What is the IV (intravenous) midazolam dose for seizure control as an infusion?

IV Midazolam Infusion Dosing for Seizure Control

For refractory status epilepticus, administer a loading dose of 0.15-0.20 mg/kg IV (7.5-10 mg for a 50 kg patient) followed by continuous infusion starting at 1 μg/kg/min (0.06 mg/kg/hr or approximately 3 mg/hr), titrating upward by 1 μg/kg/min every 15 minutes until seizures stop, with a maximum rate of 5 μg/kg/min (0.3 mg/kg/hr). 1, 2, 3

Initial Bolus Dosing

• Start with an IV bolus of 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 1, 2, 3
• This initial dose may be repeated every 10-15 minutes if seizures persist 1, 2, 3
• For patients who fail initial bolus therapy, escalate to the refractory protocol with loading dose and continuous infusion 1, 2, 3

Continuous Infusion Protocol for Refractory Seizures

Loading and Maintenance:

• Administer loading dose of 0.15-0.20 mg/kg IV (equivalent to 7.5-10 mg for a 50 kg adult) 1, 3
• Begin continuous infusion at 1 μg/kg/min (0.06 mg/kg/hr), which equals approximately 3 mg/hr for a 50 kg patient 1, 2, 3
• Research data supports starting at 1-5 μg/kg/min, with most patients achieving seizure control at a mean rate of 3.1 μg/kg/min 4

Titration Strategy:

• Increase infusion rate by 1 μg/kg/min every 15 minutes until seizures are controlled 2, 3
• Maximum infusion rate is 5 μg/kg/min (0.3 mg/kg/hr) 2, 3
• Clinical studies demonstrate seizure control typically occurs within 45-65 minutes at mean rates of 3-8 μg/kg/min 4, 5

Critical Dose Modifications

Reduce all doses by 30-50% when:

• Combined with opioids or other CNS depressants due to synergistic respiratory depression risk 2
• Concurrent opioid use requires at least 20% dose reduction 1

Reduce doses by at least 20% in:

• Hepatic or renal impairment due to decreased clearance 1, 3
• Elderly or frail patients (use 0.5-1 mg per dose maximum) 1

Safety Monitoring Requirements

Respiratory Precautions:

• Monitor oxygen saturation continuously throughout treatment 2, 3
• Respiratory depression can occur up to 30 minutes after administration 1
• Be prepared to provide immediate respiratory support regardless of route 2, 3
• Have flumazenil available for reversal, though this will also reverse anticonvulsant effects and may precipitate seizures 1, 2

Cardiovascular Monitoring:

• Watch for hypotension, especially with rapid IV administration 3
• Research data shows minimal cardiovascular effects when administered properly, with no significant changes in blood pressure or heart rate in controlled studies 4, 5

Common Pitfalls to Avoid

• Never use lower doses for seizure control - they are ineffective and delay definitive treatment 2
• Avoid rapid IV administration - give boluses slowly over 2-3 minutes to prevent oversedation and hypotension 2, 3
• Do not delay treatment attempting IV access when alternative routes (intranasal, intramuscular) are immediately available 2
• Watch for paradoxical agitation in younger children (6% incidence) 1, 2

Efficacy Data

Research demonstrates 94-96% seizure control rates with continuous midazolam infusion in refractory status epilepticus, with mean time to control of 45-65 minutes 4, 5. The response to treatment and mortality are primarily related to underlying etiology rather than the medication itself 4.