions in several areas of a child's life, including medical burden, quality of life, cognitive outcomes, and higher risk of mortality. Additionally, some pediatric patients may experience acute seizure emergencies such as seizure clusters (also called acute repetitive seizures), which are intermittent increases in seizure activity that differ from the patient's usual seizure pattern and may occur despite daily antiseizure drug administration. Seizure clusters increase a patient's risk for status epilepticus and emergency room visits. Benzodiazepines are the main category of drugs used as acute seizure therapies for seizure clusters. This narrative review provides a practical discussion of care for pediatric patients with epilepsy and seizure clusters exploring such topics as details about the US Food and Drug Administration-approved acute seizure therapies, safety and ease of use of these medications, benefits of seizure action plans to help ensure optimal treatment, and considerations for transitioning a pediatric patient with acute seizure therapy to adult healthcare management.

The correlation of Esketamine with specific adverse events: a deep dive into the FAERS database

Analyzing the vast data from FAERS database to evaluate the association between Esketamine and specific adverse events to guide clinical practice and regulatory decisions. Data related to Esketamine adverse events from 2019 Q1 to 2023 Q1 were collected from FAERS database. After data standardization, various signal quantification technologies, such as ROR, PRR, BCPNN, and MGPS, were employed to identify and evaluate adverse reaction signals closely related to the use of Esketamine comprehensively. A total of 5061 reports with Esketamine as the primary suspected drug were obtained, identifying 117 adverse reaction terms (PT) involving 27 system organ class (SOC) categories. Apart from the adverse events already mentioned in the drug's instructions, this study identified some new, clinically valuable potential AE signals, such as Flashback, Tachyphylaxis, and Autoscopy. In addition, high-ranking results included euphoric mood, feeling of relaxation, and feeling drunk. Notably, the occurrence frequencies of suicidal ideation and suicide attempt were relatively high, so clinicians should be particularly vigilant about these potential adverse reactions when using Esketamine. Moreover, since this drug is administered as a nasal spray, issues such as drug monitoring procedure incorrectly performed and nasal discomfort may arise. This study underscores the potential adverse reactions and risks of Esketamine in clinical applications, especially regarding long-term efficacy, addiction risks, and suicidal risks.

Treatment of Seizure Clusters in Epilepsy: A Narrative Review on Rescue Therapies

Epilepsy is a common neurological disorder in the United States, affecting approximately 1.2% of the population. Some people with epilepsy may experience seizure clusters, which are acute repetitive seizures that differ from the person's usual seizure pattern. Seizure clusters are unpredictable, are emotionally burdensome to patients and caregivers (including care partners), and require prompt treatment to prevent progression to serious outcomes, including status epilepticus and associated morbidity (e.g., lacerations, fractures due to falls) and mortality. Rescue medications for community use can be administered to terminate a seizure cluster, and benzodiazepines are the cornerstone of rescue treatment. Despite the effectiveness of benzodiazepines and the importance of a rapid treatment approach, as many as 80% of adult patients do not use rescue medication to treat seizure clusters. This narrative review provides an update on rescue medications used for treatment of seizure clusters, with an emphasis on clinical development and study programs for diazepam rectal gel, midazolam nasal spray, and diazepam nasal spray. Results from long-term clinical trials have shown that treatments for seizure clusters are effective. Intranasal benzodiazepines provide ease of use and patient and caregiver satisfaction in pediatric and adult patients. Adverse events attributed to acute rescue treatments have been characterized as mild to moderate, and no reports of respiratory depression have been attributed to treatment in long-term safety studies. The implementation of an acute seizure action plan to facilitate optimal use of rescue medications provides an opportunity for improved management of seizure clusters, allowing those affected to resume normal daily activities more quickly.

Acute seizure therapies in people with epilepsy: Fact or fiction? A U.S. Perspective

Patients with epilepsy (PWE) may experience seizure emergencies including acute repetitive seizures despite chronic treatment with daily antiseizure medications. Seizures may adversely impact routine daily activities and/or healthcare utilization and may impair the quality of life of patients with epilepsy and their caregivers. Seizures often occur at home, school, or work in a community setting. Appropriate treatment that is readily accessible for patients with seizure urgencies and emergencies is essential outside the hospital setting. When determining the best acute antiseizure therapy for PWE, clinicians need to consider all of the available rescue medications and their routes of administration including the safety and efficacy profiles. Benzodiazepines are a standard of care as a rescue therapy, yet there are several misconceptions about their use and safety. Reevaluating potential misconceptions and formulating best practices are necessary to maximize usage for each available option of acute therapy. We examine common beliefs associated with traditional use of acute seizure therapies to refute or support them based on the current level of evidence in the published literature.

Acute Abortive Therapies for Seizure Clusters in Long-Term Care

OBJECTIVES

To describe acute seizure treatment for the long-term care setting, emphasizing rescue (acute abortive) medications for on-site management of acute unexpected seizures and seizure clusters.

DESIGN

Narrative review.

SETTING AND PARTICIPANTS

People with seizures in long-term care, including group residences.

METHODS

PubMed was searched using keywords that pertained to rescue medications, seizure emergencies/epilepsy, seizure action plans, and long-term care.

