Onset of Action for Intramuscular Lorazepam

Pharmacokinetic Profile

Intramuscular lorazepam begins to work within 15-20 minutes after injection, with peak effects occurring at approximately 60-90 minutes, according to the American Academy of Pediatrics 1
The onset of action for intramuscular lorazepam is 15-20 minutes after injection, with a peak effect at approximately 60 minutes after administration, as recommended by the American Academy of Pediatrics 1
The duration of effect for intramuscular lorazepam is 6-8 hours, as stated by the American Academy of Pediatrics 1
Oral lorazepam has a longer onset time of 20-30 minutes and peaks at approximately 2 hours after administration, as reported by the American Gastroenterological Association 2

For acute agitation management in adults, a typical intramuscular dosing is 2 mg, which may be repeated every 30-60 minutes as needed, according to the American Academy of Pediatrics 1
For acute agitation management in adolescents, a typical intramuscular dosing is 0.05-0.1 mg/kg, as recommended by the American Academy of Pediatrics 1
Intramuscular lorazepam has a relatively rapid onset, making it suitable for acute behavioral emergencies, although it is slower than intravenous administration, as stated by the American Gastroenterological Association 2

The major adverse effect of intramuscular lorazepam is dose-dependent respiratory depression, particularly when combined with opioids or in patients with underlying respiratory disease, as reported by the American Gastroenterological Association 2 and 3
Close monitoring is essential after administration of intramuscular lorazepam due to the risk of respiratory depression, as recommended by the American Gastroenterological Association 3
Patients require extended monitoring, even after apparent recovery, due to the elimination half-life of approximately 12 hours, as stated by the American Gastroenterological Association 3
Younger patients and those with developmental disabilities may experience behavioral disinhibition rather than sedation when administered intramuscular lorazepam, as reported by the American Academy of Pediatrics 1