Pharmacokinetics and pharmacodynamics of midazolam administered as a concentrated intranasal spray. A study in healthy volunteers

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.

Remimazolam: its clinical pharmacology and evolving role in anesthesia and sedation practice

PURPOSE OF REVIEW

Remimazolam is a novel benzodiazepine anesthetic/sedative, designed as a rapidly metabolized carboxylic acid. Since its recent launch, the role of remimazolam in modern anesthesia and sedation practice is still evolving. This review aims to outline the clinical pharmacology and clinical utility of remimazolam to elucidate its potential advantages and limitations.

RECENT FINDINGS

Remimazolam is "short-acting" but not ultra-short-acting compared with propofol based on context-sensitive decrement times. But compared to propofol, the availability of the benzodiazepine antagonist, flumazenil, is considered an advantage, particularly in certain emergency situations such as in patients with difficult airways. However, because flumazenil is shorter acting than remimazolam when remimazolam accumulates or is present in a high concentration, the reappearance of remimazolam sedation may occur after the initial reversal of anesthesia/sedation from flumazenil administration. Although it is beneficial that remimazolam causes less respiratory depression and hypotension than propofol, serious respiratory depression and hypotension can still occur. Remimazolam administration causes minimal or no pain on injection. Remimazolam is associated with less postoperative nausea and vomiting than inhaled anesthetics, but propofol is clearly superior in this regard. The anesthetic/sedative effects may be prolonged by severe hepatic impairment; remimazolam tolerance can occur in long-term benzodiazepine users.

SUMMARY

Remimazolam may be beneficial to use in procedural sedation and general anesthesia for patients with difficult airways or hemodynamic instability. Further clinical studies with remimazolam are warranted to identify the potential benefits in other settings and patient populations.

Early Postnatal Exposure to Midazolam Causes Lasting Histological and Neurobehavioral Deficits via Activation of the mTOR Pathway

Exposure to general anesthetics can adversely affect brain development, but there is little study of sedative agents used in intensive care that act via similar pharmacologic mechanisms. Using quantitative immunohistochemistry and neurobehavioral testing and an established protocol for murine sedation, we tested the hypothesis that lengthy, repetitive exposure to midazolam, a commonly used sedative in pediatric intensive care, interferes with neuronal development and subsequent cognitive function via actions on the mechanistic target of rapamycin (mTOR) pathway. We found that mice in the midazolam sedation group exhibited a chronic, significant increase in the expression of mTOR activity pathway markers in comparison to controls. Furthermore, both neurobehavioral outcomes, deficits in Y-maze and fear-conditioning performance, and neuropathologic effects of midazolam sedation exposure, including disrupted dendritic arborization and synaptogenesis, were ameliorated via treatment with rapamycin, a pharmacologic mTOR pathway inhibitor. We conclude that prolonged, repetitive exposure to midazolam sedation interferes with the development of neural circuitry via a pathologic increase in mTOR pathway signaling during brain development that has lasting consequences for both brain structure and function.

Niclosamide: A career builder

My contribution to honoring Professor Kinam Park celebrates and resonates with his scholarly career in drug delivery, his commitment to encouraging the next generation(s), and his efforts to keep us focused on clinically effective formulations. To do this I take as my example, niclosamide, a small molecule protonophore that, uniquely, can "target" all cell membranes, both plasma and organelle. As such, it acts upstream of many cell pathways and so has the potential to affect many of the essential events that a cell, and particularly a diseased cell or other entities like a virus, use to stay alive and prosper. Literature shows that it has so far been discovered to positively influence (at least): cancer, bacterial and viral infection, metabolic diseases such as Type II diabetes, NASH and NAFLD, artery constriction, endometriosis, neuropathic pain, rheumatoid arthritis, sclerodermatous graft-versus-host disease, systemic sclerosis, Parkinson's, and COPD. With such a fundamental action and broad-spectrum activity, I believe that studying niclosamide in all its manifestations, discovering if and to what extent it can contribute positively to disease control (and also where it can't), formulating it as effective therapeutics, and testing them in preclinical and clinical trials is a career builder for our next generation(s). The article is divided into two parts: Part I introduces niclosamide and other proton shunts mainly in cancer and viral infections and reviews an exponentially growing literature with some concepts and physicochemical properties that lead to its proton shunt mechanism. Part II focuses on repurposing by reformulation of niclosamide. I give two examples of "carrier-free formulations", - one for cancer (as a prodrug therapeutic of niclosamide stearate for i.v. and other administration routes, exemplified by our recent work on Osteosarcoma in mice and canine patients), and the other as a niclosamide solution formulation (that could provide the basis for a preventative nasal spray and early treatment option for COVID19 and other respiratory virus infections). My goal is to excite and enthuse, encourage, and motivate all involved in the drug development and testing process in academia, institutes, and industry, to learn more about this interesting molecule and others like it. To enable such endeavors, I give many proposed ideas throughout the document, that have been stimulated and inspired by gaps in the literature, urgent needs in disease, and new studies arising from our own work. The hope is that, by reading through this document and studying the suggested topics and references, the drug delivery and development community will continue our lineage and benefit from our legacy to achieve niclosamide's potential as an effective contributor to the treatment and control of many diseases and conditions.

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).

Median effective dose of esketamine for intranasal premedication in children with congenital heart disease

BACKGROUND

Esketamine is commonly used as a premedication for its sedation effect. However, the proper dosage for intranasal use in children with congenital heart disease (CHD) has not been determined. This study aimed to estimate the median effective dose (ED₅₀) of esketamine for intranasal premedication in children with CHD.

METHODS

Thirty-four children with CHD who needed premedication in March 2021 were enrolled. Intranasal esketamine was initiated at a dose of 1 mg/kg. Based on the outcome of sedation in the previous patient, the dose for the subsequent patient was either increased or reduced by 0.1 mg/kg, which was adjusted between each child. Successful sedation was defined as a Ramsay Sedation Scale score ≥ 3 and Parental Separation Anxiety Scale score ≤ 2. The required ED₅₀ of esketamine was calculated using the modified sequential method. Non-invasive blood pressure, heart rate, saturation of peripheral oxygen, sedation onset time, and adverse reactions were recorded at 5 min intervals after drug administration.

