How should midazolam nasal spray be administered, including appropriate dosing and technique?

Administration of Midazolam Nasal Spray

For intranasal midazolam administration, use a concentrated formulation (5 mg/0.1 mL or 50 mg/mL) delivered as a single spray into one nostril, with dosing of 0.2-0.3 mg/kg for children or 5 mg (0.1 mL) for adults, achieving peak plasma concentrations within 10-15 minutes.

Dosing by Age and Indication

Pediatric Dosing (Seizures)

• Standard dose: 0.2 mg/kg intranasally (maximum 6 mg per dose) 1
• May repeat every 10-15 minutes if seizures persist 1
• This IM dosing from guidelines can be extrapolated to intranasal use given similar bioavailability

Adult Dosing (General Sedation/Premedication)

• Standard bolus: 5 mg (0.1 mL of 50 mg/mL formulation) administered as one spray in one nostril 2, 3
• Can repeat after adequate time for assessment if needed
• Bioavailability is approximately 80-83% 2, 3, 4

Pediatric Premedication

• 0.2 mg/kg intranasally using 5 mg/mL concentration 5
• Onset occurs within 10 minutes (faster than rectal route which requires 20 minutes) 5
• Note: Oral administration (0.5 mg/kg) may be better tolerated emotionally than intranasal in younger children, though intranasal works faster 6

Administration Technique

Preparation

• Use concentrated formulation: 50 mg/mL (5 mg per 0.1 mL spray) 2, 3
• This high concentration minimizes volume and nasal irritation
• Lower concentrations require larger volumes and are less well-tolerated

Delivery Method

• Administer as single spray into one nostril 2
• Patient should be in upright or semi-recumbent position
• Avoid having patient blow nose immediately after administration
• The spray device delivers 0.1 mL per actuation

Pharmacokinetics and Onset

Time Course

• Onset of effect: 5-10 minutes 2, 3
• Peak plasma concentration: 10-15 minutes (mean 14 minutes) 3, 4
• Duration: 15-80 minutes depending on dose 7
• Plasma concentrations >30 ng/mL achieved within 5 minutes 2

Bioavailability

• Mean bioavailability: 82-83% 2, 3, 4
• This high bioavailability indicates minimal first-pass metabolism
• Formation of active metabolite (1-hydroxymidazolam) does not exceed IV administration, confirming predominantly nasal mucosal absorption rather than enteral 3, 4

Critical Safety Considerations

Respiratory Monitoring

• Continuous monitoring required regardless of route 8
• Pulse oximetry mandatory 9, 10
• Capnography strongly recommended, especially with supplemental oxygen 10
• Peak respiratory depression may occur 30 minutes after last dose 7

High-Risk Populations Requiring Dose Reduction

• Elderly (>60 years): Reduce dose by 20-50% 7, 11, 7
• ASA class III or higher: Reduce dose by at least 20% 7
• Concomitant opioids or CNS depressants: Reduce midazolam dose by 30-50% 1, 11, 8
• Hepatic or renal impairment: Clearance reduced, use lower doses 7

Rescue Capability Required

• Flumazenil must be immediately available 1
  • Dose: 0.2-0.4 mg IV every 2-3 minutes 11, 7
  • Caution: Reverses anticonvulsant effects and may precipitate seizures 1
• Age- and size-appropriate airway equipment mandatory 9, 8
• Personnel skilled in airway management must be present 9, 8

Common Pitfalls and Adverse Effects

Expected Side Effects

• Local nasal burning/irritation: Most common complaint, reported in 85% of patients 2, 3
• Generally well-tolerated despite discomfort 3
• Temporary and resolves within minutes

Serious Complications to Monitor

• Respiratory depression: Most serious risk, especially with co-administered opioids 1, 7, 11
• Paradoxical agitation: More common in younger children 1
• Oversedation: Allow 3-5 minutes between doses to assess peak effect 8

Contraindications

• Avoid in patients with severe nasal pathology or recent nasal surgery
• Do not use in neonates <32 weeks due to benzyl alcohol content 8
• Caution with concomitant CYP3A4 inhibitors (erythromycin, cimetidine) which increase bioavailability 7, 8

Practical Algorithm

For seizure management:

1. Administer 0.2 mg/kg IN (max 6 mg)
2. Wait 10-15 minutes
3. If seizure persists, repeat dose
4. If still inadequate, transition to IV benzodiazepine

For procedural sedation:

1. Ensure monitoring equipment in place
2. Administer 5 mg (adults) or 0.2 mg/kg (children) IN
3. Wait 10-15 minutes for peak effect
4. Assess sedation level before proceeding
5. Supplemental doses only after full assessment of initial dose effect

The intranasal route offers rapid absorption comparable to IM administration while avoiding the trauma of injection, making it particularly valuable in pediatric seizure management and when IV access is difficult or time-consuming to establish 12, 2, 3.