Midazolam

1. See Also
   1. Benzodiazepine
   2. Procedural Sedation and Analgesia (PSAA)
   3. Rapid Sequence Intubation
2. Indications
   1. Procedural Sedation and Analgesia (PSAA)
   2. Rapid Sequence Intubation (induction agent)
      1. Other induction agents are preferred due to the large and unpredictable Midazolam doses required for induction
      2. Consider where IV Access unavailable or other intubation agents contraindicated
3. Class
   1. Parenteral short acting Benzodiazepine
4. Mechanism
   1. Sedative, Anxiolytic, and amnestic effects
   2. Antagonist: Flumazenil
5. Dosing: Procedural Sedation
   1. Intravenous
      1. Age 6 months to 5 years
         1. Initial: 0.05 to 0.1 mg/kg IV
         2. Titrate: Up to 1 mg increments IV every 3 min to max of 0.6 mg/kg
      2. Age 6 to 12 years
         1. Initial: 0.025 to 0.05 mg/kg IV
         2. Titrate: Up to 1 mg increments IV every 3 min to max of 0.4 mg/kg
      3. Adults (and over age 12 years)
         1. Initial: 0.02 mg/kg IV
         2. Titrate: 1 mg increments IV every 3 min (typically up to 5 mg)
   2. Intramuscular
      1. Child: 0.1 to 0.15 mg/kg (up to 10 mg)
      2. Adult: 0.07 mg/kg (up to 10 mg)
   3. Oral: 0.5 mg/kg/dose
   4. Nasal: 0.2 to 0.5 mg/kg intranasal (1/2 in each nostril) using 5 mg/ml up to 10 mg
   5. Rectal 0.25 to 0.5 mg/kg/dose per rectum
   6. Commonly used in combination with Fentanyl
      1. When combined with Opioids (e.g. Fentanyl), use lower Midazolam dose
   7. Reversal: Flumazenil
6. Pharmacokinetics
   1. General
      1. Duration: 1-4 hours
      2. Half life: 2.5 hours
   2. Oral
      1. Onset: 20 to 30 minutes
      2. Peak: 40 minutes
   3. Intramuscular
      1. Onset: 5 to 7 minutes (up to 10-20 minutes)
      2. Peak: 10 to 15 minutes
      3. Duration: 60-120 minutes
   4. Intravenous
      1. Onset: 2-3 minutes
      2. Peak: 5 to 10 minutes
      3. Duration: 45-60 minutes
7. Precautions
   1. Monitor closely with respiratory depression
   2. Have Ambubag and Oxygen available when administered
   3. Unpredictable at increased doses (risk of respiratory and cardiovascular depression)
      1. Best delivered in incremental doses (e.g. 1 mg increments)
   4. Use with caution if risks for respiratory depression
      1. Elderly, debilitated patients or children
      2. Concurrent Narcotic use
      3. Existing CNS depression
      4. Chronic lung disease
      5. Neuromuscular disorder
      6. Apnea history
8. References
   1. Miner (2012) APLS Lecture, HCMC, Minneapolis
   2. Hamilton (2012) Tarascon Pharmacopeia, Jones and Bartlett, Burlington
   3. Rispoli (2002) Tarascon Pocket Orthopedics, Loma Linda, p. 115
   4. University Minnesota Childrens - Pediatric Emergency Drug Card
   5. Becker (2012) Anesth Prog 59:28-42
   6. Brown (2005) Am Fam Physician 71:85-90
   7. Singh in Blaivas (2012) Emergency Medicine - an International Perspective, p. 199-208