RESULTS

The 34 children enrolled had a mean age of 22.5 ± 16.4 (4-54) months and a mean weight of 11.2 ± 3.6 (5.5-20.5) kg; American Society of Anesthesiologists classification I-III. The ED₅₀ of intranasal S(+)-ketamine (esketamine) required for preoperative sedation in pediatric patients with CHD was 0.7 (95% confidence interval: 0.54-0.86) mg/kg, and the mean sedation onset time was 16.39 ± 7.24 min. No serious adverse events, such as respiratory distress, nausea, and vomiting were observed.

CONCLUSIONS

The ED₅₀ of intranasal esketamine was 0.7 mg/kg, which was safe and effective for preoperative sedation in pediatric patients with CHD.

TRIAL REGISTRATION

The trial was registered in the Chinese Clinical Trial Registry Network (ChiCTR2100044551) on 24/03/2021.

Comparison of oral triclofos and intranasal midazolam and dexmedetomidine for sedation in children undergoing magnetic resonance imaging (MRI): an open-label, three-arm, randomized trial

The purpose of this study was to compare the efficacy of oral triclofos (TRI), intranasal midazolam (INM), and intranasal dexmedetomidine (IND) in achieving successful sedation in children undergoing MRI. This open-label, three-arm, randomized trial was conducted in a tertiary care teaching hospital over 18-month period. Children scheduled for MRI were enrolled. Rate of successful/adequate sedation was assessed using the Paediatric Sedation State Scale (PSSS). The primary outcome was the efficacy (successful sedation or sedation rate) of the three drugs. One-hundred and ninety-five children were included for the MRI procedure. IND was found to be superior in terms of achieving successful sedation. INM had a shorter onset and duration of sedation compared to IND and TRI, but with an increased failure rate (88.3%). Keeping INM as the reference group, it was found that the odds of sedation increased 4.1 times on changing from INM to IND (p < 0.01), and 2.26 times on changing from INM to TRI (p < 0.01). Adverse events included nasal discomfort (18.3%) in INM group; and self-limited tachycardia (4.6%) and hypotension (10.8%) in the IND group.

CONCLUSION

IND was more efficacious than INM or TRI for procedural sedation in children undergoing MRI without any significant adverse events.

CLINICAL TRIAL REGISTRATION

CTRI/2019/01/017257; date registered: 25/01/2019.

WHAT IS KNOWN

• Oral triclofos (TRI) and intranasal midazolam (INM) have been used for procedural sedation in children undergoing MRI with variable success; but the experience with intranasal dexmedetomidine (IND) is limited.

WHAT IS NEW

• IND provides more effective sedation compared to INM or TRI for procedural sedation in children undergoing MRI, without any significant adverse events.

What's New in Intravenous Anaesthesia? New Hypnotics, New Models and New Applications

New anaesthetic drugs and new methods to administer anaesthetic drugs are continually becoming available, and the development of new PK-PD models furthers the possibilities of using arget controlled infusion (TCI) for anaesthesia. Additionally, new applications of existing anaesthetic drugs are being investigated. This review describes the current situation of anaesthetic drug development and methods of administration, and what can be expected in the near future.

Strategies to Improve Drug Strength in Nasal Preparations for Brain Delivery of Low Aqueous Solubility Drugs

Intranasal administration is a promising route for brain drug delivery. However, it can be difficult to formulate drugs that have low water solubility into high strength intranasal solutions. Hence, the purpose of this work was to review the strategies that have been used to increase drug strength in intranasal liquid formulations. Three main groups of strategies are: the use of solubilizers (change in pH, complexation and the use cosolvents/surfactants); incorporation of the drugs into a carrier nanosystem; modifications of the molecules themselves (use of salts or hydrophilic prodrugs). The use of high amounts of cosolvents and/or surfactants and pH decrease below 4 usually lead to local adverse effects, such as nasal and upper respiratory tract irritation. Cyclodextrins and (many) different carrier nanosystems, on the other hand, could be safer for intranasal administration at reasonably high concentrations, depending on selected excipients and their dose. While added attributes such as enhanced permeation, sustained delivery, or increased direct brain transport could be achieved, a great effort of optimization will be required. On the other hand, hydrophilic prodrugs, whether co-administered with a converting enzyme or not, can be used at very high concentrations, and have resulted in a fast prodrug to parent drug conversion and led to high brain drug levels. Nevertheless, the choice of which strategy to use will always depend on the characteristics of the drug and must be a case-by-case approach.

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.

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.

Intranasal midazolam for the sedation of geriatric patients with care-resistant behaviour during essential dental treatment: An observational study

OBJECTIVES

To describe the efficacy and safety of intranasal midazolam for sedation during essential dental treatment of geriatric patients with major neurocognitive disorder (MND) and care-resistant behaviour (CRB).

BACKGROUND

Dental treatment is often impossible in geriatric MND patients with CRB. Intranasal midazolam may provide a non-invasive sedation method, but there is currently no information on its use in geriatric patients.

METHODS

In this observational study, we included geriatric patients with severe MND and CRB needing urgent dental treatment. Each patient received 5 mg midazolam intranasally. Agitation/sedation levels, heart rate, respiration rate and oxygen saturation were recorded at 5-minute intervals.

RESULTS

Thirty two patients were included. Mean age was 84 (±7) years. Mean (SD) time to treatment start was 13 (±5) minutes, and mean time to maximum sedation 17 (±11) minutes. Sedation was sufficient to enable dental treatment to be completed in 31 (97%) patients. Anxiolysis/light sedation occurred in 16 (50%) patients, and moderate to deep sedation occurred in 16 (50%) patients. No patients suffered from apnoea, although 3 patients required a chin-lift manoeuvre. Hypoxaemia occurred in 1 of these patients and in 2 other patients without airway obstruction. All patients recovered uneventfully. In a regression model, age, weight and other sedative medication use were found not to be associated with maximum sedation depth.

CONCLUSIONS

Of 5 mg intranasal midazolam facilitates treatment of geriatric patients with MND in the comfort of their own environment. More information is needed to guide titration to balance the desired sedation level and patient safety.

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.

