Intramuscular Benzodiazepines: Use Midazolam

When you don’t have an IV, use midazolam for seizures and agitation. The dose is 0.2 mg/kg IM.

midaz-vs-diaz-IM-route.pdf-page-4-of-6.jpg (JPEG Image, 698x720 pixels)

“…The time to maximum plasma concentrations (Cmax) was shorter for midazolam (17.5 ± 6.5 min) than for diazepam (33.8 ±7.5 min). (P < 0.05, Table II) The IM absorption profiles for midazolam and diazepam demonstrate that there is more variability in the absorption rates of IM diazepam than those of IM midazolam (Figure 2). The mean time to peak absorption rate was shorter for midazolam (9 ±2 min) than for diazepam (13.8 ±7.5 min). The absorption of midazolam was almost complete within one hour following the im administration. However, for diazepam, considerable drug absorption continued, with larger variability, beyond one hour after the IM injection.”

Hung, Dyck, Varvel et al. Comparative absorption kinetics of intramuscular midazolam and diazepam. Can J Anaesth 1996;43:5 pp 450-5.

“Midazolam is the only benzodiazepine stable in aqueous solution and suitable for intramuscular injection. A delayed onset of action might be expected, as shown by Jawad et al., but this was not confirmed by Chamberlain et al. Intramuscular midazolam may be useful in patients when attempts to introduce an intravenous line are unsuccessful. It appeared to be well tolerated and rapidly effective for treatment of acute seizures.”

Wermeling, Archer, Manaligod et al. Bioavailability and pharmacokinetics of lorazepam after intranasal, intravenous, and intramuscular administration. J Clin Pharmacol 2001;41:1225-1231.

M vs L vs H for agitation.pdf (page 4 of 6)

“We found that midazolam is superior to haloperidol and lorazepam in the sedation of violent and severely agitated patients (VSAPs) with respect to time to sedation and time to arousal. The use of midazolam in the control of VSAPs can facilitate patient care, rapidly ease the disruption to the ED, and hasten disposition.”

Nobay, Simon, Levitt et al. A Prospective, Double-blind, Randomized Trial of Midazolam versus Haloperidol versus Lorazepam in the Chemical Restraint of Violent and Severely Agitated Patients. Acad Emerg Med 2004;11:744-749.

Thanks to Sara Bingel.

also note



RASS Richmond Agitation Sedation Scale