Development of benzodiazepines for out-of-hospital management of seizure emergencies

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.

Current summary of the evidence in drone-based emergency medical services care

Interventions for many medical emergencies including cardiac arrests, strokes, drug overdoses, seizures, and trauma, are critically time-dependent, with faster intervention leading to improved patient outcomes. Consequently, a major focus of emergency medical services (EMS) systems and prehospital medicine has been improving the time until medical intervention in these time-sensitive emergencies, often by reducing the time required to deliver critical medical supplies to the scene of the emergency. Medical indications for using unmanned aerial vehicles, or drones, are rapidly expanding, including the delivery of time-sensitive medical supplies. To date, the drone-based delivery of a variety of time-critical medical supplies has been evaluated, generating promising data suggesting that drones can improve the time interval to intervention through the rapid delivery of automatic external defibrillators (AEDs), naloxone, antiepileptics, and blood products. Furthermore, the improvement in the time until intervention offered by drones in out-of-hospital emergencies is likely to improve patient outcomes in time-dependent medical emergencies. However, barriers and knowledge gaps remain that must be addressed. Further research demonstrating functionality in real-world scenarios, as well as research that integrates drones into the existing EMS structure will be necessary before drones can reach their full potential. The primary aim of this review is to summarize the current evidence in drone-based Emergency Medical Services Care to help identify future research directions.

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.

Introduction to use of an acute seizure action plan for seizure clusters and guidance for implementation

It is important for patients with epilepsy and their caregivers, including care partners, to understand the patient's seizure clusters and what to do when they occur. In many instances, seizure clusters are unique to each patient. The knowledge gained from understanding a patient's seizure cluster or seizure pattern provides a foundation for taking prompt action to prevent worsening to prolonged seizures, status epilepticus, and potentially death. Seizure action plans (SAPs), which are similar to the disease-related treatment action plans for other conditions, can be developed by a health care provider (HCP) in conjunction with the patient with epilepsy and/or caregivers, and SAPs are specifically customized for the individual patient and his or her seizure management. However, the current literature lacks unified guidance on how to design SAPs that will help prepare patients and caregivers for rapidly determining and initiating appropriate treatment of acute seizure emergencies in the community and at home. Here, we examine the current usage and value of SAPs for pediatric and adult patients with epilepsy, and we introduce the concept of the acute SAP (ASAP) for use specifically during seizure emergencies, such as seizure clusters. This type of standardized, simplified, and customized plan can rapidly and concisely provide patients and caregivers with a practical protocol to treat a seizure cluster consistently, appropriately, and in a timely manner. Details on potential content and formats of ASAPs are provided. Following this is a discussion of barriers to ASAP use that may affect HCPs or patients and caregivers, including lack of standardization, relevance, and personalization and pitfalls associated with technology. This leads into a discussion of guidance for developing, implementing, and updating ASAPs that suggests ways to address the barriers and ensure that the ASAP is best suited to the patient's needs.

Quality-of-life results in adults with epilepsy using diazepam nasal spray for seizure clusters from a long-term, open-label safety study

BACKGROUND

The impact of seizure clusters and the use of intermittent rescue therapy for clusters on the quality of life (QoL) of patients with epilepsy has not been widely studied. The present analysis assessed QoL as a secondary endpoint among adult patients with seizure clusters enrolled in a long-term, phase 3, open-label safety study (NCT02721069) of diazepam nasal spray (Valtoco®). The QoL aspect of patients in this study has not been previously published.

METHODS

The 12-month safety study of diazepam nasal spray enrolled patients aged 6-65 years with seizure clusters. Adults aged ≥18 years completed the Quality of Life in Epilepsy (QOLIE)-31-P at baseline (day 0) and days 30, 150, 270, and 365. This instrument includes questions about patient health and daily activities with numeric values (1-100) assigned to responses; higher scores indicate better QoL. The QOLIE-31-P includes 7 subscales: Seizure Worry, Overall QoL, Emotional Well-Being, Energy/Fatigue, Cognitive Functioning, Medication Effects, and Social Functioning; an Overall Score is calculated as a weighted composite of the 7 subscales. Comparisons were made between subgroups of patients who had frequent (≥2) and infrequent (<2) monthly dosing of diazepam nasal spray and those whose doses were administered by the patient or a care partner. This safety study was not powered to assess efficacy endpoints; descriptive statistics were calculated across time points. In addition, safety measures, including treatment-emergent adverse events, are reported.