Comparison of the Sedative Effect of Inhaled Nitrous Oxide and Intranasal Midazolam in Behavior Management and Pain Perception of Pediatric Patients: A Split-mouth Randomized Controlled Clinical Trial

Background

Management of children has always been a challenging task in the dental office, as many children exhibit extreme fear, apprehension, and anxiety toward dental procedures. Pharmacological means of behavior management such as sedation are now at the forefront. Midazolam and nitrous oxide are the commonly employed pharmacological agents for sedation in pediatric dentistry. Though each route has its advantages and disadvantages, we compared the effect of atomized intranasal midazolam (dosage 0.3 mg/kg body weight) and nitrous oxide oxygen sedation in evaluating the behavior of child, pain experienced during local anesthesia administration, sedation level, and patient's acceptance.

Materials and methods

A total of 35 (n = 35) anxious pediatric patients aged 4-7 years with negative and definitely negative behavioral rating were randomized to receive intranasal midazolam and inhalational nitrous oxide through mask. The overall behavior, alertness, and cry were recorded using Houpt rating scale while pain and sedation were assessed by face, legs, activity, cry, and consolability (FLACC) and Ellis sedation scores, respectively.

Results

The children who received intranasal midazolam sedation were calm, had less adverse effects, and had better acceptance of the drug. Both the techniques of sedation were found to be equally effective in terms overall behavior rating.

Conclusion

Intranasal midazolam was found to be as effective as nitrous oxide sedation for controlling behavior and providing adequate sedation in pediatric dental patients. It can also be an effective alternative for anxious patients who are unable to maintain the nitrous oxide mask throughout the dental procedure.

How to cite this article

Srinivasan NK, Karunagaran P, Panchal V, et al. Comparison of the Sedative Effect of Inhaled Nitrous Oxide and Intranasal Midazolam in Behavior Management and Pain Perception of Pediatric Patients: A Split-mouth Randomized Controlled Clinical Trial. Int J Clin Pediatr Dent 2021;14(S-2):S111-S116.

Tailoring Midazolam-Loaded Chitosan Nanoparticulate Formulation for Enhanced Brain Delivery via Intranasal Route

In the present study, midazolam (MDZ)-loaded chitosan nanoparticle formulation was investigated for enhanced transport to the brain through the intranasal (IN) route. These days, IN MDZ is very much in demand for treating life-threatening seizure emergencies; therefore, its nanoparticle formulation was formulated in the present work because it could substantially improve its brain targeting via the IN route. MDZ-loaded chitosan nanoparticles (MDZ-CSNPs) were formulated and optimized by the ionic gelation method and then evaluated for particle size, particle size distribution (PDI), drug loading (DL), encapsulation efficiency (EE), and in vitro release as well as in vitro permeation. The concentration of MDZ in the brain after the intranasal administration of MDZ-CSNPs (C_max 423.41 ± 10.23 ng/mL, tmax 2 h, and area under the curve from 0 to 480 min (AUC_0-480) of 1920.87 ng.min/mL) was found to be comparatively higher to that achieved following intravenous (IV) administration of MDZ solution (C_max 245.44 ± 12.83 ng/mL, t_max 1 h, and AUC_0-480 1208.94 ng.min/mL) and IN administration of MDZ solution (C_max 211.67 ± 12.82, t_max 2 h, and AUC_0-480 1036.78 ng.min/mL). The brain–blood ratio of MDZ-CSNPs (IN) were significantly greater at all sampling time points when compared to that of MDZ solution (IV) and MDZ (IN), which indicate that direct nose-to-brain delivery by bypassing the blood–brain barrier demonstrates superiority in brain delivery. The drug-targeting efficiency (DTE%) as well as nose-to-brain direct transport percentage (DTP%) of MDZ-CSNPs (IN) was found to be comparatively higher than that for other formulations, suggesting better brain targeting potential. Thus, the obtained results demonstrated that IN MDZ-CSNP has come up as a promising approach, which exhibits tremendous potential to mark a new landscape for the treatment of status epilepticus.

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

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-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 (TEAEs) were also evaluated.

RESULTS

In-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 (i.e., two puffs; range 2.5-15 mg) was administered within a median time from EEG seizure onset until in-MDZ application of 1.18 min [interquartile range (IQR) 1.27], while median time from clinical seizure onset until in-MDZ administration was 1.08 min (IQR 1.19). In-MDZ was given within 1 min 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 < 0.001) and generalized tonic-clonic seizure (Cox proportional-hazard model p = 0.0167) over a period of 24 h. The seizure-free timespan was doubled from a median of 5.0 h in controls to a median of 10.67 h 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 h as compared with when the same patient does not receive in-MDZ (hazard ratio 0.50; 95% CI 0.42-0.60; p < 0.01). In-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. In-MDZ can be administered very quickly by trained staff within 1-2 min after seizure onset. No major cardiocirculatory or respiratory adverse events were observed.

Midazolam: an essential palliative care drug

Midazolam is a commonly used benzodiazepine in palliative care and is considered one of the four essential drugs needed for the promotion of quality care in dying patients. Acting on the benzodiazepine receptor, it promotes the action of gamma-aminobutyric acid. Gamma-aminobutyric acid action promotes sedative, anxiolytic, and anticonvulsant properties. Midazolam has a faster onset and shorter duration of action than other benzodiazepines such as diazepam and lorazepam lending itself to greater flexibility in dosing than other benzodiazepines. The kidneys excrete midazolam and its active metabolite. Metabolism occurs in the liver by the P450 system. This article examines the pharmacology, pharmacodynamics, and clinical uses of midazolam in palliative care.

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.

Comparison of intranasal versus intravenous midazolam for management of status epilepticus in dogs: A multi-center randomized parallel group clinical study

Background

The intranasal (IN) route for rapid drug administration in patients with brain disorders, including status epilepticus, has been investigated. Status epilepticus is an emergency, and the IN route offers a valuable alternative to other routes, especially when these fail.

Objectives

To compare IN versus IV midazolam (MDZ) at the same dosage (0.2 mg/kg) for controlling status epilepticus in dogs.

Animals

Client‐owned dogs (n = 44) with idiopathic epilepsy, structural epilepsy, or epilepsy of unknown origin manifesting as status epilepticus.

