Can Ativan (Lorazepam) Be Given Intramuscularly?
Yes, Ativan (lorazepam) can be administered intramuscularly and is explicitly approved by the FDA for IM use, though it is not the preferred route for status epilepticus when IV access is available. 1
FDA-Approved IM Administration
- Lorazepam IM is FDA-approved for preanesthetic use at a dose of 0.05 mg/kg up to a maximum of 4 mg, administered at least 2 hours before the anticipated procedure for optimum effect. 1
- For status epilepticus, IM lorazepam is not preferred because therapeutic levels are not reached as quickly as with IV administration; however, when an intravenous port is unavailable, the IM route may prove useful. 1
- Equipment to maintain a patent airway must be immediately available prior to administration regardless of route. 1
Clinical Practice Guidelines Support IM Use
- The American Academy of Pediatrics recommends IM lorazepam at 0.2 mg/kg (maximum 6 mg per dose) for seizure management when IV access is unavailable, which can be repeated every 10-15 minutes. 2
- Lorazepam is strongly preferred over diazepam for IM administration because it has fast onset, rapid and complete absorption, and no active metabolites, whereas diazepam has erratic absorption when given IM and should NOT be used via this route. 2
- ESMO guidelines for delirium management list lorazepam 1 mg subcutaneous or IV as an option (noting it can also be given IM), though lower doses (0.25-0.5 mg) should be used in older or frail patients or those with COPD. 3
Key Advantages Over Diazepam IM
- Lorazepam has superior IM absorption compared to diazepam, which has erratic and unreliable absorption and carries a risk of tissue necrosis when given intramuscularly. 4, 2
- Historical pharmacokinetic data confirms that lorazepam is better absorbed after IM administration than diazepam, making it the benzodiazepine of choice for this route. 5
Critical Safety Considerations
- Respiratory depression is a significant risk, particularly when combined with other sedatives, antipsychotics, or opioids—continuous monitoring of oxygen saturation is mandatory. 2
- Common adverse effects include delirium, drowsiness, paradoxical agitation, and subcutaneous injection may cause local irritation. 3
- Dose reduction is essential in elderly or frail patients and those with COPD, especially when co-administered with antipsychotics (use 0.25-0.5 mg instead of standard doses). 3
- Increased risk of falls necessitates careful patient monitoring and environmental safety measures. 3
Clinical Context for IM Use
- IM lorazepam combined with an antipsychotic is frequently recommended by experts for managing acute agitation in children and adolescents. 2
- For acute agitation in adults, IM lorazepam may have a role as crisis medication in managing delirious patients with severe agitation and distress. 3
- The IM route is particularly valuable when oral administration is refused or impractical and IV access cannot be rapidly established. 1