RESULTS

Seventy-two adults who responded to the QOLIE-31-P were included in the analyses. Mean QOLIE-31-P scores were stable or increased across time points. The mean total scores increased from day 0 to day 365 by 5.2 among patients providing data for ≥1 time point (follow-up group) and 2.2 among patients providing data at all time points (QOLIE all-assessments subgroup). Subscale means for Seizure Worry and Social Functioning showed the greatest numeric increase from baseline. Mean QOLIE-31-P scores were similar in all subgroups. The safety profile in the follow-up group was similar to that seen in all study adults.

CONCLUSIONS

Adults with refractory epilepsy who were treated with diazepam nasal spray for seizure clusters maintained or improved QOLIE subscale scores across the 12-month study period. Seizure Worry and Social Functioning subscale scores increased over time, suggesting improvement in these domains for this population with intractable epilepsy. Changes among subscale results suggest differences in sensitivity to the use of an intermittent treatment. The potential to improve patient function with treatment for seizure clusters warrants further study.

A review of a diazepam nasal spray for the treatment of acute seizure clusters and prolonged seizures

INTRODUCTION

Some people with epilepsy experience acute repetitive seizures (ARS), also termed seizure clusters, which have a negative impact on patient and caregiver quality of life, emotional wellbeing, daily function, and may pose risk of injury or death. In addition, these events increase healthcare utilization in emergency departments and hospitals, which might be avoided with use of an at-home rescue medication. Intranasal formulations of benzodiazepines used as rescue medications provide a means of delivering rescue medication that is socially acceptable and more easily administered than rectal drug.

AREAS COVERED

This article provides a review of intranasal diazepam covering development, pharmacokinetics, dosing, safety, adverse effects, and efficacy. The authors compare it with rectal diazepam and intranasal midazolam.

EXPERT OPINION

Intranasal rescue drugs are a valuable treatment modality for seizure clusters and prolonged seizures that are effective and well tolerated with the potential to enhance patient quality of life, reduce the incidence of seizure-related injury, and lessen the need for hospital visits. The literature does not provide evidence comparing the various rescue agents, and head-to-head comparison studies are needed. An inhaled benzodiazepine as a seizure rescue drug is currently undergoing clinical trials.

Lack of observed impact of history or concomitant treatment of seasonal allergies or rhinitis on repeated doses of diazepam nasal spray administered per seizure episode in a day, safety, and tolerability: Interim results from a phase 3, open-label, 12-month repeat-dose safety study

Intranasal formulations are commonly used for drug delivery, and the literature has shown that seasonal allergies do not affect nasal administration of some agents. Diazepam nasal spray (Valtoco®) is a proprietary intranasal formulation with n-dodecyl-beta-d-maltoside (Intravail® A3) that is indicated for acute treatment of seizure clusters in patients with epilepsy aged 6 years and older. The analysis presented here is from an interim cutoff of a phase 3 open-label study evaluating the safety and tolerability of diazepam nasal spray. This analysis assessed whether seasonal allergies alter control of seizures with an intranasal formulation, using administration of a second dose as a surrogate efficacy endpoint. Of 158 evaluated patients with epilepsy having seizures despite a stable anti-seizure regimen, 62 patients had medical histories that included seasonal allergies or rhinitis. The results of this analysis show that seasonal allergies did not appear to influence use of a second dose; the groups of patients with and without a history of seasonal allergies both presented with low rates of seizure episodes for which a second dose was used, which suggests that there is not a major difference in pattern of use. Diazepam nasal spray demonstrated a similar safety and tolerability profile in patients with and without a history of seasonal allergies.

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.

