Intranasal Midazolam: Pharmacokinetics and Pharmacodynamics Assessed by Quantitative EEG in Healthy Volunteers

Characterization of Pediatric Rectal Absorption, Drug Disposition, and Sedation Level for Midazolam Gel Using Physiologically Based Pharmacokinetic/Pharmacodynamic Modeling

This study aims to explore and characterize the role of pediatric sedation via rectal route. A pediatric physiologically based pharmacokinetic-pharmacodynamic (PBPK/PD) model of midazolam gel was built and validated to support dose selection for pediatric clinical trials. Before developing the rectal PBPK model, an intravenous PBPK model was developed to determine drug disposition, specifically by describing the ontogeny model of the metabolic enzyme. Pediatric rectal absorption was developed based on the rectal PBPK model of adults. The improved Weibull function with permeability, surface area, and fluid volume parameters was used to extrapolate pediatric rectal absorption. A logistic regression model was used to characterize the relationship between the free concentrations of midazolam and the probability of sedation. All models successfully described the PK profiles with absolute average fold error (AAFE) < 2, especially our intravenous PBPK model that extended the predicted age to preterm. The simulation results of the PD model showed that when the free concentrations of midazolam ranged from 3.9 to 18.4 ng/mL, the probability of "Sedation" was greater than that of "Not-sedation" states. Combined with the rectal PBPK model, the recommended sedation doses were in the ranges of 0.44-2.08 mg/kg for children aged 2-3 years, 0.35-1.65 mg/kg for children aged 4-7 years, 0.24-1.27 mg/kg for children aged 8-12 years, and 0.20-1.10 mg/kg for adolescents aged 13-18 years. Overall, this model mechanistically quantified drug disposition and effect of midazolam gel in the pediatric population, accurately predicted the observed clinical data, and simulated the drug exposure for sedation that will inform dose selection for following pediatric clinical trials.

Pharmacokinetics and pharmacodynamics of cyclodextrin-based oral drug delivery formulations for disease therapy

Oral drug administration has become the most common and preferred mode of disease treatment due to its good medication adherence and convenience. For orally administered drugs, the safety, efficacy, and targeting ability requirements have grown as disease treatment research advances. It is difficult to obtain prominent efficacy of traditional drugs simply via oral administration. Numerous studies have demonstrated that cyclodextrins (CDs) can improve the clinical applications of certain orally administered drugs by enhancing their water solubility and masking undesirable odors. Additionally, deeper studies have discovered that CDs can influence disease treatment by altering the drug pharmacokinetics (PK) or pharmacodynamics (PD). This review highlights recent research progress on the PK and PD effects of CD-based oral drug delivery in disease therapy. Firstly, the review describes the characteristics of current drug delivery modes in oral administration. Besides, we minutely summarized the different CD-containing drugs, focusing on the impact of CD-based alterations in PK or PD of orally administered drugs in treating diseases. Finally, we deeply discussed current challenges and future opportunities with regard to PK and PD of CD-based oral drug delivery formulations.

Electrophysiological signatures of anxiety in Parkinson's disease

Anxiety is a common non-motor symptom in Parkinson's disease (PD) occurring in up to 31% of the patients and affecting their quality of life. Despite the high prevalence, anxiety symptoms in PD are often underdiagnosed and, therefore, undertreated. To date, functional and structural neuroimaging studies have contributed to our understanding of the motor and cognitive symptomatology of PD. Yet, the underlying pathophysiology of anxiety symptoms in PD remains largely unknown and studies on their neural correlates are missing. Here, we used resting-state electroencephalography (RS-EEG) of 68 non-demented PD patients with or without clinically-defined anxiety and 25 healthy controls (HC) to assess spectral and functional connectivity fingerprints characterizing the PD-related anxiety. When comparing the brain activity of the PD anxious group (PD-A, N = 18) to both PD non-anxious (PD-NA, N = 50) and HC groups (N = 25) at baseline, our results showed increased fronto-parietal delta power and decreased frontal beta power depicting the PD-A group. Results also revealed hyper-connectivity networks predominating in delta, theta and gamma bands against prominent hypo-connectivity networks in alpha and beta bands as network signatures of anxiety in PD where the frontal, temporal, limbic and insular lobes exhibited the majority of significant connections. Moreover, the revealed EEG-based electrophysiological signatures were strongly associated with the clinical scores of anxiety and followed their progression trend over the course of the disease. We believe that the identification of the electrophysiological correlates of anxiety in PD using EEG is conducive toward more accurate prognosis and can ultimately support personalized psychiatric follow-up and the development of new therapeutic strategies.

