Recommended Dosing of IV Midazolam for Procedural Sedation
The recommended initial intravenous dose of midazolam for procedural sedation in healthy adults younger than 60 years is 1 mg (or no more than 0.03 mg/kg) injected over 1-2 minutes, with additional doses of 1 mg (or 0.02-0.03 mg/kg) administered at 2-minute intervals until adequate sedation is achieved. 1
Adult Dosing Algorithm
- Initial dose for healthy adults <60 years: 1 mg IV (or no more than 0.03 mg/kg) administered over 1-2 minutes 1
- Wait 2 minutes to evaluate sedative effect 1
- Additional doses: 1 mg (or 0.02-0.03 mg/kg) at 2-minute intervals until adequate sedation is achieved 1
- Maximum total dose: Usually not more than 6 mg for routine procedures 1
Special Population Considerations
Elderly Patients (≥60 years) and High-Risk Patients
- Reduce initial dose by at least 20% 1
- Initial dose: No more than 1.5 mg administered over at least 2 minutes 2
- Wait at least 2 minutes to evaluate effect before additional dosing 2
- Maximum total dose: Usually not more than 3.5 mg 2
Patients with Hepatic or Renal Impairment
- Reduce dose due to decreased midazolam clearance 1, 3
- Titrate more carefully with smaller increments 3
Pediatric Dosing
- Ages 6 months to 5 years: 0.05-0.1 mg/kg initially; total dose up to 0.6 mg/kg (not exceeding 6 mg) 2
- Ages 6-12 years: 0.025-0.05 mg/kg initially; total dose up to 0.4 mg/kg (not exceeding 10 mg) 2
- Ages 12-16 years: Dose as adults (not exceeding 10 mg total) 2
Important Safety Considerations
- Major side effect is respiratory depression - deaths have been reported when combined with opioids 1
- When midazolam is used with an opioid, a synergistic interaction occurs requiring dose reduction 1, 3
- Rapid administration is associated with increased risk of apnea 1
- Immediate availability of resuscitation equipment and personnel trained in airway management is essential 2
- Monitor oxygen saturation continuously during and after the procedure 3, 4
Common Pitfalls and Caveats
- Apnea may occur as long as 30 minutes after the last dose of midazolam 1
- Overall complication rate of approximately 1% has been reported in emergency department settings 4
- Respiratory depression risk increases significantly when combined with opioids 4, 5
- Flumazenil can be used to reverse life-threatening respiratory depression but will also reverse sedative effects 3
- Patients should be monitored for an extended period after sedation 1
Effectiveness and Onset
- Onset of effect: 1-2 minutes after IV administration 1
- Peak effect: 3-4 minutes after administration 1
- Duration of effect: 15-80 minutes 1
- Midazolam is 1.5-3.5 times more potent than diazepam 1
By following these dosing guidelines and monitoring protocols, midazolam can be safely and effectively used for procedural sedation while minimizing the risk of adverse events.