RESULTS

Seizure disorder, including epilepsy, is prevalent in long-term care residences, and rescue medications can be used for on-site treatment. Diazepam rectal gel, intranasal midazolam, and diazepam nasal spray are US Food and Drug Administration (FDA)-approved seizure-cluster rescue medications, and intravenous diazepam and lorazepam are approved for status epilepticus. Benzodiazepines differ by formulation, route of administration, absorption, and metabolism. Intranasal formulations are easy and ideal for public use and when rectal treatment is challenging (eg, wheelchair). Intranasal, intrabuccal, and rectal formulations do not require specialized training to administer and are easier for staff at all levels of training compared with intravenous treatment. Off-label rescue medications may have anecdotal support; however, potential disadvantages include variable absorption and onset of action as well as potential risks to patients and caregivers/care partners. Delivery of intravenous-administered rescue medications is delayed by the time needed to set up and deliver the medication and is subject to dosing errors. Seizure action plans that include management of acute seizures can optimize the quality and timing of treatment, which may reduce emergency service needs and prevent progression to status epilepticus.

CONCLUSIONS AND IMPLICATIONS

Seizure disorder is prevalent across all ages but is increased in older adults and in those with intellectual and developmental disabilities. Prompt intervention may reduce negative outcomes associated with acute unexpected seizures and seizure clusters. Seizure action plans that include acute seizures can improve the treatment response by detailing the necessary information for staff to provide immediate treatment.

Overcoming barriers to the management of seizure clusters: ease of use and time to administration of rescue medications

INTRODUCTION

Patients with epilepsy can experience seizure clusters (acute repetitive seizures), defined as intermittent, stereotypic episodes of frequent seizure activity that are distinct from typical seizure patterns. There are three FDA-approved rescue medications, diazepam rectal gel, midazolam nasal spray, and diazepam nasal spray, that can be administered to abort a seizure cluster in a nonmedical, community setting. Despite their effectiveness and safety, rescue medications are underutilized, and patient/caregiver experiences and perceptions of ease of use may constitute a substantial barrier to greater utilization.

AREAS COVERED

The literature on rescue medications for seizure clusters is reviewed, including the effectiveness and safety, with an emphasis on ease and timing of treatment and associated outcomes. Barriers to greater utilization of rescue medication and the role of seizure action plans are discussed.

EXPERT OPINION

Intranasal rescue medications are easier to use and can be administered more rapidly than other routes (rectal, intravenous). Importantly, rapid administration of intranasal rescue medications has been associated with shorter durations of seizure activity as compared with rectal/intravenous routes. Intranasal rescue medications are also easy to use and socially acceptable. These factors potentially remove or reduce barriers to use and optimize the management of seizure clusters.

The Evaluation of the Efficacy and Safety of Midazolam Nasal Spray in Patients With Seizure Clusters: A Systematic Review and Meta-Analysis

Midazolam nasal spray (MDZ-NS) is a new emerging rescue medication that suppresses epileptic seizures. Until now, few studies, pharmacokinetic (PK) and pharmacodynamic (PD) profiles, and clinical trials have shown that midazolam nasal spray could become an effective and promising alternative to conventional routes (intravenous {IV}/rectal). Therefore, we thought of conducting a systematic review and meta-analysis of midazolam (MDZ) to assess its potential outcomes. The analysis was also evaluated based on the pharmacokinetic (PK) and pharmacodynamic (PD) profiles of midazolam nasal spray. A systematic literature search was carried out through various databases to identify studies of accounted outcomes of midazolam nasal spray (MDZ-NS). Randomized and other studies of patients (12 years or older) with seizure clusters (SCs) were included. A total of three full-text articles were considered for systematic review and meta-analysis as per the inclusion and exclusion criteria. The 5 mg MDZ-NS was observed to be equally safe as a placebo, and the risk ratio (RR) was 1.01 (95% confidence interval (CI): 0.67-1.53). After the administration of MDZ-NS, either the patients remained seizure-free for six hours or more or the seizure was terminated within 10 minutes and had no recurrence between 10 minutes and six hours. The risk ratio (RR) obtained was 1.54 (95% CI: 1.25-1.91). The result was statistically significant as a higher success rate was observed with the use of 5 mg midazolam nasal spray compared to placebo (p < 0.0001). Heterogeneity was not observed in the results of the included studies (inconsistency index {I²}: 0%). The present systematic review and meta-analysis demonstrated that 5 mg midazolam nasal spray was efficacious in treating patients with seizure clusters and is well-tolerated. Also, its use is relatively safe.

Psychosocial outcomes of repeated treatment of seizure clusters with midazolam nasal spray: Results of a phase 3, open-label extension trial

OBJECTIVE

To evaluate treatment satisfaction, level of anxiety, confidence about traveling with midazolam nasal spray (MDZ-NS), and health-related quality of life in patients with seizure clusters and their caregivers after repeated, intermittent use of MDZ-NS in the outpatient setting.

METHODS

We analyzed the psychosocial outcome data from a phase 3, open-label extension trial (ARTEMIS-2; P261-402; NCT01529034) in patients 12 years of age and older with seizure clusters on a stable regimen of antiseizure medications. Caregivers administered MDZ-NS 5 mg when patients experienced a seizure cluster. A second dose could be given if seizures did not terminate within 10 min or recurred from 10 min to 6 h. Treatment Satisfaction Questionnaire for Medication (TSQM), the Intranasal Therapy Impact Questionnaire (ITIQ), and the Short Form-12 Health Survey version 2 (SF-12v2) were self-administered by patients and/or caregivers at prespecified visits.