Methods

Randomized parallel group clinical trial. Patients were randomly allocated to the IN‐MDZ (n = 21) or IV‐MDZ (n = 23) group. Number of successfully treated cases (defined as seizure cessation within 5 minutes and lasting for ≥10 minutes), seizure cessation time, and adverse effects were recorded. Comparisons were performed using the Fisher's exact and Wilcoxon rank sum tests with statistical significance set at α < .05.

Results

IN‐MDZ and IV‐MDZ successfully stopped status epilepticus in 76% and 61% of cases, respectively (P = .34). The median seizure cessation time was 33 and 64 seconds for IN‐MDZ and IV‐MDZ, respectively (P = .63). When the time to place an IV catheter was taken into account, IN‐MDZ (100 seconds) was superior (P = .04) to IV‐MDZ (270 seconds). Sedation and ataxia were seen in 88% and 79% of the dogs treated with IN‐MDZ and IV‐MDZ, respectively.

Conclusions and Clinical Importance

Both routes are quick, safe, and effective for controlling status epilepticus. However, the IN route demonstrated superiority when the time needed to place an IV catheter was taken into account.

Recent Advances and Novel Approaches for Nose to Brain Drug Delivery for Treatment of Migraine

Background:

Nasal drug delivery has been used since ancient times for therapeutic and recreational purposes. For the last decades, nasal drug delivery has been extended for drug delivery to the brain. Therefore, it is important to understand the several physiological and physicochemical factors of the nose for brain drug delivery.

Objective:

A major highlight of the present review article is the several aspects of the nose to brain delivery for migraine treatment. This review will help to understand different factors which are needed to be considered for intra-nasal formulations to achieve the desired therapeutic effects.

Method:

There are different drug delivery routes available for migraine treatment. Nasal route of administration may be optimal for migraine treatment which has better drug concentration in the brain. These approaches may be associated with limiting the adverse effects of drug therapeutics.

Results:

A list of total FDA approved approaches has been provided. Novel approaches used for drug targeting to get maximum drug concentration in the brain have been highlighted. Several novel drug delivery approaches such as nanoparticle, nanoemulsion, microspheres, etc. have been reported and better therapeutic effects have been observed. Among the novel approaches, some of them are currently under either Phase II or Phase III development but may prove to offer better clinical effects. These approaches would become the alternate choice for migraine treatment with patients experiencing symptoms consistent with gastrointestinal dysfunction associated with migraine.

Conclusion:

Intra-nasal administration of drugs for migraine treatment may offer an interesting alternative for achieving therapeutic effects of drugs which are comparable to the parenteral route. Nasal drug delivery can be an alternative route of drug administration for migraine treatment to achieve better bioavailability.

Safety and sedative effect of intranasal dexmedetomidine in mandibular third molar surgery: a systematic review and meta-analysis

Objective

The focus of this meta-analysis was to assess the sedative effect and safety of intranasal dexmedetomidine (Dex) in mandibular third molar surgery.

Methods

The PubMed/Medline, Web of Science, Cochrane Library, and China National Knowledge Infrastructure databases were searched for studies published until May 1, 2018. Eligible studies were restricted to randomized controlled trials (RCTs) and controlled clinical trials. The evaluation indicators mainly included the bispectral index, observer assessment of alertness/sedation scale, systolic blood pressure, and heart rate. Data for each period in the Dex and control groups were pooled to evaluate its sedative effect and safety.

Results

Five RCTs met the inclusion criteria. This study included 363 patients: 158 patients received intranasal inhalation of Dex before surgery, and 158 patients were negative controls. The pooled results showed a good sedative effect during tooth extraction when intranasal inhalation of Dex was performed 30 minutes before third molar extraction (assessment of alertness/sedation, Dex vs control SMD −1.20, 95% CI −1.73 to −0.67, I²=0, P=0.95; bispectral index, Dex vs control SMD −11.68, 95% CI −19.49 to −3.87, I²=89%; P=0.0001), and parameters returned to normal within 90 minutes after inhalation. During the operation, blood pressure and heart rate decreased to some extent, but the decreases did not exceed 20% of the baseline, and all patients returned to normal conditions within 90 minutes after inhalation.

Conclusion

Intranasal inhalation of Dex 30 minutes before third molar extraction can provide a good sedative effect, and large-sample multicenter RCTs are needed to evaluate the analgesic effect of Dex.

Comparative Study of Oral Midazolam Syrup and Intranasal Midazolam Spray for Sedative Premedication in Pediatric Surgeries

Introduction:

Midazolam is a water-soluble benzodiazepine which is frequently administered by intravenous and oral routes. Its nasal spray has become recently available.

Materials and Methods:

In this study, after obtaining clearance from the ethical committe, 66 patients between the age group of 4 and 10 years comparable in demographic variables were randomly allocated into two groups of 33 each. Group “O” received oral midazolam (0.5 mg/kg) 20 min before induction. Group “N” received intranasal midazolam (0.2 mg/kg) 20 min before induction. The heart rate and blood pressure (systolic, diastolic, and mean) and oxygen saturation (SPO₂) were recorded.

Statistical Analysis Used:

The statistical analysis was done using SPSS (Statistical Package for the Social Sciences) version 15.0 software. The values were represented in number (%) and mean±sd.

Results:

Satisfactory sedation scores were better in nasal spray group than oral group. Satisfactory ease of induction scores, recovery times, and postanesthesia recovery scores were better in the nasal spray group than in the oral group.

Conclusion:

Nasal midazolam spray is acceptable and is a good alternative to oral midazolam as premedication in the pediatric population.

Delivery of End-of-Life Care in Patients Requesting Withdrawal of a Left Ventricular Assist Device Using Intranasal Opioids and Benzodiazepines

With the increasing prevalence of the left ventricular assist device (LVAD) in patients with end-stage cardiomyopathies, an increasing number of these patients are dying of noncardiac conditions. It is likely that the palliative care clinician will have an ever-increasing role in managing end of life for patients with LVADs, including discontinuation of LVAD support. There exists a paucity of literature describing strategies for effective delivery of palliative care in patients requesting discontinuation of LVAD therapy. Here, we present a case of a patient with metastatic cancer who requested LVAD discontinuation. Because of practical concerns and patient preference, the patient did not have intravenous (IV) access and medications requiring IV administration could not be used. Therefore, a strategy using intranasal midazolam and sufentanil was applied, the LVAD was deactivated, and the patient died comfortably. This case is, to our knowledge, the first to describe a strategy for delivery of palliative care in patients requesting discontinuation of LVAD support, particularly in the absence of IV access. Such a strategy may be applicable to patients wishing to die at home, and therefore allow greater latitude for patients and clinicians in their approach to the end of life.