Development of a pharmacokinetic and pharmacodynamic model for intranasal administration of midazolam in older adults: a single-site two-period crossover study

BACKGROUND

Intranasal midazolam can produce procedural sedation in frail older patients with dementia who are unable to tolerate necessary medical or dental procedures during domiciliary medical care. Little is known about the pharmacokinetics and pharmacodynamics of intranasal midazolam in older (>65 yr old) people. The aim of this study was to understand the pharmacokinetic/pharmacodynamic properties of intranasal midazolam in older people with the primary goal of developing a pharmacokinetic/pharmacodynamic model to facilitate safer domiciliary sedation care.

METHODS

We recruited 12 volunteers: ASA physical status 1-2, aged 65-80 yr, and received midazolam 5 mg intravenously and 5 mg intranasally on two study days separated by a 6 day washout period. Concentrations of venous midazolam and 1'-OH-midazolam, Modified Observer's Assessment of Alertness/Sedation (MOAA/S) score, bispectral index (BIS), arterial pressure, ECG, and respiratory parameters were measured for 10 h.

RESULTS

Time to peak effect of intranasal midazolam for BIS, MAP, and SpO₂ were 31.9 (6.2), 41.0 (7.6), and 23.1 (3.0) min, respectively. Intranasal bioavailability was lower compared with intravenous administration (F_abs 95%; 95% confidence interval: 89-100%). A three-compartment model best described midazolam pharmacokinetics following intranasal administration. A separate effect compartment linked to the dose compartment best described an observed time-varying drug-effect difference between intranasal and intravenous midazolam, suggesting direct nose-to-brain transport.

CONCLUSIONS

Intranasal bioavailability was high and sedation onset was rapid, with maximum sedative effects after 32 min. We developed a pharmacokinetic/pharmacodynamic model for intranasal midazolam for older persons and an online tool to simulate changes in MOAA/S, BIS, MAP, and SpO₂ after single and additional intranasal boluses.

CLINICAL TRIAL REGISTRATION

EudraCT (2019-004806-90).

A randomized phase 2b efficacy study in patients with seizure episodes with a predictable pattern using Staccato® alprazolam for rapid seizure termination

OBJECTIVE

Alprazolam administered via the Staccato® breath-actuated device is delivered into the deep lung for rapid systemic exposure and is a potential therapy for rapid epileptic seizure termination (REST). We conducted an inpatient study (ENGAGE-E-001 [NCT03478982]) in patients with stereotypic seizure episodes with prolonged or repetitive seizures to determine whether Staccato alprazolam rapidly terminates seizures in a small observed population after administration under direct supervision.

METHODS

Adult patients with established diagnosis of focal and/or generalized epilepsy with a documented history of seizure episodes with a predictable pattern were enrolled. They were randomized 1:1:1 to double-blind treatment of a single seizure event with one dose of Staccato alprazolam 1.0 mg or 2.0 mg, or Staccato placebo in an inpatient unit. The primary end point of the study was the proportion of responders in each treatment group achieving seizure activity cessation within 2 min after administration of study drug and no recurrence of seizure activity within 2 h.

RESULTS

A total of 273 patients were screened, and 116 randomized patients received treatment with the study drug in the double-blind part. The proportion of treated patients who were responders was 65.8% for each of Staccato alprazolam 1.0 mg (n = 38; p = .0392) and 2.0 mg (n = 38; p = .0392), compared with 42.5% for Staccato placebo (n = 40). Staccato alprazolam was well tolerated when administered as a single dose of 1.0 or 2.0 mg: cough and somnolence were the most common adverse events (AEs) (both 14.5%), followed by dysgeusia (13.2%). AEs were mostly mild or moderate in intensity; there were no treatment-related serious AEs.

