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).

Systematic review and meta-analysis found that intranasal dexmedetomidine was a safe and effective sedative drug during paediatric procedural sedation

AIM

This systematic review and meta-analysis evaluated the effectiveness of intranasal dexmedetomidine as a sole sedative during paediatric procedural sedation outside the operating room.

METHODS

Relevant literature identified by PubMed, Scopus, ClinicalTrials.gov, ScienceDirect and Cochrane Library up to 31 December 2019 was systematically reviewed. Randomised controlled trials that compared intranasal dexmedetomidine with another sedative or placebo during paediatric procedural sedation were included. Trials that studied intranasal dexmedetomidine as a premedication before anaesthesia were excluded. The primary outcome was the success of the planned procedure.

RESULTS

We analysed seven randomised controlled trials of 730 patients: four trials with 570 patients compared dexmedetomidine with chloral hydrate and three trials with 160 patients compared dexmedetomidine with midazolam. The incidence of successfully completing the procedure did not differ between dexmedetomidine and chloral hydrate, but dexmedetomidine had a higher success rate than midazolam. The incidence of hypotension, bradycardia or respiratory complications did not differ between the sedatives used. Nausea and vomiting were more common in children treated with chloral hydrate than in those treated with other sedatives.

CONCLUSION

Intranasal dexmedetomidine was a safe and effective sedative for minor paediatric procedures.

To Evaluate the Efficiency of Dexmedetomidine in Atomized Intranasal form for Sedation in Minor Oral Surgical Procedures

Aim

This study aims to evaluate the efficiency of dexmedetomidine in atomized intranasal form for sedation in minor oral surgical procedures.

Materials and Methods

A total 25 patients fitting the inclusion and exclusion criteria were selected from the outpatient Department of Oral and Maxillofacial Surgery, Saraswati Dental College and Hospital, Lucknow. The drug was administered intranasally half an hour before the surgical procedure. The volume of drug used was recorded. The readings of all the parameters of sedation began 30 min after the drug had been administered. Intranasal sedation status was assessed by Ramsay sedation score and observer's assessment of alertness/sedation scales, every 15 min throughout the procedure.

Results

The primary outcome variable in this study is depth of sedation produced by intranasally administered dexmedetomidine. Secondary variables included respiratory rate, blood pressure (BP), heart rate (HR), and oxygen saturation (SpO₂). The statistical software used was SPSS 20.0 for Windows (SPSS, Chicago, IL, USA). Data were expressed as mean and standard deviation or number (percentages). Sedation and behavior scores were analyzed by proportions. Hemodynamic variables including HR, SpO₂, and BP and respiratory rate were analyzed by repeated measures ANOVA. When a significant result was obtained, the Tukey test was applied for post hoc pairwise comparisons. P < 0.05 was considered as statistically significant. All the parameters were recorded at a set interval of time.

Conclusion

In conclusion, intranasal administration of 1.5 mg/kg atomized dexmedetomidine was clinically effective, convenient, and safe for the sedation of patients undergoing minor oral surgical procedures.