RESULTS

Of the one hundred and seventy-five patients enrolled in ARTEMIS-2, 161 (92.0%) received ≥ 1 dose of MDZ-NS and had a post-treatment seizure-related assessment and were included in the Efficacy Evaluable Set in this analysis, with a total of 1,998 treated seizure clusters over a median duration of 16.8 months. All TSQM scales showed improvement from the baseline of the double-blind ARTEMIS-1 trial (NCT01390220) to the last visit in ARTEMIS-2, indicating greater satisfaction with MDZ-NS across all domains, with a mean change from baseline of 8.8, 6.1, 4.3, and 6.2 for effectiveness (n = 135), side effects (n = 139), convenience (n = 139), and global satisfaction (n = 138), respectively. Change from baseline in TSQM scores generally increased with repeated MDZ-NS use. In both patients and caregivers, anxiety generally lessened with repeated MDZ-NS use, with a mean improvement in ITIQ scores in patients' anxiety since receiving MDZ-NS from 2.5 (n = 138) to 3.5 (n = 145) from visit 1 to the last visit (and from 2.6 [n = 156] to 3.6 [n = 160] for caregivers), respectively. From visit 1 (screening and enrollment in ARTEMIS-2) to visit 10 (after 16 seizure cluster episodes treated with MDZ-NS), the proportions of patients and caregivers who answered "strongly agree" or "agree" for confidence about traveling with an intranasal spray remained ≥ 79% and generally increased over repeated MDZ-NS use. Small positive mean changes in SF-12v2 scores from baseline to the last visit were observed in both patients and caregivers, respectively, for the domains of physical functioning (0.9, 1.1), role-physical (2.4, 0.3), bodily pain (1.7, 0.3), general health (0.6, 1.2), and role-emotional (2.1, 0.3), and in the physical health component (1.6, 1.0).

CONCLUSION

Patients and caregivers perceived MDZ-NS favorably, with improvement from baseline on perceived effectiveness, side effects, convenience, and global satisfaction in the TSQM. This is supported by progressively lower anxiety and higher confidence levels about traveling with MDZ-NS over repeated intermittent use in the ITIQ. The positive mean changes observed in SF-12v2 scores from baseline to the last visit were small in magnitude. Limitations of this exploratory analysis include the open-label trial design and that these questionnaires have not been directly validated in epilepsy to identify clinically important changes; however, this does not mean these findings are not clinically meaningful. Overall, MDZ-NS is a socially acceptable drug device for outpatient treatment of seizure clusters that has the potential to improve quality of life and overall independence.

The nose has it: Opportunities and challenges for intranasal drug administration for neurologic conditions including seizure clusters

Nasal administration of treatments for neurologic conditions, including rescue therapies to treat seizure clusters among people with epilepsy, represents a meaningful advance in patient care. Nasal anatomy and physiology underpin the multiple advantages of nasal administration but also present challenges that must be addressed in any successful nasal formulation. Nasal cavity anatomy is complex, with a modest surface area for absorption that limits the dose volume of an intranasal formulation. The mucociliary clearance mechanism and natural barriers of the nasal epithelia must be overcome for adequate absorption. An extensive vasculature and the presence of olfactory nerves in the nasal cavity enable both systemic and direct-to-brain delivery of drugs targeting the central nervous system. Two intranasal benzodiazepine rescue therapies have been approved by the US Food and Drug Administration for seizure-cluster treatment, in addition to the traditional rectal formulation. Nasal sprays are easy to use and offer the potential for quick and consistent bioavailability. This review aims to increase the clinician's understanding of nasal anatomy and physiology and of the formulation of intranasal rescue therapies and to facilitate patient education and incorporate intranasal rescue therapies for seizure clusters (also known as acute repetitive seizures) into their seizure action plans.

Rescue therapies for seizure clusters: Pharmacology and target of treatments

The primary goal of treatment for seizure clusters is cessation of the cluster to avoid progression to more severe conditions, such as prolonged seizures and status epilepticus. Rescue therapies are key components of treatment plans for patients with seizure clusters. Three rescue therapies are approved in the United States for the treatment of seizure clusters: diazepam rectal gel, midazolam nasal spray, and diazepam nasal spray. This review characterizes the pharmacological function of rescue therapies for seizure clusters, as well as describing γ‐aminobutyric acid A (GABA_A) receptor functions. GABA_A receptors are heteropentamers, consisting primarily of α1‐6, β1‐3, γ2, and δ subunits in the central nervous system. These subunits can traffic to and from the membrane to regulate membrane potential. Benzodiazepines, such as diazepam and midazolam, are positive allosteric modulators of GABA_A receptors, the activation of which leads to an increase in intracellular chloride, hyperpolarization of the cell membrane, and a reduction in excitation. GABA_A receptor subunit mutations, dysregulation of trafficking, and degradation are associated with epilepsy. Although benzodiazepines are effective GABA_A receptor modulators, individual formulations have unique profiles in practice. Diazepam rectal gel is an effective rescue therapy for seizure clusters; however, adults and adolescents may have social reservations regarding its administration. Intranasal delivery of midazolam or diazepam is a promising alternative to rectal administration because these formulations offer easy, socially acceptable administration and exhibit a rapid onset. Off‐label benzodiazepines, such as orally disintegrating lorazepam and intranasal use of an intravenous formulation of midazolam via nasal atomizer, are less well characterized regarding bioavailability and tolerability compared with approved agents.