SIGNIFICANCE

Both 1.0 mg and 2.0 mg doses of Staccato alprazolam demonstrated efficacy in rapidly terminating seizures in an inpatient setting and were well tolerated. The next step is a Phase 3 confirmatory study to demonstrate efficacy and safety of Staccato alprazolam for rapid cessation of seizures in an outpatient setting.

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.

Physiologically based pharmacokinetic/pharmacodynamic modeling to evaluate the absorption of midazolam rectal gel

OBJECTIVE

We aimed to 1) develop physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD) models of a novel midazolam rectal gel in healthy adults, 2) assess the contribution of different physiologically relevant factors in rectal absorption, and 3) to provide supports for future clinical studies of midazolam rectal gel.

METHODS

We developed the rectal PBPK model after built the intravenous and the oral PBPK model. Then, the physiological progress of rectal route was described in terms of the drug release, the rectal absorption and the particle first-pass elimination. Next, the validated PBPK model was combined with the sigmoid E_max PD model. This PBPK/PD model was used to identify the dose range and the critical parameters to ensure safety sedation.

RESULTS

Based on the simulations, the recommended maximum dose for adults' sedation was 15 mg. And the retention time of midazolam rectal gel should be longer than 3 h to reach over 80% pharmacokinetics and pharmacodynamics effects.

CONCLUSION

We successfully developed a PBPK/PD model for the midazolam rectal gel, which accurately described the PK/PD behavior in healthy adults and indicated the transit time of rectum was the most sensitive parameter for absorption. This PBPK/PD model would be expected to support the future clinical studies and pediatric application.

Intracranial electroencephalography features of young and old mice under midazolam administration

Understanding the electroencephalography features of young and old patients treated with anesthetic drugs is important to allow accurate drug use in elderly patients. This study aimed to monitor the intracranial electroencephalography (in the cortex and hippocampus) in free-moving young and old mice under midazolam administration. Behavioral assessment revealed that compared with young mice, old mice had a longer immobility time with a similar midazolam dose. In both young and old mice, midazolam significantly suppressed the total, δ (0.5-4 Hz), θ (4-8 Hz), and α (8-12 Hz) power, and thus induced an increase in the relative β (12-30 Hz) and γ (30-140 Hz) power. Age had a main effect on the γ frequency; specifically, under normal conditions, old mice had a lower γ power than young mice. After midazolam administration, the relative power of high γ frequency (50-140 Hz) remained lower in old mice than in young mice. Our findings suggest that a lower γ power is indicative of an aging brain.

Rescue therapies for seizure emergencies: current and future landscape

INTRODUCTION

Seizure emergencies-status epilepticus and seizure clusters-require rapid evaluation and treatment. Several consensus-based guidelines support a prompt use of intravenous benzodiazepines as the first-line therapy in seizure emergencies. However, most seizure emergencies start outside the hospital settings. Until recently, approved prehospital rescue therapies were limited to rectal diazepam and buccal midazolam (Europe only).

METHODS

The author provides a narrative review of rescue therapies for seizure emergencies based on a comprehensive literature review (PubMed and OvidSP vendors with appropriate keywords to incorporate recent evidence) to highlight the changing landscape of seizure recue therapies.

RESULTS

A commercial version of intranasal midazolam was approved by the FDA in 2019 for 12 ≥ years old with seizure clusters. In 2020, the FDA also approved a proprietary vitamin E solution-based diazepam nose spray to abort seizure clusters in ≥ 6 years old subjects. Other than these two new options, the author discussed two previously approved therapies: rectal diazepam and buccal midazolam. The review also includes the use of intramuscular diazepam and midazolam, clonazepam wafer, sublingual and intranasal lorazepam in seizure emergencies. Besides the availability of new therapies from successful trials in controlled settings, the real-world challenges of using rescue medicines in community settings are slowly emerging.

