What is the recommended dose of lorazepam (Ativan) intramuscularly (IM) for acute agitation?

Recommended Dose of Lorazepam IM for Acute Agitation

For acute agitation in adults, the recommended intramuscular (IM) dose of lorazepam is 2 mg, which can be repeated every 10-15 minutes as needed for continued agitation, with a maximum single dose of 4 mg. 1

Dosing Guidelines

Adult Dosing

• Initial dose: 2 mg IM
• Repeat dosing: May repeat every 10-15 minutes if needed
• Maximum single dose: 4 mg
• Route: Intramuscular injection

Special Populations

• Elderly patients: Consider starting with lower doses (0.5-1 mg) due to increased sensitivity to benzodiazepines
• Patients with hepatic impairment: Use lower doses as metabolism may be impaired

Clinical Considerations

Monitoring

• Monitor vital signs, particularly respiratory status
• Assess level of sedation after administration
• Be prepared to provide respiratory support as benzodiazepines can cause respiratory depression 1
• Monitor oxygen saturation continuously

Potential Adverse Effects

• Respiratory depression (increased risk when combined with other sedative agents)
• Paradoxical agitation (especially in younger patients)
• Hypotension
• Excessive sedation

Comparative Efficacy

While lorazepam is effective for acute agitation, evidence suggests that:

1. Droperidol may provide more rapid sedation than lorazepam when used as monotherapy 2
2. Combination therapy with an antipsychotic and benzodiazepine may be more effective than either agent alone 1
3. The combination of droperidol and midazolam has been shown to achieve adequate sedation faster than haloperidol and lorazepam 3

Alternative Approaches

For patients who can accept oral medications, consider:

• Oral combination of risperidone (2 mg) plus lorazepam (2 mg), which has been shown to be as effective as IM haloperidol plus lorazepam 4

Important Cautions

• Flumazenil may be administered to reverse life-threatening respiratory depression caused by lorazepam; however, it will also counteract the anticonvulsant effects and may precipitate seizures in patients with a seizure history 1
• There is an increased incidence of respiratory depression when lorazepam is combined with other sedative agents, particularly opioids
• Always have resuscitation equipment readily available when administering parenteral benzodiazepines

Clinical Decision Algorithm

1. Assess severity of agitation and need for immediate intervention
2. Attempt verbal de-escalation techniques first when possible
3. If pharmacological intervention is necessary:
   • For mild-moderate agitation: Consider oral options if patient is cooperative
   • For severe agitation requiring rapid control: Proceed with IM lorazepam 2 mg
4. Reassess after 10-15 minutes
5. If inadequate response, may administer a second dose of 2 mg IM
6. If still inadequate after two doses, consider alternative or adjunctive medication

Remember that while lorazepam is effective for acute agitation, the combination of a benzodiazepine with an antipsychotic may produce more rapid sedation in severely agitated patients 1.