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

Treatment of agitation in terminally ill patients with intranasal midazolam versus subcutaneous midazolam: study protocol for a randomised controlled open-label monocentric trial (MinTU Study)

BACKGROUND

Intranasal (i.n.) drug application is a widely known and low-invasive route of administration that may be able to achieve rapid symptom control in terminally ill patients. According to the German S3 guideline "Palliative care for patients with incurable cancer", benzodiazepines, such as midazolam, are recommended for the treatment of terminal agitation. To the best of our knowledge there is no evidence for i.n. midazolam in terminally ill patients. We aim to assess the use of i.n. midazolam as an alternative to subcutaneous administration of the drug.

METHODS

In this monocentric, randomised, controlled, open-label investigator initiated trial, n = 60 patients treated at the palliative care unit of a University Hospital will be treated with 5 mg midazolam i.n. versus 5 mg subcutaneous (s.c.) midazolam in the control arm when terminal agitation occurs (randomly assigned 1:1). The estimated recruitment period is 18 months. Treatment efficacy is defined as an improvement on the Richmond Agitation Sedation Scale (Palliative Version) (RASS-PAL) and a study specific numeric rating scale (NRS) before and after drug administration. Furthermore, plasma concentration determinations of midazolam will be conducted at t1 = 0 min, t2 = 5 min, and t3 = 20 min using liquid chromatography/mass spectrometry (LC-MS). The primary objective is to demonstrate non-inferiority of midazolam i.n. in comparison to midazolam s.c. for the treatment of agitation in terminally ill patients.

DISCUSSION

Midazolam i.n. is expected to achieve at least equivalent reduction of terminal agitation compared to s.c. administration. In addition, plasma concentrations of midazolam i.n. are not expected to be lower than those of midazolam s.c. and the dynamics of the plasma concentration with an earlier increase could be beneficial.

TRIAL REGISTRATION

German Clinical Trials Registry DRKS00026775, registered 07.07.2022, Eudra CT No.: 2021-004789-36.

Genetic polymorphisms are associated with individual susceptibility to dexmedetomidine

Introduction: Dexmedetomidine (DXM) is widely used as an adjuvant to anesthesia or a sedative medicine, and differences in individual sensitivity to the drug exist. This study aimed to investigate the effect of genetic polymorphisms on these differences. Methods: A total of 112 patients undergoing hand surgery were recruited. DXM 0.5 μg/kg was administered within 10 min and then continuously injected (0.4 μg/kg/h). Narcotrend index, effective dose and onset time of sedation, MAP, and HR were measured. Forty-five single nucleotide polymorphisms (SNPs) were selected for genotype. Results: We observed individual differences in the sedation and hemodynamics induced by DXM. ABCG2 rs2231142, CYP2D6 rs16947, WBP2NL rs5758550, KATP rs141294036, KCNMB1 rs11739136, KCNMA1 rs16934182, ABCC9 rs11046209, ADRA2A rs1800544, and ADRB2 rs1042713 were shown to cause statistically significant (p < 0.05) influence on the individual variation of DXM on sedation and hemodynamics. Moreover, the multiple linear regression analysis indicated sex, BMI, and ADRA2A rs1800544 are statistically related to the effective dose of DXM sedation. Discussion: The evidence suggests that the nine SNPs involved in transport proteins, metabolic enzymes, and target proteins of DXM could explain the individual variability in the sedative and hemodynamic effects of DXM. Therefore, with SNP genotyping, these results could guide personalized medication and promote clinical and surgical management.

Fit for purpose of on-the-road driving and simulated driving: A randomised crossover study using the effect of sleep deprivation

INTRODUCTION

Drivers should be aware of possible impairing effects of alcohol, medicinal substance, or fatigue on driving performance. Such effects are assessed in clinical trials, including a driving task or related psychomotor tasks. However, a choice between predicting tasks must be made. Here, we compare driving performance with on-the-road driving, simulator driving, and psychomotor tasks using the effect of sleep deprivation.

METHOD

This two-way cross over study included 24 healthy men with a minimum driving experience of 3000km per year. Psychomotor tasks, simulated driving, and on-the-road driving were assessed in the morning and the afternoon after a well-rested night and in the morning after a sleep-deprived night. Driving behaviour was examined by calculating the Standard Deviation of Lateral Position (SDLP).