Plasma concentration based response surface model predict better than effect-site concentration based model for wake-up time during gastrointestinal endoscopy sedation

BACKGROUND

Sedation for esophagogastroduodenoscopy (EGD) and colonoscopy is characterized by rapid patient induction and emergence. The drugs midazolam and alfentanil have long been used for procedural sedation; however, the relationship between plasma or effect-site concentrations (Cp or Ce, respectively) and emergence remains unclear. The aim of this study is to develop patient wake-up prediction models for both Cp and Ce using response surface modeling, a pharmacodynamics tool for assessing patients' responses.

METHODS

The Observer's Alertness/Sedation (OAA/S) score was used to monitor sedation depth during the examinations. Concentration pairs of midazolam and alfentanil were calculated for each of Cp and Ce using pharmacokinetic simulation software. Response surface models were developed using the Greco construct. Temporal analysis was done by comparing model-predicted wake-up time with true patient wake-up time.

RESULTS

Thirty-three patients with an average body mass index of 21.85 ± 2.3 kg/m² were pooled for analysis. The average duration of examination were 2.9 ± 1.4 min for EGD and 6.6 ± 2.7 min for colonoscopy. Seventy-five concentration pairs of midazolam and alfentanil were obtained for each Cp and Ce. The Cp-based Greco response surface model showed significant synergy between midazolam and alfentanil and was a better predictor of patient wake-up time, with an average deviation of 1.0 ± 3.9 min, while the Ce model show time deviation greater than 20 min.

CONCLUSION

The early phases of drug distribution are unique and complicated by nonsteady-state concentrations, and our study revealed that Ce-based wake-up time prediction is more difficult under these circumstances.

Adverse events and satisfaction with use of intranasal midazolam for emergency department procedures in children

PURPOSE

Procedural sedation is commonly performed in the emergency department (ED). Having safe and fast means of providing sedation and anxiolysis to children is important for the child's tolerance of the procedure, parent satisfaction and efficient patient flow in the ED.

OBJECTIVE

To evaluate fasting times associated with the administration of intranasal midazolam (INM) and associated complications. Secondary objectives included assessing provider and caregiver satisfaction scores.

METHODS

A prospective observational study was conducted in children presenting to an urban pediatric emergency department who received INM for anxiolysis for a procedure or imaging. Data collected included last solid and liquid intake, procedure performed, sedation depth, adverse events and parent and provider satisfaction.

RESULTS

112 patients were enrolled. The mean age was 3.8 years. There were no adverse events experienced by any patients. Laceration repair was the most common reason for INM use. The median depth of sedation was 2.0 (cooperative/tranquil). The median liquid NPO time was 172.5 min and the median NPO time for solids was 194.0 min. 29.8% were NPO for liquids ≤2 h and 62.5% were NPO for solids ≤2 h. Parent and provider satisfaction was high: 90.4% of parents' and 88.4% of providers' satisfaction scores were a 4 or 5 on a 5 point Likert scale.

CONCLUSION

Our data suggest that short NPO of both solids and liquids are safe for the use of INM. Additionally, parent and provider satisfaction scores were high with the use of INM.

Intranasal sedatives in pediatric dentistry

OBJECTIVES

To identify the intranasal (IN) sedatives used to achieve conscious sedation during dental procedures amongst children.

METHODS

A literature review was conducted by identifying relevant studies through searches on Medline. Search included IN of midazolam, ketamine, sufentanil, dexmedetomidine, clonidine, haloperidol, and loranzepam. Studies included were conducted amongst individuals below 18 years, published in English, and were not restricted by year. Exclusion criteria were articles that did not focus on pediatric dentistry. 

RESULTS

Twenty studies were included. The most commonly used sedatives were midazolam, followed by ketamine and sufentanil. Onset of action for IN midazolam was 5-15 minutes (min), however, IN ketamine was faster (mean 5.74 min), while both IN sufentanil (mean 20 min) and IN dexmedetomidine (mean 25 min) were slow in comparison. Midazolam was effective for modifying behavior in mild to moderately anxious children, however, for more invasive or prolonged procedures, stronger sedatives, such as IN ketamine, IN sufentanil were recommended. In addition, ketamine fared better in overall success rate (89%) when compared with IN midazolam (69%). Intranasal dexmedetomidine was only used as pre-medication amongst children. While its' onset of action is longer when compared with IN midazolam, it produced deeper sedation at the time of separation from the parent and at the time of anesthesia induction.

CONCLUSION

Intranasal midazolam, ketamine, and sufentanil are effective and safe for conscious sedation, while intranasal midazolam, dexmedetomidine, and sufentanil have proven to be effective premedications.

Evaluating Clinical Effectiveness and Pharmacokinetic Profile of Atomized Intranasal Midazolam in Children Undergoing Laceration Repair

BACKGROUND

Atomized intranasal midazolam is a common adjunct in pediatrics for procedural anxiolysis. There are no previous studies of validated anxiety scores with pharmacokinetic data to support optimal procedure timing.

OBJECTIVES

We describe the clinical and pharmacokinetic profile of atomized intranasal midazolam in children presenting for laceration repair.

METHODS

Children 11 months to 7 years of age and weighing <26 kg received 0.4 mg/kg of atomized intranasal midazolam for simple laceration repair. Blood samples were obtained at 3 time points in each patient, and the data were fit with a 1-compartment model. Patient anxiety was rated with the Observational Scale of Behavioral Distress. Secondary outcomes included use of adjunctive medications, successful completion of procedure, and adverse events.

RESULTS

Sixty-two subjects were enrolled, with a mean age of 3.3 years. The median time to peak midazolam concentration was 10.1 min (interquartile range 9.7-10.8 min), and the median time to the procedure was 26 min (interquartile range 21-34 min). There was a trend in higher Observational Scale of Behavioral Distress scores during the procedure. We observed a total of 2 adverse events, 1 episode of vomiting (1.6%) and 1 paradoxical reaction (1.6%). Procedural completion was successful in 97% of patients.