DISCUSSION

With multiple options, a more robust and updated cost-effective analysis of different rescue medicines needs to be performed using effectiveness data from the literature and cost data from publicly available market prices. Further research is also ongoing to develop alternative non-intravenous treatment options for outpatient settings. Lastly, several other non-benzodiazepine drugs, such as allopregnanolone, propofol, and brivaracetam, are also currently under development for seizure emergencies.

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.

In vitro-in vivo extrapolation of metabolic clearance using human liver microsomes: factors showing variability and their normalization

In vitro-in vivo extrapolation (IVIVE) using human liver microsomes has been widely used to predict metabolic clearance, but some of the factors used in the process of prediction show variability for the same compound: notably, microsomal intrinsic clearance values corrected by the unbound fraction (CL_{int, u}), physiological parameters used for scale-up, and the source of in vivo clearance data.The purpose of this study was to assess the correlation between in vitro and in vivo CL_int with a focus on factors showing variability using four cytochrome P450 (CYP)3A substrates.We surveyed in vivo clearance values in literature and also determined the microsomal CL_{int, u} values. A scaling factor (SF_direct) was defined as in vivo CL_int divided by the microsomal CL_{int, u}, which ranged from 1190 to 2310 (mg protein per kg body weight). The application of a mean SF_direct of 1600 (mg protein per kg body weight) and further normalization by the microsomal CL_{int, u} values of midazolam, the most commonly used substrate, resulted in improved prediction accuracy for CL_{int, u} values from various microsomal batches.The results suggest the normalization of variability might be useful for predicting the in vivo CL_int.

Intranasal midazolam as first-line inhospital treatment for status epilepticus: a pharmaco-EEG cohort study

Objective

We sought to evaluate the efficacy and tolerability of intranasal midazolam (in‐MDZ) as first‐line inhospital therapy in patients with status epilepticus (SE) during continuous EEG recording.

Methods

Data on medical history, etiology and semiology of SE, anticonvulsive medication usage, efficacy and safety of in‐MDZ were retrospectively reviewed between 2015 and 2018. Time to end of SE regarding the administration of in‐MDZ and ß‐band effects were analyzed on EEG and with frequency analysis.

Results

In total, 42 patients (mean age: 52.7 ± 22.7 years; 23 females) were treated with a median dose of 5 mg of in‐MDZ (range: 2.5–15 mg, mean: 6.4 mg, SD: 2.6) for SE. The majority of the patients suffered from nonconvulsive SE (n = 24; 55.8%). In total, 24 (57.1%) patients were responders, as SE stopped following the administration of in‐MDZ without any other drugs being given. On average, SE ceased on EEG at 05:05 (minutes:seconds) after the application of in‐MDZ (median: 04:56; range: 00:29–14:53; SD:03:13). Frequency analysis showed an increased ß‐band on EEG after the application of in‐MDZ at 04:07 on average (median: 03:50; range: 02:20–05:40; SD: 01:09). Adverse events were recorded in six patients (14.3%), with nasal irritations present in five (11.9%) and prolonged sedation occurring in one (2.6%) patient.

Conclusions

This pharmaco‐EEG–based study showed that in‐MDZ is effective and well‐tolerated for the acute treatment of SE. EEG and clinical effects of in‐MDZ administration occurred within 04:07 and 5:05 on average. Intranasal midazolam appears to be an easily applicable and rapidly effective alternative to buccal or intramuscular application as first‐line treatment if an intravenous route is not available.

Inhaled alprazolam rapidly suppresses epileptic activity in photosensitive participants

OBJECTIVE

Treatment options for seizure clusters are limited; the need for easy-to-administer treatments remains. The Staccato system delivers drug deep into the lung via inhalation. In this phase 2a study, we investigated the ability of three different doses of Staccato alprazolam to suppress the electroencephalographic (EEG) photoparoxysmal response (PPR) compared with placebo in participants with photosensitive seizures.

