Transnasal Revolution? The Promise of Midazolam Spray to Prevent Seizure Clusters

Bioavailability and Safety of a New Highly Concentrated Midazolam Nasal Spray Compared to Buccal and Intravenous Midazolam Treatment in Chinese Healthy Volunteers

Introduction

Buccal midazolam treatment is licensed in the European Union for prolonged acute convulsive seizures in children and adolescents, but the buccal pathway is often hampered by jaw clenching, hypersalivation, or uncontrolled swallowing. Midazolam formulations that are more secure, reliable, and faster for use are needed in the acute setting. Pharmacokinetics and comparative bioavailability of intranasally administered midazolam and two midazolam intravenous solutions administered buccally or intravenously in healthy adults were evaluated.

Methods

In this phase 1, open-label, randomized, single-dose, three-period, three-sequence crossover study, 12 healthy adults (19–41 years) were randomly assigned to receive 2.5 mg midazolam intranasally; 2.5 mg midazolam intravenously; 2.5 mg midazolam buccally. Blood samples were collected for 10 h post dose to determine pharmacokinetic profiles. Adverse events and vital signs were recorded.

Results

Intranasal administration of 2.5 mg midazolam demonstrated a more rapid median time to C_max compared to buccal administration of midazolam (T_max, 12.6 min vs. 45 min; C_max, 38.33 ng/ml vs. 24.97 ng/ml). The antiepileptic effect of intranasal and buccal midazolam treatment lasted less than 4 h and generally did not differ from intravenously administered midazolam. No serious adverse events or deaths were reported, and no treatment-emergent adverse events led to study discontinuation.

Conclusion

Intranasal administration of midazolam may be a preferable alternative to the currently approve buccal midazolam treatment for prolonged acute convulsive seizures in children and adolescents.

Trial Registration

This study is registered at the Chinese Clinical Trial [http://www.chictr.org.cn] (ChiCTR2000032595) on 3 May, 2020.

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.

A systematic review of seizure clusters: Prevalence, risk factors, burden of disease and treatment patterns

Seizure clusters (SCs) are episodes of consecutive seizures that occur within a short period. The treatment patterns of rescue medications (RMs), as well as the burden of SCs, have not been assessed. A systematic literature search on Embase.com (in PubMed and Embase), supplemented with keyword-based and bibliographic searches, identified 44 articles for disease burden, three treatment guidelines, and three articles for treatment patterns. Common SC definitions were ≥3 seizures/24 h, ≥2/24 h and ≥2/6 h. The rate of SCs in prospective studies ranged from 21.7 %-42.5 %. The frequency of status epilepticus (SE) was higher in SC patients. SCs were associated with higher seizure frequency, higher risk of treatment resistance, and lower likelihood of seizure remission. Quality of life (QoL) was lower in children with SCs than in those with isolated seizures. Seizure-related hospitalization was more common in SC than non-SC patients. SCs adversely affected the productivity of patients and their caregivers. In outpatients with SCs, RMs were prescribed to 24.6 %-89.6 % and utilized by 15.6 %-44.5 %, with rates being higher in children. Key reasons for RM under-utilization were lack of seizure action plans, poor physician-patient communication, and concerns with administration route. In conclusion, SCs are associated with a higher risk of SE, treatment resistance, and low rate of seizure remission. They adversely affect patient and caregiver QoL and work productivity. However, RMs are under-prescribed, and there is an urgent need to improve recognition of SCs, improve use of seizure action plans, and remove barriers to RM use.