CONCLUSIONS

Atomized intranasal midazolam is a safe and effective anxiolytic to facilitate laceration repair. The plasma concentration was >90% of the maximum from 5 to 17 min, suggesting this as an ideal procedural timeframe after intranasal midazolam administration.

Combined Catalase and ADH Inhibition Ameliorates Ethanol-Induced Myocardial Dysfunction Despite Causing Oxidative Stress in Conscious Female Rats

BACKGROUND

Ethanol (EtOH)-evoked oxidative stress, which contributes to myocardial dysfunction in proestrus rats, is mediated by increases in NADPH oxidase (Nox) activity, malondialdehyde (MDA), and ERK1/2 phosphorylation. Whether these biochemical responses, which are triggered by alcohol-derived acetaldehyde in noncardiac tissues, occur in proestrus rats' hearts remains unknown. Therefore, we elucidated the roles of alcohol dehydrogenase (ADH), cytochrome P4502E1 (CYP2E1), and catalase, which catalyze alcohol oxidation to acetaldehyde, in these alcohol-evoked biochemical and hemodynamic responses in proestrus rats.

METHODS

Conscious proestrus rats prepared for measurements of left ventricular (LV) function and blood pressure (BP) received EtOH (1.5 g/kg, intravenous [i.v.] infusion over 30 minutes) or saline 30 minutes after an ADH and CYP2E1 inhibitor, 4-methylpyrazole (4-MP) (82 mg/kg, intraperitoneal), a catalase inhibitor, 3-AT (0.5 g/kg, i.v.), their combination, or vehicle. LV function and BP were monitored for additional 60 minutes after EtOH or saline infusion before collecting the hearts for ex vivo measurements of LV reactive oxygen species (ROS), Nox activity, MDA, and ERK1/2 phosphorylation.

RESULTS

EtOH reduced LV function (dP/dt_max and LV developed pressure) and BP, and increased cardiac Nox activity, ROS and MDA levels, and ERK1/2 phosphorylation. Either inhibitor partially, and their combination significantly, attenuated these responses despite the substantially higher blood EtOH level, and the increased cardiac oxidative stress and reduced BP caused by 3-AT alone or with 4-MP. The inhibitors reduced cardiac MDA level and reversed EtOH effect on cardiac and plasma MDA.

CONCLUSIONS

EtOH oxidative metabolism plays a pivotal role in the EtOH-evoked LV oxidative stress and dysfunction in proestrus rats. Notably, catalase inhibition (3-AT) caused cardiac oxidative stress and hypotension.

Pharmacokinetics, pharmacodynamics, and tolerability of USL261, midazolam nasal spray: Randomized study in healthy geriatric and non-geriatric adults

AIM

Characterize pharmacokinetics, pharmacodynamics, and safety/tolerability of USL261 in geriatric adults to inform its potential for treating bouts of increased seizure activity.

METHODS

Phase 1, randomized, double-blind, 2-way crossover study in healthy geriatric (≥65years; n=18) and non-geriatric (18-40years; n=12) adults evaluated single USL261 doses (2.5 and 5.0mg) administered intranasally. Pharmacokinetic parameters were estimated for midazolam and 1-hydroxymidazolam (active metabolite), including area under the plasma concentration-time curve (AUC), maximum plasma concentration (C_max), time to C_max (T_max), and half-life (t_1/2). Stanford Sleepiness Scale and Observer's Assessment of Alertness/Sedation assessed sedation; Digit-Symbol Substitution Test assessed psychomotor performance.

RESULTS

Midazolam exposure and plasma concentrations were higher in geriatric versus non-geriatric adults (geometric mean AUC_0-∞ [ng*h/mL] 2.5mg: 70 vs 54, respectively; 5.0mg: 157 vs 110; C_max [ng/mL] 2.5mg: 27.1 vs 22.5; 5.0mg: 55.8 vs 46.1). USL261 was rapidly absorbed, with no differences in median T_max (14.5-17.3min); mean t_1/2 was longer in geriatric subjects. Similar age-related trends were observed for 1-hydroxymidazolam. Mean maximum observed pharmacodynamic effects were not significantly different between age groups, though were more pronounced following 5.0 versus 2.5mg (P<.05); return to baseline was generally achieved within 4h. USL261 was generally well tolerated, with similar adverse event rates between age groups.

CONCLUSIONS

Despite increased midazolam exposure in geriatric subjects, there were no differences between age groups in pharmacodynamic effects or adverse event rates. USL261 was rapidly absorbed and pharmacodynamic effects returned to baseline within ~4h, regardless of age. Dose-dependent pharmacokinetic and maximum pharmacodynamic effects were observed. Overall, pharmacokinetic findings for USL261 were similar to studies evaluating intravenous midazolam, whereas pharmacodynamic effects were less pronounced in the elderly than previously reported.

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.

Comparison of preanesthetic sedation in pediatric patients with oral and intranasal midazolam

BACKGROUND AND AIMS

Preoperative anxiety in children leading to postoperative negative changes and long-term behavioral problems needs better preanesthetic sedation. Across the world, midazolam is the most commonly used premedicant in pediatric patients. The fact that no single route has achieved universal acceptance for its administration suggests that each route has its own merits and demerits. This study compares oral midazolam syrup and intranasal midazolam spray as painless and needleless systems of drug administration for preanesthetic sedation in children.

MATERIAL AND METHODS

With randomization, Group O (30 children): Received oral midazolam syrup 0.5 mg/kg and Group IN (30 children): Received intranasal midazolam spray 0.2 mg/kg. Every child was observed for acceptance of drug, response to drug administration, sedation scale, separation score, acceptance to mask, recovery score and side effects of drug. Data were analyzed using Student's t-test, standard error of the difference between two means and Chi-square test.

RESULTS

In Group O and IN, 15/30 children (50%) and 7/30 children (23%) accepted drug easily (P < 0.05); 4/22 children (18%) in Group O and 11/20 children (55%) in Group IN cried after drug administration (P < 0.05). In both the groups, sedation at 20 min after premedication (Group O [80%] 24/30 vs. Group IN [77%] 23/30), parental separation and acceptance to mask were comparable (P > 0.05); 12/30 children (40%) in Group IN showed transient nasal irritation.