Economic aspects of treating seizure clusters

Seizure clusters may initiate a chain of events that have economic as well as clinical consequences. The potential economic consequences of seizure clusters must be weighed against the cost of medication to attenuate them. This is true both for individual patients and for society. Data needed for economic analyses include the chance that a cluster will progress to an adverse outcome, such as a need for emergency care, the costs of such an outcome, the cost of a rescue medication (RM), and the effectiveness of the RM. Indirect costs, such as lost employment for patients and caregivers, must also be considered. Several types of economic analyses can be used to determine costs and benefits of a medical intervention. There are studies comparing different RMs from an economic perspective, but there is little direct information on the costs of using an RM versus allowing clusters to run their course. However, the high expense of consequences of seizure clusters makes it likely that effective RMs will make economic as well as medical sense for many patients.

Recognizing seizure clusters in the community: The path to uniformity and individualization in nomenclature and definition

Seizure emergencies experienced by patients with epilepsy include status epilepticus and seizure clusters. Although an accepted definition of status epilepticus exists, no clear consensus definition of seizure clusters has emerged; this is further complicated by the appearance in the literature of various empirically based definitions that have been developed for clinical trial study designs. In general, patients with intractable epilepsy have been shown to have a significant risk for acute episodes of increased seizure activity called seizure clusters (also referred to as acute repetitive seizures, among other terms) that differ from their usual seizure pattern. Duration (e.g., number of hours or days) is often included in the definition of a seizure cluster; however, the duration may vary among patients, with some seizure clusters lasting ≥24 h and requiring long-acting treatment for this period. In addition to seizure cluster duration, the time between seizures and possible acceleration in seizure frequency during the cluster may be important variables. The recognition and treatment of seizure clusters require urgent action because episodes that are not quickly and appropriately treated may lead to injury or progress to status epilepticus or potentially death. Most seizure clusters occur outside a medical facility (in the community) and treatment is usually administered by nonmedical individuals; therefore, health care providers may benefit from a clear description of these potential seizure emergencies that they can then use to educate patients and caregivers on the prompt and appropriate identification of seizure clusters and administration of rescue therapy. Here we explore why greater uniformity is needed in the discussion of seizure clusters. This exploration examines epidemiologic studies of seizure clusters and status epilepticus, inconsistencies in nomenclature and definitions for seizure clusters, practical application of seizure cluster terminology, and the potential use of acute seizure action plans and patient-specific individualized definitions in the clinical setting.

Updated review of rescue treatments for seizure clusters and prolonged seizures

INTRODUCTION

Although the treatment of epilepsy primarily focuses on prevention, recurrent seizures are unfortunately an ongoing reality, particularly in people with epilepsy who live with chronic refractory seizures. Rescue medications are agents which can be administered in urgent/emergent seizure episodes such as seizure clusters or prolonged seizures with the goal of terminating seizure activity, preventing morbidity, and decreasing the risk of further seizures.

AREAS COVERED

This review first discusses clinical opportunities for rescue medications, with particular attention focused on seizure clusters and prolonged seizures, including their epidemiology, risk factors, and associated morbidity. Current rescue medications, their indications, efficacy, and adverse effects are discussed. We then discuss rescue medications and formulations which are currently under development, concentrating on practical aspects relevant for clinical care.

EXPERT OPINION

Rescue medications should be considered for all people with epilepsy with ongoing seizures. Recent rescue medications including intranasal formulations provide considerable advantages. New rescue medications are being developed which may expand opportunities for effective treatment. In the future, combining rescue medications with seizure detection and seizure prediction technologies should further expand opportunities for use and should reduce the morbidity of seizures and provide increased comfort, control, and quality of life for people living with epilepsy.

Rescue therapies in epilepsy

PURPOSE OF REVIEW

The purpose of this review is to provide a succinct evaluation of the current rescue medications and action plans available to our patients with seizure clusters in the outpatient setting.

RECENT FINDINGS

The main themes of the recent findings are that rescue medications and seizure action plans (SAPs) are underutilized, particularly in the adult population. The safety and efficacy of intranasal midazolam and intranasal diazepam is comparable with rectal diazepam for the treatment of seizure clusters. Additionally, this intranasal formulation has the benefit of a more socially acceptable route of administration and ease of use.

SUMMARY

The implication of these findings is a greater variety and awareness in the rescue medications available to our patients suffering from seizure clusters.

Benzodiazepines in the Management of Seizures and Status Epilepticus: A Review of Routes of Delivery, Pharmacokinetics, Efficacy, and Tolerability

Status epilepticus (SE) is an acute, life-threatening medical condition that requires immediate, effective therapy. Therefore, the acute care of prolonged seizures and SE is a constant challenge for healthcare professionals, in both the pre-hospital and the in-hospital settings. Benzodiazepines (BZDs) are the first-line treatment for SE worldwide due to their efficacy, tolerability, and rapid onset of action. Although all BZDs act as allosteric modulators at the inhibitory gamma-aminobutyric acid (GABA)_A receptor, the individual agents have different efficacy profiles and pharmacokinetic and pharmacodynamic properties, some of which differ significantly. The conventional BZDs clonazepam, diazepam, lorazepam and midazolam differ mainly in their durations of action and available routes of administration. In addition to the common intravenous, intramuscular and rectal administrations that have long been established in the acute treatment of SE, other administration routes for BZDs-such as intranasal administration-have been developed in recent years, with some preparations already commercially available. Most recently, the intrapulmonary administration of BZDs via an inhaler has been investigated. This narrative review provides an overview of the current knowledge on the efficacy and tolerability of different BZDs, with a focus on different routes of administration and therapeutic specificities for different patient groups, and offers an outlook on potential future drug developments for the treatment of prolonged seizures and SE.