A Short Review on the Intranasal Delivery of Diazepam for Treating Acute Repetitive Seizures

Benzodiazepines such as diazepam, lorazepam and midazolam remained the mainstay of treatment for acute repetitive seizures (ARS). The immediate care for ARS should often begin at home by a caregiver. This prevents the progression of ARS to prolonged seizures or status epilepticus. For a long time and despite social objections rectal diazepam gel remained only FDA-approved rescue medication. Intranasal administration of benzodiazepines is considered attractive and safe compared with rectal, buccal and sublingual routes. Intranasal delivery offers numerous advantages such as large absorptive surface area, bypass the first-pass metabolism and good patient acceptance as it is needle free and painless. Recent clinical studies have demonstrated that diazepam nasal spray (NRL-1; Valtoco^®, Neurelis Inc.,San Diego, CA, USA) showed less pharmacokinetic variability and reliable bioavailability compared with the diazepam rectal gel. Diazepam nasal spray could be considered as a suitable alternative for treating seizure emergencies outside the hospital. This review summarizes the treatment options for ARS and findings from clinical studies involving intranasal diazepam for treating seizure emergencies.

Safety and tolerability associated with chronic intermittent use of diazepam buccal film in adult, adolescent, and pediatric patients with epilepsy

Objective

Diazepam buccal film (DBF) is in development for treatment of patients experiencing bouts of increased seizure activity. We assessed safety, tolerability, and usability of self‐ or caregiver‐administered DBF in the outpatient setting.

Methods

Patients aged 2‐65 years needing treatment with a rescue benzodiazepine at least once monthly were eligible for the study. DBF (5‐17.5 mg) was dispensed based on age and body weight. Patients/caregivers administered DBF for up to five seizure episodes per month. Adverse events (AEs) and usability assessments were recorded after the first dose, then every 3 months.

Results

Onehundred eighteen patients who used ≥1 DBF dose (adults, n = 82; adolescents, n = 19; children, n = 17) were enrolled. Eleven treatment‐related AEs (10 being mild or moderate in severity) occurred in nine (7.6%) patients over a mean of 243 days of follow‐up. No patient discontinued participation because of AEs. Mild local buccal discomfort, buccal swelling, and cheek skin sensitivity were reported by one patient each. Twenty‐two serious AEs were reported; one was treatment‐related. The three deaths reported, all unrelated to DBF, resulted from seizures or seizure with brain malignancy. Self‐administration by adults was attempted on 23.6% (188/795) of use occasions. Administration of DBF occurred under ictal or peri‐ictal conditions on 49.5% (538/1087) of use occasions, and DBF was successfully administered on a first or second attempt on 96.6% (1050/1087) of use occasions. Overall, patients received their dose of DBF on 99.2% (1078/1087) of use occasions. A second DBF dose was required within 24 hours after the first dose on 8.5% (92/1087) of use occasions.

Significance

In this observational study of chronic intermittent use, DBF was easy to administer, safe, and well tolerated in adult, adolescent, and pediatric patients with epilepsy experiencing seizure emergencies. DBF can be readily self‐administered by adults with epilepsy, as well as successfully administered by a caregiver in seizure emergencies.

Diazepam buccal film for the treatment of acute seizures

Benzodiazepines, including diazepam and midazolam, are the mainstay of treatment for seizure emergencies, including acute repetitive seizures. Nonparenteral dosage forms are used when parenteral (intravenous or intramuscular) dosing is not feasible. Currently available nonparenteral dosage forms have limitations in terms of usability, patient and caregiver acceptance, speed of action, and portability. Diazepam buccal film (DBF) is a compact, easily administered diazepam formulation. When placed onto the buccal mucosa inside the cheek, DBF adheres firmly and then rapidly dissolves, delivering diazepam transbucally and via the gastric route. In fasted healthy male volunteers, plasma levels were achieved rapidly after DBF placement in a linear dose-proportional fashion. Bioavailability in adult patients with epilepsy was not significantly different when DBF was applied interictally or periictally (within 5 min of a seizure). Diazepam buccal film was successfully placed and generally used without difficulty, even without patient cooperation immediately after a seizure. In a crossover comparative study with diazepam rectal gel (Diastat®) in adult patients with epilepsy, DBF performed equivalently to the rectal gel, but peak exposures were less variable. Diazepam buccal film is a convenient alternative for out-of-hospital treatment of seizure exacerbations. Proceedings of the 7th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures.

