What are the recommended PRN (as needed) medications for anxiety management?

PRN Medications for Anxiety Management

Lorazepam (1 mg) and midazolam (2.5 mg) are the recommended first-line PRN medications for acute anxiety management, with quetiapine (25 mg) as an effective non-benzodiazepine alternative. 1

Benzodiazepine Options

First-Line Benzodiazepines

• Lorazepam:

  • Dosing: 1 mg subcutaneous or intravenous (up to 2 mg maximum) 2, 1
  • Can also be given orally or sublingually 2
  • Advantages: Intermediate duration of action, reducing risk of interdose anxiety
  • Cautions: May cause drowsiness, paradoxical agitation, and increased fall risk 2

• Midazolam:

  • Dosing: 2.5 mg subcutaneous or intravenous every hour PRN (up to 5 mg maximum) 2, 1
  • Advantages: Rapid onset of action for acute anxiety
  • Cautions: May cause delirium, drowsiness, dizziness, and paradoxical agitation 2

Important Considerations for Benzodiazepines

• Use lower doses in older or frail patients, those with COPD, or when co-administered with antipsychotics 2
• Benzodiazepines are the treatment of choice for alcohol or benzodiazepine withdrawal 2
• Contraindicated in patients with severe pulmonary insufficiency, severe liver disease, or myasthenia gravis (unless in imminently dying patients) 2
• Increased risk of falls, particularly in elderly patients 2, 1

Non-Benzodiazepine Options

Antipsychotics

• Quetiapine:

  • Dosing: 25 mg orally 1
  • Advantages: Less risk of dependence than benzodiazepines, indicated for anxiety with delirium
  • Cautions: May cause sedation and orthostatic hypotension 1

• Olanzapine:

  • Dosing: 2.5-5 mg orally daily 1
  • Available as an orally disintegrating tablet for rapid absorption
  • Caution: Should not be combined with benzodiazepines due to risk of oversedation and respiratory depression 1

• Aripiprazole:

  • Dosing: 5 mg orally or intramuscular (immediate-release) 2
  • Less likely to cause extrapyramidal side effects
  • May cause headache, agitation, anxiety, insomnia, dizziness, drowsiness 2

Monitoring Requirements

• Monitor for orthostatic hypotension with any antipsychotic medication 1
• Avoid antipsychotics in patients at risk for torsades de pointes (baseline QT prolongation) 1
• Reduce doses in older patients and those with severe renal or hepatic impairment 2

Special Populations

Elderly Patients

• Start with lower doses than those used in younger adults 1
• Titrate doses slowly to minimize side effects 1
• Quetiapine is recommended as the first-line antipsychotic for managing delirium in elderly patients due to reduced duration of delirium and lower risk of extrapyramidal side effects 1

Patients with Comorbidities

• Avoid haloperidol in patients with Parkinson's disease or Lewy body dementia 1
• Use caution with benzodiazepines in patients with respiratory conditions 2, 1
• Consider drug interactions, particularly with cytochrome P450 2D6 and 3A4 inhibitors 2

Common Pitfalls to Avoid

• Using excessive doses in elderly patients 1
• Not monitoring for QTc prolongation with certain antipsychotics 1
• Overlooking the potential for all antipsychotics to cause sedation 1
• Failing to reduce doses appropriately in elderly or medically compromised patients 1
• Switching too quickly between antipsychotics without proper cross-titration 1

Long-term Considerations

• For chronic anxiety disorders, SSRIs and SNRIs are first-line pharmacotherapy rather than PRN medications 3
• Benzodiazepines are not recommended for long-term use due to risks of cognitive disorders, dependence, and withdrawal syndromes 4
• When anxiety requires longer-term treatment, the need for continued medication should be periodically reassessed 5