Implications of Seizure-Cluster Treatment on Healthcare Utilization: Use of Approved Rescue Medications

PURPOSE

People with epilepsy may experience seizure clusters despite a stable regimen of antiseizure medications. Such clusters have the potential to last ≥24 hours, typically occur in the community setting, and may progress to medical emergencies, such as status epilepticus, if untreated. Thus, long-acting rescue therapy for seizure clusters is needed that can be administered by nonmedical individuals outside a hospital. Benzodiazepines are the foundation of rescue therapy for seizure clusters. The approved outpatient treatments (ie, diazepam, midazolam) have differing profiles that may affect multiple aspects of health-care utilization. The current labeling of these medications allows for a second dose if needed to control the cluster. Although no head-to-head studies directly comparing rescue treatments have been conducted, differences between studies with generally similar designs may provide context for the potential importance of second doses of rescue therapy on health-care utilization.

METHODS

For this analysis, large, long-term, open-label studies of approved seizure-cluster treatments designed for use by nonmedical caregivers were reviewed, and the percentage of seizure clusters for which a second dose was used or that were not controlled at 6, 12, and 24 hours was examined. Available data on hospitalizations were also collected.

RESULTS

The 3 identified studies meeting the inclusion criteria were for use of diazepam rectal gel, intranasal midazolam, and diazepam nasal spray. Across these studies, the use of a second dose ranged from <40% at 6 hours to <13% at 24 hours. Hospitalizations and serious treatment-emergent adverse events were reported variably across these studies.

CONCLUSION

These results demonstrate the importance of second doses of rescue therapy for seizure clusters for optimizing health-care utilization. Need for second doses should be included as one component. In turn, when second doses are needed, they have the potential to curtail emergency department use and hospitalization and to prevent further seizure clusters.

Lack of observed tolerance to diazepam nasal spray (Valtoco®) after long-term rescue therapy in patients with epilepsy: Interim results from a phase 3, open-label, repeat-dose safety study

OBJECTIVE

Tolerance is a known consideration for maintenance use of benzodiazepines and other antiseizure drugs; however, clinical experience suggests that tolerance may not be anticipated with long-term intermittent use of benzodiazepines as rescue therapy. Diazepam nasal spray (Valtoco®) is a proprietary intranasal formulation approved for the acute treatment of intermittent, stereotypic episodes of frequent seizure activity (ie, seizure clusters, acute repetitive seizures) in patients with epilepsy aged ≥6 years. Reported here are exploratory analyses investigating whether there was evidence of development of tolerance in an interim analysis of a long-term, phase 3, open-label safety study of diazepam nasal spray.

METHODS

Patients and care partners were trained to administer 5, 10, 15, or 20 mg of diazepam nasal spray (age- and weight-based dosing), with a second dose administered 4-12 hours later if needed. A series of analyses were performed to assess evidence of tolerance using 2 equal, adjacent time periods and data for each patient to compare the proportion of events for which second doses of diazepam nasal spray (as a proxy for effectiveness) were administered in period 1 compared with period 2.

RESULTS

A total of 175 patients were enrolled at interim cutoff, and 158 were treated with diazepam nasal spray for 3370 seizure-cluster events. For 73.4% of patients, duration of exposure to diazepam nasal spray was ≥12 months. A total of 191 analyses were conducted; the proportion of analyses in which second doses in period 2 were lower than in period 1 was 72.8%. Only 5 analyses showed nominally statistically significant changes (P < 0.05); this is fewer than expected by chance, and these differences were not directionally consistent. There was no safety signal with continued use.

CONCLUSIONS

These analyses found no statistical evidence of tolerance with the use of diazepam nasal spray over time based on use of a second dose in an initial period of the study compared with a subsequent period for each patient. These results are in agreement with prior studies of benzodiazepine rescue therapy.

Evaluation of diazepam nasal spray in patients with epilepsy concomitantly using maintenance benzodiazepines: An interim subgroup analysis from a phase 3, long-term, open-label safety study

Objective

Diazepam nasal spray (Valtoco), indicated for acute treatment of frequent seizure activity (seizure clusters) in patients with epilepsy ≥6 years of age, is designed to be a rapid, noninvasive, socially acceptable route of administration. This interim analysis evaluated the safety profile of diazepam nasal spray in patients with and without concomitant use of benzodiazepines, with use of a second dose for a seizure cluster as a proxy for effectiveness.

Methods

A long‐term, phase 3, open‐label safety study enrolled patients with epilepsy who had seizures despite a stable antiseizure medication regimen.