RESULTS

SDLP increased after sleep deprivation for simulated (10cm, 95%CI:6.7-13.3) and on-the-road driving (2.8cm, 95%CI:1.9-3.7). The psychomotor test battery detected effects of sleep deprivation in almost all tasks. Correlation between on-the-road tests and simulator SDLP after a well-rested night (0.63, p < .001) was not present after a night of sleep deprivation (0.31, p = .18). Regarding the effect of sleep deprivation on the psychomotor test battery, only adaptive tracking correlated with the SDLP of the driving simulator (-0.50, p = .02). Other significant correlations were related to subjective VAS scores.

DISCUSSION

The lack of apparent correlations and difference in sensitivity of performance of the psychomotor tasks, simulated driving and, on-the-road driving indicates that the tasks may not be interchangeable and may assess different aspects of driving behaviour.

Perioperative Low Dose Dexmedetomidine and Its Effect on the Visibility of the Surgical Field for Middle Ear Microsurgery: A Randomised Controlled Trial

Background and Purpose: There are many benefits of administering dexmedetomidine perioperatively. The pharmacokinetics (PK) and pharmacodynamics (PD) of intravenous, intranasal and oral dexmedetomidine that was administered before anesthesia were compared in this study, and the effects of dexmedetomidine on the surgical field visibility in tympanoplasty was evaluated. Methods: A single-blind, randomized controlled trial was conducted in a university-affiliated hospital where 45 patients who underwent tympanoplasty under general anesthesia were randomly allocated into three groups. Dexmedetomidine was administered by intravenous infusion at 0.8 μg.kg^-1 for 10 min, intranasal instillation at a drop rate of 1 μg.kg^-1 and oral intake at 4 μg.kg^-1 ten minutes before the induction of anesthesia. The PK and PD of dexmedetomidine after a single low dose administration and its effect on the surgical field in tympanoplasty were analysed. Results: A plasma concentration of dexmedetomidine of 220 pg/ml was achieved immediately after intravenous infusion and at 13.2 and 70.3 min for intranasal and oral administration, respectively. Dexmedetomidine decreased the heart rate (HR) and mean arterial pressure (MAP) in all three groups, although these values remained higher in the oral dexmedetomidine group at all eight time points. Intravenous dexmedetomidine provided the best visualization of the surgical field for opening of the tympanic sinus, 30 min after the start of the infusion (p < 0.05). Intranasal dexmedetomidine provided a significantly better visual field than oral dexmedetomidine for the repair of a tympanic membrane perforation using the fascia temporal muscle (p < 0.05). Conclusion: A single low dose of dexmedetomidine administered intravenously or intranasally could decrease HR and MAP, improve surgical field visibility and be appropriate for deliberate hypotension for surgical procedures of 1-2 h in length. Trial registration: Clinicaltrials.gov identifier: NCT03800641.

Amnesia after Midazolam and Ketamine Sedation in Children: A Secondary Analysis of a Randomized Controlled Trial

The incidence of peri-procedural amnesia following procedural sedation in children is unclear and difficult to determine. This study aimed to apply quantitative and qualitative approaches to better understand amnesia following dental sedation of children. After Institutional Review Board Approval, children scheduled for sedation for dental procedures with oral midazolam (OM), oral midazolam and ketamine (OMK), or intranasal midazolam and ketamine (IMK) were recruited for examination of peri-procedural amnesia. Amnesia during the dental session was assessed using a three-stage method, using identification of pictures and an animal toy. On the day following the sedation, primary caregivers answered two questions about their children’s memory. One week later, the children received a semi-structured interview. Behavior and level of sedation during the dental session were recorded. Quantitative data were analyzed using descriptive statistics and comparison tests. Qualitative data were analyzed using content analysis. Triangulation was used. Thirty-five children (age: 36 to 76 months) participated in the quantitative analysis. Most children showed amnesia for the dental procedure (82.9%, n = 29/35) and remembered receiving the sedation (82.1%, n = 23/28 for oral administration; 59.3%, n = 16/27 for intranasal administration). The occurrence of amnesia for the dental procedure was slightly higher in the oral midazolam group compared with the other groups (44.8%, n = 13/29 for OM, 13.8%, n = 4/29 for OMK, and 41.4%, n = 12/29 for IMK). Twenty-eight children participated in the qualitative approach. The major theme identified was that some children could remember their procedures in detail. We conclude that peri-procedural amnesia of the dental procedure was common following sedation.

