Midazolam Dosing for Adult Sedation
The recommended initial intravenous dose of midazolam for sedation in healthy adults younger than 60 years is 1 mg (or 0.03 mg/kg) administered over 1-2 minutes, with additional 1 mg doses given at 2-minute intervals until adequate sedation is achieved. 1
Standard Dosing Guidelines
Healthy Adults Under 60 Years
- Initial dose: 1 mg IV (or 0.03 mg/kg) administered over 1-2 minutes
- Wait 2+ minutes to evaluate sedative effect
- Additional doses: 1 mg (0.02-0.03 mg/kg) at 2-minute intervals until desired sedation
- Maximum total dose: 6 mg is typically sufficient for routine procedures 1
- When combined with opioids: Reduce midazolam dose due to synergistic effects
Adults 60+ Years or Debilitated Patients
- Initial dose: 1 mg IV (or less than 0.03 mg/kg) administered over 1-2 minutes
- Wait 2+ minutes to evaluate sedative effect
- Additional doses: No more than 1.5 mg over 2 minutes, waiting 2+ minutes between doses
- Dose reduction: At least 20% compared to younger adults 1, 2
- Maximum total dose: 3.5 mg is typically sufficient 2
- When combined with opioids: Reduce dose by at least 50% compared to unpremedicated patients 2
Pharmacokinetic Profile
- Onset of action: 1-2 minutes after IV administration
- Peak effect: 3-4 minutes
- Duration of effect: 15-80 minutes 1
- Midazolam is 1.5-3.5 times more potent than diazepam 1
Special Considerations
Factors Requiring Dose Reduction
- Age >60 years
- ASA physical status III or greater
- Hepatic or renal impairment
- Obesity
- Concomitant use of opioids or other CNS depressants
- Use of H2-receptor antagonists (increases bioavailability by ~30%) 1
Safety Precautions
- Administer slowly (over 1-2 minutes) to reduce risk of respiratory depression 2
- Monitor respiratory status, oxygen saturation, and vital signs
- Have flumazenil available for reversal of benzodiazepine effects 3
- Ensure immediate availability of resuscitative drugs and equipment 2
- For deeply sedated patients, a dedicated individual should monitor the patient throughout the procedure 2
Maintenance Dosing
- Additional doses may be given at 25% of the initial effective dose to maintain sedation
- Administer maintenance doses only after thorough clinical evaluation confirms need for additional sedation 2
Adverse Effects
- Primary concern: Respiratory depression (may occur up to 30 minutes after administration) 1
- Risk increases with rapid administration and when combined with opioids 1
- Other potential effects: Cardiac dysrhythmias (rare), disinhibition reactions 1
Midazolam offers advantages over diazepam including more rapid onset, shorter duration, superior amnestic properties, and fewer adverse events including less thrombophlebitis 1. When properly dosed and monitored, midazolam provides effective procedural sedation with a favorable safety profile.