Midazolam Dosing for Febrile Convulsions

Route-Specific Dosing Algorithm

The American Academy of Pediatrics recommends administering intranasal midazolam 0.2 mg/kg (maximum 6 mg per dose) as the preferred first-line treatment when intravenous access is unavailable, or intravenous midazolam 0.1 mg/kg if IV access is established 1
For the intravenous route, the initial dose is 0.05-0.10 mg/kg administered slowly over 2-3 minutes (maximum single dose: 5 mg), with peak effect occurring at 3-5 minutes after administration, and may be repeated every 10-15 minutes if seizures persist 1, 2
The intramuscular route is an alternative, with a dose of 0.2 mg/kg (maximum 6 mg per dose), which may be repeated every 10-15 minutes if needed 1

For refractory seizures, a loading dose of 0.15-0.20 mg/kg IV is recommended, followed by a continuous infusion starting at 1 μg/kg/min (0.06 mg/kg/hr), which can be titrated by increments of 1 μg/kg/min every 15 minutes up to a maximum of 5 μg/kg/min (0.3 mg/kg/hr) until seizures stop 1, 2

There is an increased risk of apnea, especially when combined with other sedatives, and oxygen saturation should be monitored continuously, with preparation to provide respiratory support regardless of administration route 1, 2
Flumazenil should be available to reverse life-threatening respiratory depression, though this will also reverse anticonvulsant effects 1, 2

Lower doses of midazolam are ineffective for seizure control, and rapid IV administration should be avoided to prevent oversedation and hypotension 1, 2
Paradoxical agitation, especially in younger children, should be watched for, and treatment should not be delayed attempting IV access when the intranasal route is immediately available 1

The American College of Emergency Physicians recommends reducing all doses by 30-50% when combined with opioids or other CNS depressants 3
The American Academy of Pediatrics suggests that patients with hepatic impairment require dose reduction due to decreased clearance, although the exact reduction percentage is not specified 3

The American Heart Association advises that respiratory depression risk is highest when midazolam is combined with fentanyl or other opioids 3