CONCLUSION

Oral midazolam and intranasal midazolam spray produce similar anxiolysis and sedation, but acceptance of drug and response to drug administration is better with oral route.

Status Epilepticus: What's New?

The emergent evaluation and treatment of generalized convulsive status epilepticus presents challenges for emergency physicians. This disease is one of the few in which minutes can mean the difference between life and significant morbidity and mortality. It is imperative to use parallel processing and have multiple treatment options planned in advance, in case the current treatment is not successful. There is also benefit to exploring, or initiating, treatment algorithms to standardize the care for these critically ill patients.

Population Pharmacokinetics of an Intranasally Administered Combination of Oxymetazoline and Tetracaine in Healthy Volunteers

The primary objective of the current investigation was to establish the pharmacokinetic characteristics of oxymetazoline and tetracaine's primary metabolite, para-butylaminobenzoic acid (PBBA), after the intranasal administration of oxymetazoline/tetracaine. Thirty-six subjects contributing a total of 1791 plasma concentration results from 2 open-label trials were utilized. Model development was achieved using data from the second trial (N = 24) in which 0.3 mg oxymetazoline/18 mg tetracaine was administered. External model validation utilized data from the first trial (N = 12), which included doses of 0.3 mg oxymetazoline/18 mg tetracaine and 0.6 mg oxymetazoline/36 mg tetracaine. Oxymetazoline and PBBA dispositions were described by a 2-compartment model with first-order absorption. An allometric model for body weight was included on volumes and clearances to describe unexplained between-subject variability. The final oxymetazoline parameter estimates were k_a 4.41 h^-1 ; peripheral volume 418 L; clearance 66.4 L/h; central volume 6.97 L; and intercompartmental clearance 419 L/h for a 70-kg subject. The final PBBA parameter estimates were k_a 8.51 h^-1 ; peripheral volume 32.0 L; clearance 16.7 L/h; central volume 29.8 L; and intercompartmental clearance 2.43 L/h for a 70-kg subject. Between-subject variability ranged from 14% to 39% for oxymetazoline and from 10% to 94% for PBBA.

A review of intranasal formulations for the treatment of seizure emergencies

Epileptic seizure emergencies are life-threatening conditions, which in their most severe form, status epilepticus, have a high mortality rate if not quickly terminated. Treatment requires rapid delivery of anti-epileptics such as benzodiazepines to the brain. The nasal route is attractive due to its non-invasiveness, potential for direct nose to brain delivery, high vascularity, relatively large absorptive surface area, and avoidance of intestinal/liver metabolism. However, the limited volume of the nasal cavity and poor water solubility of anti-epileptics restrict absorption, leading to insufficient therapeutic brain levels. This review covers various formulation approaches adopted to improve nasal delivery of drugs, especially benzodiazepines, used to treat seizure emergencies. Other general topics such as nasal anatomy, challenges to nasal delivery, and drug/formulation considerations for nose to brain delivery are also discussed.

Safety and efficacy of intranasally administered medications in the emergency department and prehospital settings

PURPOSE

The safety and efficacy of medications that may be administered via the intranasal route in adult patients in the prehospital and emergency department (ED) settings are reviewed.

SUMMARY

When medications of appropriate molecular character and concentration are delivered intranasally, they are quickly transported across this capillary network and delivered to the systemic circulation, thereby avoiding the absorption-limiting effects of first-pass metabolism. Therapeutic drug concentrations are rapidly attained in the cerebrospinal fluid, making intranasal administration a very effective mode of delivery. To optimize the bioavailability of intranasally administered drugs, providers must minimize the barriers to absorption, minimize the volume by maximizing the concentration, maximize the absorptive surface of the nasal mucosa, and use a delivery system that maximizes drug dispersion and minimizes drug runoff. Medications can be instilled into the nasal cavity with syringes or droppers by applying a few drops at a time or via atomization. The intranasal route of administration may be advantageous for patients who require analgesia, sedation, anxiolysis, termination of seizures, hypoglycemia management, narcotic reversal, and benzodiazepine reversal in the ED or prehospital settings. Medications that have been studied in the adult population include fentanyl, sufentanil, hydromorphone, ketamine, midazolam, haloperidol, naloxone, flumazenil, and glucagon. The available data do indicate, however, that intranasal administration may be a safe, effective, and well tolerated route of administration.

CONCLUSION

Based on the published literature, intranasal administration of fentanyl, sufentanil, ketamine, hydromorphone, midazolam, haloperidol, naloxone, glucagon, and, in limited cases, flumazenil may be a safe, effective, and well-tolerated alternative to intramuscular or intravenous administration in the prehospital and ED settings.

Naloxone without the needle - systematic review of candidate routes for non-injectable naloxone for opioid overdose reversal

INTRODUCTION

Deaths from opioid overdose can be prevented through administration of the antagonist naloxone, which has been licensed for injection since the 1970s. To support wider availability of naloxone in community settings, novel non-injectable naloxone formulations are being developed, suitable for emergency use by non-medical personnel.

OBJECTIVES

1) Identify candidate routes of injection-free naloxone administration potentially suitable for emergency overdose reversal; 2) consider pathways for developing and evaluating novel naloxone formulations.

METHODS

A three-stage analysis of candidate routes of administration was conducted: 1) assessment of all 112 routes of administration identified by FDA against exclusion criteria. 2) Scrutiny of empirical data for identified candidate routes, searching PubMed and WHO International Clinical Trials Registry Platform using search terms "naloxone AND [route of administration]". 3) Examination of routes for feasibility and against the inclusion criteria.

RESULTS

Only three routes of administration met inclusion criteria: nasal, sublingual and buccal. Products are currently in development and being studied. Pharmacokinetic data exist only for nasal naloxone, for which product development is more advanced, and one concentrated nasal spray was granted licence in the US in 2015. However, buccal naloxone may also be viable and may have different characteristics.

CONCLUSION

After 40 years of injection-based naloxone treatment, non-injectable routes are finally being developed. Nasal naloxone has recently been approved and will soon be field-tested, buccal naloxone holds promise, and it is unclear what sublingual naloxone will contribute. Development and approval of reliable non-injectable formulations will facilitate wider naloxone provision across the community internationally.