A Physiologically Based Pharmacokinetic Model for Predicting Diazepam Pharmacokinetics after Intravenous, Oral, Intranasal, and Rectal Applications

Diazepam is one of the most prescribed anxiolytic and anticonvulsant that is administered through intravenous (IV), oral, intramuscular, intranasal, and rectal routes. To facilitate the clinical use of diazepam, there is a need to develop formulations that are convenient to administer in ambulatory settings. The present study aimed to develop and evaluate a physiologically based pharmacokinetic (PBPK) model for diazepam that is capable of predicting its pharmacokinetics (PK) after IV, oral, intranasal, and rectal applications using a whole-body population-based PBPK simulator, Simcyp^®. The model evaluation was carried out using visual predictive checks, observed/predicted ratios (R_obs/pred), and the average fold error (AFE) of PK parameters. The Diazepam PBPK model successfully predicted diazepam PK in an adult population after doses were administered through IV, oral, intranasal, and rectal routes, as the R_obs/pred of all PK parameters were within a two-fold error range. The developed model can be used for the development and optimization of novel diazepam dosage forms, and it can be extended to simulate drug response in situations where no clinical data are available (healthy and disease).

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

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

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

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

Principles of Pharmacotherapy of Seizures and Status Epilepticus

Status epilepticus is a neurological emergency with an outcome that is highly associated with the initial pharmacotherapy management that must be administered in a timely fashion. Beyond first-line therapy of status epilepticus, treatment is not guided by robust evidence. Optimal pharmacotherapy selection for individual patients is essential in the management of seizures and status epilepticus with careful evaluation of pharmacokinetic and pharmacodynamic factors. With the addition of newer antiseizure agents to the market, understanding their role in the management of status epilepticus is critical. Etiology-guided therapy should be considered in certain patients with drug-induced seizures, alcohol withdrawal, or autoimmune encephalitis. Some patient populations warrant special consideration, such as pediatric, pregnant, elderly, and the critically ill. Seizure prophylaxis is indicated in select patients with acute neurological injury and should be limited to the acute postinjury period.

Randomized clinical trial on the efficacy of intranasal or oral ketamine-midazolam combinations compared to oral midazolam for outpatient pediatric sedation

Purpose

The optimal sedative regime that provides the greatest comfort and the lowest risk for procedural sedation in young children remains to be determined. The aim of this randomized, blinded, controlled, parallel-design trial was to evaluate the efficacy of intranasal ketamine and midazolam as the main component of the behavioral guidance approach for preschoolers during dental treatment.

Materials and methods

Children under seven years of age, with caries and non-cooperative behavior, were randomized into three groups: (KMIN) intranasal ketamine and midazolam; (KMO) oral ketamine and midazolam; or (MO) oral midazolam. The dental sedation appointments were videotaped, and the videos were analyzed using the Ohio State University Behavioral Rating Scale (OSUBRS) to determine the success of the sedation in each group. Intra- and postoperative adverse events were recorded. Data analysis involved descriptive statistics and non-parametric tests (P < 0.05, IBM SPSS).

Results

Participants were 84 children (28 per group; 43 boys), with a mean age of 3.1 years (SD 1.2). Children’s baseline and the dental sedation session characteristics were balanced among groups. The success of the treatment as assessed by the dichotomous variable ‘quiet behavior for at least 60% of the session length’ was: KMIN 50.0% (n = 14; OR 2.10, 95% CI 0.71 to 6.30), KMO 46.4% (n = 13; OR 1.80, 95% CI 0.62 to 5.40), MO 32.1% (n = 9) (P = 0.360). Adverse events were minor, occurred in 37 of 84 children (44.0%), and did not differ among groups (P = 0.462).

Conclusion

All three regimens provided moderate dental sedation with minor adverse events, with marked variability in the behavior of children during dental treatment. The potential benefit of the ketamine–midazolam combination should be further investigated in studies with larger samples.

Trial registration

ClinicalTrials.gov, identifier: NCT02447289. Registered on 11 May 2015, named “Midazolam and Ketamine Effect Administered Through the Nose for Sedation of Children for Dental Treatment (NASO).”

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.