What intranasal benzodiazepine nasal spray is recommended for acute seizure rescue and what are the dosing guidelines for adults and children?

Intranasal Midazolam is the Recommended Benzodiazepine Nasal Spray for Acute Seizure Rescue

Midazolam nasal spray (MDZ-NS) is FDA-approved and recommended for acute treatment of seizure clusters and prolonged seizures in patients 12 years and older with epilepsy, with a standard dose of 5 mg administered intranasally. 1

Dosing Guidelines

Adults

• Standard dose: 5 mg intranasal midazolam 2
• May repeat every 10-15 minutes if seizures continue 3
• Maximum single dose: 6 mg per administration 3

Children

• Weight-based dosing: 0.2 mg/kg intranasally 3
• Maximum: 6 mg per dose 3
• May repeat every 10-15 minutes as needed 3

Clinical Context and Rationale

The intranasal route provides several advantages over traditional routes when IV access is unavailable. Midazolam nasal spray achieves therapeutic plasma concentrations with a median time to maximum concentration (Tmax) of 45 minutes, and can be administered during active convulsive seizures or in the postictal period with comparable pharmacokinetics 4. This is particularly valuable since the 2008 AAP guidelines note that "other benzodiazepines (eg, lorazepam) are typically used for initial IV treatment of status epilepticus" but midazolam IM at 0.2 mg/kg provides an alternative when IV access is not available 3.

Evidence for Effectiveness

In clinical trials, 54.8% of patients treated with midazolam nasal spray 5 mg were seizure-free for 6 hours following treatment, compared to 38.7% with placebo 2. More impressively, in real-world use for seizure clusters, a single dose terminated 87.4% of seizure clusters within 24 hours 5. For tonic-clonic status epilepticus specifically, 61.7% of episodes terminated by 30 minutes after seizure onset, and 49.8% terminated within 20 minutes of dose administration 6.

Dual Utility: ACT and REST

Midazolam nasal spray serves two critical functions based on recent expert consensus:

• Acute Cluster Treatment (ACT): Prevents progression of seizure clusters - only 13% of treated clusters required a second dose within 24 hours 5
• Rapid and Early Seizure Termination (REST): Stops prolonged seizures - 67.3% of clusters were treated within 5 minutes of onset 5

Alternative: Diazepam Nasal Spray

While midazolam is the primary FDA-approved intranasal benzodiazepine, diazepam nasal spray is also available and effective, particularly for tonic-clonic status epilepticus. Diazepam nasal spray at approximately 0.2 mg/kg demonstrated that 65% of patients remained seizure-free during the 12-hour observation period 4. Recent data shows it terminated tonic-clonic status epilepticus in 61.7% of cases by 30 minutes 6.

Critical Safety Considerations

Respiratory Depression Risk

There is an increased incidence of apnea when benzodiazepines are combined with other sedative agents 3. Be prepared to provide respiratory support regardless of route of administration. Monitor oxygen saturation continuously.

Important Caveats

• Flumazenil should NOT be routinely used to reverse benzodiazepine effects in seizure patients, as it will reverse anticonvulsant effects and may precipitate recurrence of seizures 3
• Paradoxical agitation may occur, especially in younger children 3
• Nasopharyngeal irritation is typically mild and resolves by 12 hours post-dose 4

When IV Access IS Available

If IV access is available, the WHO guidelines recommend IV lorazepam is preferred over diazepam 7. The 2008 AAP guidelines specify lorazepam 0.05-0.10 mg/kg IV (maximum 4 mg per dose), which may be repeated every 10-15 minutes 3.

Clinical Algorithm

1. No IV access + active seizure or seizure cluster: Administer midazolam nasal spray 5 mg (adults) or 0.2 mg/kg (children, max 6 mg)
2. Monitor respiratory status - have oxygen and bag-valve-mask ready
3. If seizure continues after 10-15 minutes: May repeat dose once
4. If seizures persist after second intranasal dose: Establish IV access and proceed to second-line agents (levetiracetam, fosphenytoin, or valproic acid per 2024 ACEP guidelines) 8
5. Do NOT use flumazenil unless life-threatening respiratory depression occurs AND seizures have terminated

The intranasal route represents a significant advance in out-of-hospital seizure management, allowing non-medical personnel to administer effective treatment quickly, potentially preventing progression to status epilepticus and reducing emergency department visits 1, 9.