Results

Among 175 patients enrolled by October 31, 2019, a total of 158 were treated with diazepam nasal spray (aged 6–65 years; 53.8% female). Of those, 119 (75.3%) received concomitant benzodiazepines (60, chronic; 59, intermittent); 39 (24.7%) did not. Use of a second dose was similar in patients using chronic concomitant benzodiazepines (second dose in 11.1% [144/1299]) and those with no concomitant benzodiazepines (second dose in 10.3% [41/398]). Treatment emergent adverse events (TEAEs) occurred for 80.0% with chronic use of concomitant benzodiazepines and 61.5% without. Cardiorespiratory depression was not reported, and no serious TEAEs were treatment related. Study retention was high: 83.3% in the chronic benzodiazepine group and 76.9% in the no‐benzodiazepine group. Findings were similar in a sub‐analysis of patients who were (n = 44) or were not (n = 75) taking clobazam.

Significance

This analysis of patients from a long‐term study shows a similar safety profile of diazepam nasal spray in patients with and without concomitant benzodiazepines, and consistent with the established profile for diazepam. Use of a single dose of diazepam nasal spray and high study retention rates suggest the effectiveness of diazepam nasal spray in patients irrespective of chronic daily benzodiazepine use. Results were similar in the clobazam sub‐analysis. These results support the safety and effectiveness of diazepam nasal spray in patients with concomitant benzodiazepine use.

Time Is Brain: Acute Control of Repetitive Seizures and Status Epilepticus Using Alternative Routes of Administration of Benzodiazepines

Time plays a major role in seizure evaluation and treatment. Acute repetitive seizures and status epilepticus are medical emergencies that require immediate assessment and treatment for optimal therapeutic response. Benzodiazepines are considered the first-line agent for rapid seizure control. Thus, various routes of administration of benzodiazepines have been studied to facilitate a quick, effective, and easy therapy administration. Choosing the right agent may vary based on the drug and route properties, patient’s environment, caregiver’s skills, and drug accessibility. The pharmacokinetic and pharmacodynamic aspects of benzodiazepines are essential in the decision-making process. Ultimately, agents and routes that give the highest bioavailability, fastest absorption, and a modest duration are preferred. In the outpatient setting, intranasal and buccal routes appear to be equally effective and more rapidly administered than rectal diazepam. On the other hand, in the inpatient setting, if available, the IV route is ideal for benzodiazepine administration to avoid any potential absorption delay. In this article, we will provide an overview and comparison of the various routes of benzodiazepine administration for acute control of repetitive seizures and status epilepticus.

A critical evaluation of midazolam nasal spray for the treatment of patients with seizure clusters

Introduction: Patients with epilepsy may experience seizure clusters (SCs), which are considered a medical emergency requiring immediate treatment. Besides seizures and seizure-related injuries, patients with SCs experience impaired quality of life and have a greater need for healthcare resources. Midazolam nasal spray (MDZ-NS) was approved by the United States Food and Drug Administration (FDA) for the treatment of SCs in 2019, and was the first FDA-approved nasally administered formulation for treating SCs.Areas covered: This article provides a critical evaluation of MDZ-NS for the treatment of patients with SCs. It covers the chemistry, pharmacodynamic and pharmacokinetic properties of MDZ-NS, and safety, tolerability, and efficacy data from phase I and phase III trials. SC treatment guidelines in different countries and for alternative therapies are also discussed.Expert opinion: Midazolam is a well-established drug that is familiar to physicians. The newer MDZ-NS formulation offers the benefits of intranasal administration, which allows for outpatient treatment by caregivers and other non-healthcare professionals when an SC occurs, and may be particularly meaningful to patients with limited treatment options because other routes of administration are unsuitable. MDZ-NS is effective and patients are known to return to baseline alertness and psychomotor function within 240 minutes after administration.

Overcoming the challenges of developing an intranasal diazepam rescue therapy for the treatment of seizure clusters

Seizure clusters must be treated quickly and effectively to prevent progression to prolonged seizures and status epilepticus. Rescue therapy for seizure clusters has focused on the use of benzodiazepines. Although intravenous benzodiazepine administration is the primary route in hospitals and emergency departments, seizure clusters typically occur in out‐of‐hospital settings, where a more portable product that can be easily administered by nonmedical caregivers is needed. Thus, other methods of administration have been examined, including rectal, intranasal, intramuscular, and buccal routes. Following US Food and Drug Administration (FDA) approval in 1997, rectal diazepam became the mainstay of out‐of‐hospital treatment for seizure clusters in the United States. However, social acceptability and consistent bioavailability present limitations. Intranasal formulations have potential advantages for rescue therapies, including ease of administration and faster onset of action. A midazolam nasal spray was approved by the FDA in 2019 for patients aged 12 years or older. In early 2020, the FDA approved a diazepam nasal spray for patients aged 6 years or older, which has a different formulation than the midazolam nasal product and enhances aspects of bioavailability. Benzodiazepines, including diazepam, present significant challenges in developing a suitable intranasal formulation. Diazepam nasal spray contains dodecyl maltoside (DDM) as an absorption enhancer and vitamin E to increase solubility in an easy‐to‐use portable device. In a Phase 1 study, absolute bioavailability of the diazepam nasal spray was 97% compared with intravenous diazepam. Subsequently, the nasal spray demonstrated less variability in bioavailability than rectal gel (percentage of geometric coefficient of variation of area under the curve = 42%–66% for diazepam nasal spray compared with 87%–172% for rectal gel). The diazepam nasal spray safety profile is consistent with that expected for rectal diazepam, with low rates of nasal discomfort (≤6%). To further improve the efficacy of rescue therapy, investigation of novel intranasal benzodiazepine formulations is underway.

