Midazolam Dosing Frequency for Acute Seizures
Midazolam can be repeated every 5-10 minutes for ongoing seizures, with a maximum of 2-3 doses before escalating to alternative therapies or seeking emergency care. 1, 2
Initial Dosing by Route
Intravenous/Intraosseous Administration
- Pediatric patients (<6 months): Titrate with small increments starting at 0.05 mg/kg due to high risk of airway obstruction and hypoventilation 3
- Pediatric patients (6 months-5 years): 0.05-0.1 mg/kg initially, up to 0.6 mg/kg total (usually not exceeding 6 mg) 3
- Pediatric patients (6-12 years): 0.025-0.05 mg/kg initially, up to 0.4 mg/kg total (usually not exceeding 10 mg) 3
- Adolescents/Adults (≥12 years): Dose as adults, usually not exceeding 10 mg total 3
Intramuscular Administration
- Dose: 0.1-0.15 mg/kg (up to 0.2 mg/kg has been studied effectively) 4, 5, 6
- Onset: Seizure arrest typically occurs within 5-10 minutes 4
- Advantage: Rapidly absorbed due to water solubility, easier than IV access during active seizures 4
Nasal/Buccal Administration
- Buccal midazolam: Equally effective as rectal diazepam with 75% efficacy rate 7
- Timing: Monitor for 10 minutes after administration before considering additional doses 7
Repeat Dosing Protocol
Timing Between Doses
- IV/IO route: Repeat every 5 minutes as needed 1, 3
- IM route: If initial dose fails, can transition to IV administration rather than repeat IM 8
- Nasal/buccal route: If seizures continue after 10 minutes, administer second dose 2, 7
Maximum Dosing
- After 2 doses: If seizures persist, seek emergency medical care and consider alternative anticonvulsants 2
- Continuous infusion: For refractory seizures in intubated patients, loading dose of 0.05-0.2 mg/kg over 2-3 minutes, followed by continuous infusion 3
Critical Safety Considerations
Respiratory Monitoring
- Monitor oxygen saturation and respiratory status continuously, especially with repeat dosing 2, 7
- Higher doses (>0.4 mg/kg) carry increased risk of prolonged sedation and hypoventilation 3
- Each dose must be administered slowly over 2-3 minutes to allow full evaluation of sedative effect before repeating 3
Common Pitfall to Avoid
Do not repeat doses too quickly. Midazolam takes approximately 3 times longer than diazepam to achieve peak EEG effects, requiring a 2-3 minute wait between doses to fully evaluate the sedative effect 3. Premature repeat dosing significantly increases respiratory depression risk.
Transition to Long-Acting Anticonvulsants
- Midazolam should be followed immediately by a long-acting anticonvulsant such as phenytoin/fosphenytoin or oral carbamazepine, as benzodiazepines are rapidly redistributed and seizures often recur within 15-20 minutes 1, 8