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

OBJECTIVE

To evaluate safety- and seizure-related outcomes with repeated intermittent use of a novel formulation of midazolam administered as a single-dose nasal spray (MDZ-NS) in the outpatient treatment of patients experiencing seizure clusters (SCs).

METHODS

In this open-label extension trial (ClinicalTrials.gov NCT01529034), patients aged ≥12 years and on a stable regimen of antiepileptic drugs who completed the original phase III, randomized controlled trial were enrolled. Caregivers administered MDZ-NS 5 mg when patients experienced SCs; a second dose could be given if seizures did not terminate within 10 minutes or recurred within 10 minutes-6 hours. Patients were monitored for treatment-emergent adverse events (TEAEs) throughout, and the main seizure-related outcome was treatment success, defined as seizure termination within 10 minutes and no recurrence 10 minutes-6 hours after drug administration.

RESULTS

Of 175 patients enrolled, 161 (92.0%) received ≥1 MDZ-NS dose, for a total of 1998 SC episodes. Median time spent by patients in the trial was 16.8 months (range = 1-55.7 months). TEAEs were experienced by 40.4% of patients within 2 days of drug administration and 57.1% overall. TEAEs reported by most patients (within 2 days and overall) were nasal discomfort (12.4%) and somnolence (9.3%). One patient each discontinued due to treatment-related nasal discomfort and somnolence. There were no patients with treatment-related respiratory depression, and none with TEAEs indicative of drug abuse or dependence. Treatment success criteria were met in 55% (1108/1998) of SC episodes after administration of a single 5-mg dose and in 80.2% (617/769) with the second dose. Treatment success was consistent over treated episode number.

SIGNIFICANCE

Repeated, intermittent, acute treatment of patients experiencing SCs with MDZ-NS in the outpatient setting was well tolerated over an extended period, with maintenance of efficacy suggesting lack of development of tolerance.

Rescue therapies for seizure emergencies: New modes of administration

A subgroup of patients with drug-resistant epilepsy have seizure clusters, which are a part of the continuum of seizure emergencies that includes prolonged episodes and status epilepticus. When the patient or caregiver can identify the beginning of a cluster, the condition is amenable to certain treatments, an approach known as rescue therapy. Intravenous drug administration offers the fastest onset of action, but this route is usually not an option because most seizure clusters occur outside of a medical facility. Alternate routes of administration have been used or are proposed including rectal, buccal, intrapulmonary, subcutaneous, intramuscular, and intranasal. The objective of this narrative review is to describe the (1) anatomical, physiologic, and drug physicochemical properties that need to be considered when developing therapies for seizure emergencies and (2) products currently in development. New therapies must consider parameters of Fick's law such as absorptive surface area, blood flow, membrane thickness, and lipid solubility, because these factors affect both rate and extend of absorption. For example, the lung has a 50 000-fold greater absorptive surface area than that associated with a subcutaneous injection. Lipid solubility is a physicochemical property that influences the absorption rate of small molecule drugs. Among drugs currently used or under development for rescue therapy, allopregnanolone has the greatest lipid solubility at physiologic pH, followed by propofol, midazolam, diazepam, lorazepam, alprazolam, and brivaracetam. However, greater lipid solubility correlates with lower water solubility, complicating formulation of rescue therapies. One approach to overcoming poor aqueous solubility involves the use of a water-soluble prodrug coadministered with a converting enzyme, which is being explored for the intranasal delivery of diazepam. With advances in seizure prediction technology and the development of drug delivery systems that provide rapid onset of effect, rescue therapies may prevent the occurrence of seizures, thus greatly improving the management of epilepsy.

Seizing the Opportunity: Exploring Barriers to Use of Transmucosal Midazolam in Hospice Patients

BACKGROUND

Status epilepticus seizures are distressing events for hospice and palliative care patients. Currently, rectal diazepam is the only abortive therapy approved by the U.S. Food and Drug Administration for seizures occurring out of hospital. However, transmucosal (buccal and intranasal) midazolam hydrochloride is a less expensive, equally effective, and a more socially acceptable alternative.

OBJECTIVE

To explore the use of transmucosal midazolam in out-of-hospital hospice patients in the State of Alabama.