Safety and efficacy of midazolam nasal spray for the treatment of intermittent bouts of increased seizure activity in the epilepsy monitoring unit: A double-blind, randomized, placebo-controlled trial

OBJECTIVE

Midazolam nasal spray (MDZ-NS) is indicated for acute treatment of intermittent, stereotypic episodes of frequent seizure activity (ie, seizure clusters, acute repetitive seizures) that are distinct from a patient's usual seizure pattern, in patients 12 years of age and older with epilepsy. This trial evaluated safety and efficacy of MDZ-NS in patients with epilepsy who were admitted to the epilepsy monitoring unit for seizure characterization/presurgical evaluation.

METHODS

In this randomized, double-blind, placebo-controlled phase 3 trial (P261-301; NCT01999777), eligible patients with ≥2 seizures in the 6-hour window preceding trial medication administration for whom treatment was appropriate based on investigator's judgment were randomized (1:1) to MDZ-NS 5 mg or placebo. Efficacy outcomes were proportion of patients seizure-free for 6 hours after treatment and time to first seizure within 6 hours. Safety and tolerability outcomes included treatment-emergent adverse events (TEAEs).

RESULTS

Sixty-two patients were randomized (MDZ-NS n = 31; placebo n = 31), received trial medication, and completed the trial. A higher proportion of patients on MDZ-NS than placebo were seizure-free for 6 hours following treatment (54.8% vs 38.7%); however, the 16.1% difference was not statistically significant (P = .1972). The Kaplan-Meier curve of time to first seizure showed separation of both groups in favor of MDZ-NS from ~1.5 hours post-dose and throughout the 6-hour Treatment phase. Median time to first seizure was not estimable for MDZ-NS (>50% of patients had no seizure) and 3.9 hours for placebo (P = .1388). TEAEs with MDZ-NS were generally comparable to those with placebo. There were no deaths, serious TEAEs, or discontinuations due to TEAEs.

SIGNIFICANCE

Although the observed treatment difference may be clinically meaningful, statistical significance was not demonstrated. Results suggest that MDZ-NS 5 mg may provide improvement over placebo, with efficacy maintained for ≥6 hours post-dose. MDZ-NS was well tolerated in this population.

Using quality improvement to implement the CNS/AAN quality measure on rescue medication for seizures

OBJECTIVE

A multidisciplinary quality improvement (QI) team was established to conduct analysis of data for prescribed seizure rescue medication doses from January 2013 to December 2015 to identify and improve inappropriately low dose prescriptions. The QI team identified areas of focus for improvement opportunities and developed the project objective based on the 2017 American Academy of Neurology (AAN) and Child Neurology Society (CNS) quality measure.

METHODS

Within a freestanding children's hospital, the QI team developed key drivers and implemented interventions, such as the midazolam prefilled syringe program with use of standardized dosing, electronic chart tools, monthly pharmacy review of all underdosed prescriptions, and provider and nursing education. The team created an automated monthly report to monitor prescribed seizure rescue medication dosing compliance. The year 2015 was used as the preliminary data baseline period with an average noncompliance rate of 3.5%.

RESULTS

From January 2016 to December 2019, the team has decreased and sustained the noncompliance rate to an average of 0.38%. The data for the project included 12,975 seizure rescue medication prescribed by a neurology provider from January 2015 to December 2019. Compliance with properly dosed diazepam orders continues to be the largest area of opportunity. The data demonstrated a centerline shift in January 2019, moving the baseline average of 7.2% noncompliance to the current average rate of 0.22%. In comparison, underdosed midazolam orders occurred at an average rate of 0.037% in the same timeframe.

SIGNIFICANCE

Using quality improvement methodologies, the team successfully and substantially decreased provider prescribed and signed underdosed rescue medication orders by an average of 89%. This QI project demonstrates successful implementation and improvement addressing the AAN/CNS quality measure of proper rescue seizure treatment dosing.

The Nose Knows: Intranasal Midazolam To Treat Acute Seizures During Inpatient Epilepsy Monitoring

Efficacy, Tolerability, and Safety of Concentrated Intranasal Midazolam Spray as Emergency Medication in Epilepsy Patients During Video-EEG Monitoring

von Blomberg A, Kay L, Knake S, Fuest S, Zöllner JP, Reif PS, Herrmann E, Balaban Ü, Schubert-Bast S, Rosenow F, Strzelczyk A. CNS Drugs. 2020;34(5):545-553. doi: 10.1007/s40263-020-00720-w

Background:

An efficient, well tolerated, and safe emergency treatment with a rapid onset of action is needed to prevent seizure clusters and to terminate prolonged seizures and status epilepticus. Objectives: This study aimed to examine the efficacy, tolerability, and safety of intranasal midazolam (in-MDZ) spray in clinical practice.

Methods:

In this retrospective, multicenter observational study, we evaluated all patients with peri-ictal application of in-MDZ during video-electroencephalography (EEG) monitoring at the epilepsy centers in Frankfurt and Marburg between 2 014 and 2017. For every patient, we analyzed the recurrence of any seizure or generalized tonic-clonic seizures after index seizures with and without in-MDZ administration. Treatment-emergent adverse events were also evaluated.