METHODS

Adults (18-60 years) with a diagnosis and history of PPR on EEG with or without an epilepsy diagnosis were eligible to participate. Participants received Staccato alprazolam 0.5, 1.0, and 2.0 mg, and Staccato placebo (twice) in random order. Intermittent photic stimulation and clinical assessments were performed at one predose and seven postdose time points. The primary endpoint of the study was the change in standardized photosensitivity range (SPR) in participants receiving each dose of Staccato alprazolam.

RESULTS

Fifteen participants with a prior epilepsy diagnosis were screened; five were enrolled, randomized, and completed the study. All participants were white females with a mean (SD) age of 27.2 (6.8) years. All doses of Staccato alprazolam reduced the SPR at 2 minutes; the effect was sustained through 4 hours for the 0.5-mg dose and 6 hours for the 1.0- and 2.0-mg doses. The magnitude and duration of sedation and sleepiness were dose-related. Four participants (80%) experienced ≥1 adverse event (AE); none was severe or serious. Cough, diarrhea, dysgeusia, oral dysesthesia, sedation, and somnolence were experienced by two participants (40%) each.

SIGNIFICANCE

This proof-of-concept study demonstrated that Staccato alprazolam 0.5, 1.0, and 2.0 mg rapidly suppressed epileptiform activity in photosensitive participants with epilepsy. The AE profile of Staccato alprazolam was similar to what has been reported for alprazolam for other indications. The results support further development of Staccato alprazolam as a rescue medication for the acute treatment of seizures.

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.

Predictors for drug effects with brain disease: Shed new light from EEG parameters to brain connectomics

Though researchers spent a lot of effort to develop treatments for neuropsychiatric disorders, the poor translation of drug efficacy data from animals to human hampered the success of these therapeutic approaches in human. Pharmaceutical industry is challenged by low clinical success rates for new drug registration. To maximize the success in drug development, biomarkers are required to act as surrogate end points and predictors of drug effects. The pathology of brain disease could be in part due to synaptic dysfunction. Electroencephalogram (EEG), generating from the result of the postsynaptic potential discharge between cells, could be a potential measure to bridge the gaps between animal and human data. Here we discuss recent progress on using relevant EEG characteristics and brain connectomics as biomarkers to monitor drug effects and measure cognitive changes on animal models and human in real-time. It is expected that the novel approach, i.e. EEG connectomics, will offer a deeper understanding on the drug efficacy at a microcirculatory level, which will be useful to support the development of new treatments for neuropsychiatric disorders.

Pharmacokinetics and pharmacodynamics of a new highly concentrated intranasal midazolam formulation for conscious sedation

AIM

To evaluate the pharmacokinetics, pharmacodynamics, nasal tolerance and effects on sedation of a highly concentrated aqueous intranasal midazolam formulation (Nazolam) and to compare these to intravenous midazolam.

METHODS

In this four-way crossover, double-blind, double-dummy, randomized, placebo-controlled study, 16 subjects received 2.5 mg Nazolam, 5.0 mg Nazolam, 2.5 mg intravenous midazolam or placebo on different occasions. Pharmacokinetics of midazolam and α-hydroxy-midazolam were characterized and related to outcome variables for sedation (saccadic peak velocity, the Bond and Lader visual analogue scale for sedation, the simple reaction time task and the observer's assessment of alertness/sedation). Nasal tolerance was evaluated through subject reporting, and ear, nose and throat examination.

RESULTS

Nazolam bioavailability was 75%. Maximal plasma concentrations of 31 ng ml^-1 (CV, 42.3%) were reached after 11 min (2.5 mg Nazolam), and of 66 ng ml^-1 (coefficient of variability, 31.5%) after 14 min (5.0 mg Nazolam). Nazolam displayed a significant effect on OAA/S scores. Sedation onset (based on SPV change) occurred 1 ± 0.7 min after administration of 2.5 mg intravenous midazolam, 7 ± 4.4 min after 2.5 mg Nazolam, and 4 ± 1.8 min after 5 mg Nazolam. Sedation duration was 118 ± 95.6 min for 2.5 mg intravenous midazolam, 76 ± 80.4 min for 2.5 mg Nazolam, and 145 ± 104.9 min for 5.0 mg Nazolam. Nazolam did not lead to nasal mucosa damage.

