IV Benzodiazepines for Acute Anxiety
For acute anxiety in adults, administer diazepam 2-5 mg IV for moderate anxiety or 5-10 mg IV for severe anxiety, repeated every 3-4 hours as needed, with slow administration over 2-3 minutes to avoid pain and respiratory depression. 1
Recommended IV Benzodiazepines and Dosing
Diazepam (First-Line for Acute Anxiety)
- Moderate anxiety: 2-5 mg IV, repeat in 3-4 hours if necessary 1
- Severe anxiety: 5-10 mg IV, repeat in 3-4 hours if necessary 1
- Administer slowly over approximately 2 minutes to avoid pain at the IV site 2
- Long-acting benzodiazepine preferred for sustained anxiety levels 3
Lorazepam (Alternative Option)
- Adult dosing: 0.05-0.15 mg/kg IV (maximum single dose: 5 mg) 2
- May repeat hourly as necessary 2
- Slower onset but longer duration of action compared to diazepam 2
- Particularly effective for producing anterograde amnesia 4
Midazolam (For Sedation/Anxiolysis)
- Adult dosing: 0.05-0.10 mg/kg IV over 2-3 minutes (maximum single dose: 5 mg) 2
- Peak effect occurs at 3-5 minutes 2
- Dose/observe and redose/observe every 3-5 minutes to avoid oversedation 2
- Shorter-acting option for episodic anxiety 3
Administration Guidelines
Critical Safety Measures
- Monitor continuously: Oxygen saturation, respiratory rate, and blood pressure throughout administration 2
- Slow IV push: Administer over 2-3 minutes to minimize respiratory depression and pain at injection site 2
- Have reversal agent ready: Flumazenil should be immediately available for life-threatening respiratory depression 2
- Prepare for respiratory support: Be ready to provide ventilation assistance, as apnea risk increases significantly when combined with other sedative agents 2
Titration Strategy
- Start with the lower end of the dosing range 1
- Observe for 3-5 minutes after each dose before redosing 2
- Titrate to clinical effect (relief of anxiety symptoms, slurring of speech) rather than fixed dosing 1
- Avoid oversedation by using incremental dosing approach 2
Special Populations
Elderly Patients
- Reduce initial dose by 50%: Start with 0.05-0.1 mg/kg for lorazepam due to decreased drug metabolism 5
- Higher risk of respiratory depression and hypotension 5
- Monitor for paradoxical agitation, which can occur in elderly patients 5
- Prolonged monitoring essential due to extended drug effects 5
Patients with Organ Dysfunction
- Adjust dosing for hepatic or renal impairment 5
- Consider midazolam over diazepam, as it is less dependent on specific organ metabolism 6
Common Pitfalls and Caveats
Respiratory Depression Risk
- Highest risk: When combining benzodiazepines with opioids or other sedatives 2
- Rapid IV administration increases apnea risk 2
- Elderly patients and those with chronic lung disease require extreme caution 1
Paradoxical Reactions
- Agitation or excitement may occur, especially in younger children and elderly patients 2, 5
- If paradoxical reaction occurs, discontinue benzodiazepine and consider alternative sedation 2
Hypotension
- May occur with rapid administration or in hemodynamically unstable patients 2, 5
- Monitor blood pressure continuously during administration 5
Drug Interactions
- Benzodiazepines potentiate effects of other CNS depressants 2
- Elderly patients on multiple medications at highest risk for interactions 5
Flumazenil Considerations
- Reverses respiratory depression but also reverses anxiolytic effects 2
- Contraindicated in tricyclic antidepressant overdose (may induce seizures) 2
- Use with extreme caution in patients with seizure disorders 2
- Duration of action shorter than most benzodiazepines; re-sedation may occur 2