Results:

Intranasal MDZ was used in 243 patients with epilepsy (mean age 35.5 years; range 5-76 years; 46.5% female) for treatment of 459 seizures. A median dose of in-MDZ 5 mg (ie, 2 puffs; range 2.5-15 mg) was administered within a median time from EEG seizure onset until in-MDZ application of 1.18 minutes (interquartile range [IQR] 1.27), while median time from clinical seizure onset until in-MDZ administration was 1.08 minutes (IQR 1.19). Intranasal MDZ was given within 1 minute after EEG seizure onset in 171 seizures. An intraindividual comparison of seizures with and without application of in-MDZ was feasible in 171 patients, demonstrating that in-MDZ reduced the occurrence of any (Cox proportional-hazard model P < .001) and generalized tonic-clonic seizure (Cox proportional-hazard model P = .0167) over a period of 24 hours. The seizure-free time span was doubled from a median of 5.0 hours in controls to a median of 10.67 hours after in-MDZ administration. We additionally clustered in-MDZ administrations for the 119 patients who received in-MDZ more than once, comparing them with the index cases without in-MDZ. Even when considering subsequent seizures with in-MDZ administration, a patient receiving in-MDZ is still half as likely to incur another seizure in the upcoming 24 hours as compared with when the same patient does not receive in-MDZ (hazard ratio 0.50; 95% CI: 0.42-0.60; P < .01). Intranasal MDZ was well tolerated without major adverse events. The most common side effects were irritation of the nasal mucosa (37 cases [8.1%]), prolonged sedation (26 cases [5.7%]), and nausea and vomiting (12 cases [2.6%]). A decline in oxygen saturation was measured after 78 seizures (17%).

Conclusion:

We conclude that in-MDZ is a safe and efficient treatment option to prevent short-term recurrence of seizures. Intranasal MDZ can be administered very quickly by trained staff within 1 to 2 minutes after seizure onset. No major cardiocirculatory or respiratory adverse events were observed.

Epilepsy Benchmarks Area III: Improved Treatment Options for Controlling Seizures and Epilepsy-Related Conditions Without Side Effects

The goals of Epilepsy Benchmark Area III involve identifying areas that are ripe for progress in terms of controlling seizures and patient symptoms in light of the most recent advances in both basic and clinical research. These goals were developed with an emphasis on potential new therapeutic strategies that will reduce seizure burden and improve quality of life for patients with epilepsy. In particular, we continue to support the proposition that a better understanding of how seizures are initiated, propagated, and terminated in different forms of epilepsy is central to enabling new approaches to treatment, including pharmacological as well as surgical and device-oriented approaches. The stubbornly high rate of treatment-resistant epilepsy—one-third of patients—emphasizes the urgent need for new therapeutic strategies, including pharmacological, procedural, device linked, and genetic. The development of new approaches can be advanced by better animal models of seizure initiation that represent salient features of human epilepsy, as well as humanized models such as induced pluripotent stem cells and organoids. The rapid advances in genetic understanding of a subset of epilepsies provide a path to new and direct patient-relevant cellular and animal models, which could catalyze conceptualization of new treatments that may be broadly applicable across multiple forms of epilepsies beyond those arising from variation in a single gene. Remarkable advances in machine learning algorithms and miniaturization of devices and increases in computational power together provide an enhanced opportunity to detect and mitigate seizures in real time via devices that interrupt electrical activity directly or administer effective pharmaceuticals. Each of these potential areas for advance will be discussed in turn.

Evaluation of Pharmacokinetics and Dose Proportionality of Diazepam After Intranasal Administration of NRL-1 to Healthy Volunteers

NRL‐1 is a novel intranasal formulation of diazepam that is being evaluated as rescue medication in patients with epilepsy who experience bouts of increased seizure activity despite stable regimens of antiepileptic drugs. This phase 1, open‐label, randomized, crossover study in healthy adult volunteers consisted of 3 single‐dose periods (5, 10, and 20 mg) followed by a 2‐dose period (2 × 10 mg) with a minimum 28‐day washout between treatments. Blood samples were taken at prespecified time points after intranasal dosing, and bioanalytic analysis of diazepam and nordiazepam was conducted using a validated liquid chromatography–tandem mass spectrometry method. Plasma pharmacokinetic parameters were summarized using descriptive statistics, and dose proportionality (peak concentration [C_max] and area under the plasma concentration–time curve [AUC_0‐∞]) was evaluated based on a power model within a 90%CI of 0.84 to 1.16. Comparisons were also conducted between single 10‐mg dose and multidose (2 × 10 mg) treatments. NRL‐1 administration resulted in rapid diazepam absorption (median time to peak concentration 1.4‐1.5 hours). Plasma concentration‐time profiles showed similar patterns of exposure that appeared to be dose dependent, with C_max of 85.6, 133.6, and 235.3 ng/mL for the 5‐, 10‐, and 20‐mg doses, respectively, although the lower 90%CI for C_max and AUC_0‐∞ exceeded dose proportionality criteria. The coefficient of variation ranged from 59% to 67% for C_max and 48% to 56% for AUC parameters. Dose‐normalized AUC_0–∞ values were comparable between the 2 × 10‐mg and single 10‐mg doses. Treatment‐emergent adverse events were consistent with those expected for diazepam, with transient somnolence the most frequent adverse event (94.4%). These results support NRL‐1 as a potential therapy for managing seizure emergencies.