CONCLUSIONS

This study demonstrates the nasal tolerance, safety and efficacy of Nazolam. When considering the preparation time needed for obtaining venous access, conscious sedation can be achieved in the same time span as needed for intravenous midazolam. Nazolam may offer important advantages in conscious sedation.

Pharmacokinetics, pharmacodynamics, and safety of USL261, a midazolam formulation optimized for intranasal delivery, in a randomized study with healthy volunteers

OBJECTIVE

To compare the pharmacokinetics, pharmacodynamics, and tolerability of USL261, a midazolam formulation optimized for intranasal delivery, versus midazolam intravenous (IV) solution administered intranasally (MDZ-inj IN) or intravenously (MDZ-inj IV) in healthy adults.

METHODS

In this phase 1, five-way crossover, open-label study, 25 healthy adults (aged 18-42 years) were randomly assigned to receive 2.5, 5.0, and 7.5 mg USL261; 2.5 mg MDZ-inj IV; and 5.0 mg MDZ-inj IN. Blood samples were collected for 12 h post dose to determine pharmacokinetic profiles. Pharmacodynamic assessments of sedation and psychomotor impairment also were conducted. Adverse events, oxygen saturation, and vital signs were recorded.

RESULTS

Increasing USL261 dose corresponded with increases in midazolam area under the concentration time curve (AUC) and maximum observed plasma concentration (Cmax ), with all doses demonstrating rapid median time to Cmax (Tmax ; 10-12 min). USL261 also demonstrated increased absorption, with a 134% relative bioavailability, compared with the same MDZ-inj IN dose. USL261 was associated with dose-dependent increases in sedation and psychomotor impairment (p < 0.05); however, these effects lasted <4 h and generally did not differ from MDZ-inj IN or MDZ-inj IV at comparable doses. No serious adverse events (SAEs) or deaths were reported, and no treatment-emergent adverse events (TEAEs) led to study discontinuation.

SIGNIFICANCE

Compared with intranasal delivery of a midazolam formulation intended for IV delivery, USL261, optimized for intranasal administration demonstrated improved bioavailability with similar pharmacodynamic effects. Therefore, USL261 may be a preferable alternative to the currently approved rectal diazepam treatment for intermittent bouts of increased seizure activity.

Intranasal midazolam for the emergency management of hypercyanotic spells in tetralogy of Fallot

The case of a 2-month-old boy with previously diagnosed tetralogy of Fallot who was brought to the emergency department with a hypercyanotic spell is described. Because partly of the difficulty of intravenous placement, especially in an infant crying with marked hypernea and deeply cyanotic, intranasal midazolam was administered. Before 3 minutes of hypernea terminated increasing the oxygen saturation successfully and intravenous line was easily placed with the baby remaining in calm. Sedation is an important step in the management of patients with cyanotic spells. Intranasal midazolam offers an alternative use as an initial method of calming the child that was effective in a patient with a severe cyanotic spell because of tetralogy of Fallot in the emergency department.

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

Management of seizure emergencies substantially changed after the introduction of rectal diazepam in Europe in the 1970s and in the United States in the 1990s. Although safe and effective, social objections and legal concerns have limited use of rectal diazepam products in out-of-hospital treatment of seizure emergencies. Shortly after the introduction of Diastat (diazepam rectal gel), commercial development of innovative formulations began involving several benzodiazepines and routes of administration, including buccal, IM, nasal, and subcutaneous. All benzodiazepines have the same mechanism of action; however, there are major differences in physicochemical properties and pharmacokinetic characteristics, which affect the choice of drug and route. This article highlights some of those differences and their effect on selection of therapies for treating seizure emergencies. We also present results from key clinical studies of these drugs and provide an update on current status of new products under development.