Cytotoxic Effects of Intranasal Midazolam on Nasal Mucosal Tissue

The aim of this experimental study was to investigate the cytotoxic effects of intranasal midazolam on nasal mucosal tissue in rats. Forty healthy rats were randomly divided into 5 groups. Group 1 (n = 8) was the control group, group 2 (n = 8) received intranasal saline, group 3 (n = 8) received intranasal midazolam, group 4 (n = 8) received intraperitoneal saline, and group 5 received intraperitoneal midazolam (n = 8). Midazolam and saline were administered via intraperitoneal and intranasal routes at doses of 200 μg/kg. Nasal septal mucosal stripe tissues were removed at the 6th hour. All materials were evaluated according to Ki67 and p53 staining to evaluate proliferation and apoptosis, respectively, and hemotoxylin and eosin staining was performed for histopathology evaluation. Ki67 values and inflammation in group 3 were statistically higher compared to group 1, group 2, and group 4. P53 values in group 3 were statistically higher compared to group 1. Assessment of subepithelial edema between group 3 and the other groups revealed no statistically significant differences. Assessment of cilia loss between group 3 and group 1, group 2, and group 4 revealed no statistically significant difference. The evaluation of goblet cell loss between group 3 and group 1 revealed a statistically significant difference. Intranasal midazolam had adverse effects on nasal mucosa. However, intranasal midazolam is as safe as systemic midazolam administration with respect to nasal mucosa.

Mechanistic Modeling to Predict Midazolam Metabolite Exposure from In Vitro Data

Methods to predict the pharmacokinetics of drugs in humans from in vitro data have been established, but corresponding methods to predict exposure to circulating metabolites are unproven. The objective of this study was to use in vitro methods combined with static and dynamic physiologically based pharmacokinetic (PBPK) models to predict metabolite exposures, using midazolam and its major metabolites as a test system. Intrinsic clearances (CLint) of formation of individual metabolites were determined using human liver microsomes. Metabolic CLintof hydroxymidazolam metabolites via oxidation and glucuronidation were also determined. Passive diffusion intrinsic clearances of hydroxymidazolam metabolites were determined using sandwich cultured human hepatocytes and the combination of this term along with the metabolic CLint, and liver blood flow was used to estimate the fraction of the metabolite that can enter the systemic circulation after formation in the liver. The metabolite/parent drug area under the plasma concentration-time curve ratio (AUCm/AUCp) was predicted using a static model relating the fraction of midazolam clearance to each metabolite, the clearance rates of midazolam and hydroxymidazolam metabolites, and the availability of the metabolites. Additionally, the human disposition of midazolam metabolites was simulated using a SimCYP PBPK model. Both approaches yielded AUCm/AUCpratios that were in agreement with the in vivo ratios. This study shows that in vivo midazolam metabolite exposure can be predicted from in vitro data and PBPK modeling. This study emphasized the importance of metabolite systemic availability from its tissue of formation, which remains a challenge to quantitative prediction.

A randomised, double-blind controlled trial of intranasal midazolam for the palliation of dyspnoea in patients with life-limiting disease

PURPOSE

Anxiety is a major component of breathlessness and is often palliated with benzodiazepines. Midazolam is a short-acting water-soluble benzodiazepine with a rapid onset of action and short half-life. Intranasal midazolam had been shown to be of marked clinical benefit in an uncontrolled pilot study for the control of dyspnoea. A blinded randomised controlled study was therefore undertaken across four Australasian palliative care services.

METHODS

All participants received six numbered study nasal spray (SNS) bottles, three of which contained midazolam and three placebo. They were instructed to use one SNS bottle on each day they were breathless, for 6 days within 2 weeks. Dyspnoea scores were recorded before and at set time intervals following the first use of each SNS bottle.

RESULTS

Across all SNS bottles, the maximum change of 2.1 on an 11-point numerical rating scale was seen at 60 min. There was no difference in dyspnoea score between the two arms. Approximately 50 % of participants in each arm had a positive response (i.e. ≥2 point change in dyspnoea score from baseline). Anxiety scores at baseline were low. The most common adverse event was local nasal reactions.

CONCLUSION

Intranasal midazolam had no clinical benefit over intranasal placebo for the control of dyspnoea. The low level of anxiety at baseline and dose of active drug delivered may have been important factors. Many participants found the SNS bottles to be a challenging mode of drug delivery. This study confirms the importance of placebo-controlled trials for defining best clinical practise.

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.

Treatment of Generalized Convulsive Status Epilepticus in Pediatric Patients

Generalized convulsive status epilepticus (GCSE) is one of the most common neurologic emergencies and can be associated with significant morbidity and mortality if not treated promptly and aggressively. Management of GCSE is staged and generally involves the use of life support measures, identification and management of underlying causes, and rapid initiation of anticonvulsants. The purpose of this article is to review and evaluate published reports regarding the treatment of impending, established, refractory, and super-refractory GCSE in pediatric patients.

Effect of multiple intravenous doses of lanicemine (AZD6765) on the pharmacokinetics of midazolam in healthy subjects

The objectives of the present study were to evaluate safety and tolerability as well as the effects of multiple doses of lanicemine on the pharmacokinetics of a CYP3A substrate, midazolam. A total of 46 healthy volunteers were enrolled in the open-label, fixed-sequence, nonrandomized study. All volunteers received an oral dose of 5 mg of midazolam alone or after 6 days of 150 mg daily intravenous infusion of lanicemine. Lanicemine reached a plasma Cmax of 1.51 μg/mL after 150 mg daily dosing to steady state. The geometric mean CL, Vss, and t1/2 of lanicemine were 8.1 L/h, 122.0 L, and 10.4 hours, respectively. The geometric least-squares mean ratios and 90% confidence intervals for midazolam AUC0- ∞ , and Cmax were within the 80% to 125% limits when lanicemine plus midazolam treatment was compared with midazolam alone, demonstrating that daily dosing with 150 mg of lanicemine for 6 days had no effect on CYP3A activity. Comprehensive physiologically based pharmacokinetic modeling using in vitro and in silico findings also indicated lanicemine would have little impact on the pharmacokinetics of CYP3A substrate, such as midazolam. In addition, lanicemine and midazolam administered alone or in combination were generally safe and well tolerated.