DESIGN

A cross-sectional survey was used explore hospice providers' knowledge and use of transmucosal midazolam in clinical practice within Alabama. Setting Subjects: Hospice providers (physicians, nurses, and administrators) in the State of Alabama (n = 27).

MEASUREMENTS

An electronic survey was used to elicit transmucosal midazolam use among hospice providers.

RESULTS

Transmucosal midazolam has been documented throughout the literature and reported by expert clinicians as an efficacious, safe, and appropriate pharmaceutical intervention for the abortive treatment of seizures in adult and pediatric out-of-hospital patients. However, barriers to the use of transmucosal midazolam with hospice patients included unfamiliarity with transmucosal route and lack of provider orders. None of the participants reported transmucosal midazolam use in out-of-hospital hospice settings.

CONCLUSION

Evidence in the literature supports the use of transmucosal midazolam; however, further research is necessary to understand and address barriers in a more diverse and generalizable population.

Benzodiazepine use in seizure emergencies: A systematic review

PURPOSE

The aim of this review was to systematically examine safety and efficacy outcomes, as well as patient/caregiver satisfaction, from clinical studies in pediatric and adult patients treated with benzodiazepines (BZDs) through various administration routes in response to seizure emergencies.

METHODS

A literature search was conducted to identify articles describing the use of various routes of administration (RoAs) of BZDs for the treatment of seizure emergencies through April 21, 2015, using Embase™ and PubMed®. Eligible studies included (a) randomized controlled trials or (b) controlled nonrandomized clinical trials, either retrospective or prospective. Outcome assessments reviewed were 1) time to administration, 2) time to seizure termination, 3) rate of treatment failure, 4) prevention of seizure recurrence, 5) patient and caregiver treatment satisfaction, 6) adverse events related to BDZ treatment or RoA, and 7) respiratory adverse events.

RESULTS

Seventy-five studies evaluated safety and efficacy using individual or comparator BDZs of various RoAs for treating seizure emergencies in all-aged patients with epilepsy. Buccal, intranasal (IN), or intramuscular (IM) BZDs were often more rapidly administered compared with rectal and intravenous (IV) formulations. Time to seizure termination, seizure recurrence rates, and adverse events were generally similar among RoAs, whereas nonrectal RoAs resulted in greater patient and caregiver satisfaction compared with rectal RoA.

SIGNIFICANCE

Results of this systematic literature review suggest that nonrectal and non-IV BZD formulations provide equal or improved efficacy and safety outcomes compared with rectal and IV formulations for the treatment of seizure emergencies.

Efficacy of nonvenous medications for acute convulsive seizures: A network meta-analysis

OBJECTIVE

This is a network meta-analysis of nonvenous drugs used in randomized controlled trials (RCTs) for treatment of acute convulsive seizures and convulsive status epilepticus.

METHODS

Literature was searched according to Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines for RCTs examining treatment of acute convulsive seizures or status epilepticus with at least one of the study arms being a nonvenous medication. After demographic and outcome data extraction, a Bayesian network meta-analysis was performed and efficacy results were summarized using treatment effects and their credible intervals (CrI). We also calculated the probability of each route-drug combination being the most clinically effective for a given outcome, and provided their Bayesian hierarchical ranking.

RESULTS

This meta-analysis of 16 studies found that intramuscular midazolam (IM-MDZ) is superior to other nonvenous medications regarding time to seizure termination after administration (2.145 minutes, 95% CrI 1.308-3.489), time to seizure cessation after arrival in the hospital (3.841 minutes, 95% CrI 2.697-5.416), and time to initiate treatment (0.779 minutes, 95% CrI 0.495-1.221). Additionally, intranasal midazolam (IN-MDZ) was adjudged most efficacious for seizure cessation within 10 minutes of administration (90.4% of participants, 95% CrI 79.4%-96.9%), and persistent seizure cessation for ≥1 hour (78.5% of participants, 95% CrI 59.5%-92.1%). Paucity of RCTs produced evidence gaps resulting in small networks, routes/drugs included in some networks but not others, and some trials not being connected to any network.

CONCLUSIONS

Despite the evidence gaps, IM-MDZ and IN-MDZ exhibit the best efficacy data for the nonvenous treatment of acute convulsive seizures or status epilepticus.