What is an appropriate as-needed medication for a patient with anxiety, considering their medical history and potential for substance abuse?

As-Needed Medication for Anxiety

For as-needed anxiety management, lorazepam 0.5-1 mg orally is the preferred benzodiazepine when acute pharmacological intervention is absolutely necessary, though benzodiazepines should be avoided whenever possible due to significant risks of cognitive impairment, falls, dependence, and respiratory depression—especially in elderly patients and those on opioids. 1, 2

Critical Safety Considerations Before Prescribing

Absolute Contraindications and High-Risk Scenarios

• Never prescribe benzodiazepines concurrently with opioids due to fatal respiratory depression risk, as emphasized by the 2019 AGS Beers Criteria 1, 3
• Avoid benzodiazepines entirely in elderly patients (age >65) due to increased risk of cognitive impairment, delirium, falls, fractures, and enhanced sensitivity even at low doses 1
• Screen for substance abuse history before any benzodiazepine prescription, as these medications carry significant dependence and addiction potential 1

When Benzodiazepines Might Be Considered

Benzodiazepines as-needed are only appropriate for:

• Acute stress reactions requiring immediate symptom relief 4
• Episodic anxiety with discrete, predictable triggers 4
• Very short-term use (ideally 1-7 days maximum, rarely up to 2-4 weeks) 4
• Patients already on chronic benzodiazepines with breakthrough symptoms 2

Preferred As-Needed Benzodiazepine: Lorazepam

Dosing Algorithm

• Standard adult dose: 0.5-1 mg orally, up to four times daily as needed 2
• Elderly or debilitated patients: Reduce to 0.25-0.5 mg, with maximum 2 mg in 24 hours 1, 2
• Rationale for lorazepam: Intermediate duration of action, predictable pharmacokinetics without active metabolites, and ability to dose as-needed make it superior to alprazolam or diazepam for PRN use 2, 5

Why Not Other Benzodiazepines?

• Alprazolam: Not recommended, especially for long-term use, due to higher dependence risk and shorter half-life causing rebound anxiety 4
• Diazepam: Long-acting formulation better suited for sustained anxiety rather than episodic PRN use 5
• Short-acting potent agents (triazolam): Carry greater risks of adverse effects 4

Superior Alternative: Address Underlying Anxiety Disorder

First-Line Chronic Treatment (Not PRN)

The fundamental problem with "as-needed" anxiety medication is that anxiety disorders require scheduled, daily treatment—not PRN management. 6, 7

• SSRIs (sertraline or escitalopram) are first-line pharmacotherapy for generalized anxiety disorder, social anxiety disorder, and panic disorder 1, 7

  • Sertraline: Start 25 mg daily in elderly, 50 mg in younger adults 1
  • Escitalopram: Preferred due to least CYP450 interactions 1
  • Effect size vs placebo: SMD -0.55 to -0.67 (medium to large effect) 7

• Cognitive Behavioral Therapy (CBT) has the highest level of evidence for anxiety disorders with effect sizes of Hedges g = 0.39 to 1.01 1, 6, 7

Buspirone as PRN Alternative (Limited Utility)

• Buspirone 5 mg twice daily (maximum 20 mg three times daily) can be considered for mild-to-moderate anxiety 1
• Major limitation: Takes 2-4 weeks to become effective, making it unsuitable for true "as-needed" use 1
• Best for: Relatively healthy patients without substance abuse history who need non-benzodiazepine option 1

Clinical Algorithm for As-Needed Anxiety Requests

Step 1: Determine if PRN Treatment is Appropriate

• Is this episodic, predictable anxiety with discrete triggers? → Consider short-term lorazepam 4
• Is this chronic, sustained anxiety present most days? → Initiate scheduled SSRI, not PRN medication 6, 7
• Is this panic disorder? → Scheduled SSRI/SNRI is indicated, not PRN benzodiazepines 8, 7

Step 2: Risk Stratification

• Check for concurrent opioid use → Absolutely avoid benzodiazepines 3, 1
• Age >65 years → Avoid benzodiazepines; consider buspirone or scheduled SSRI 1
• Substance abuse history → Avoid benzodiazepines; use buspirone or SSRIs 1
• Multiple medications/polypharmacy → Choose escitalopram (fewest drug interactions) over benzodiazepines 1

Step 3: If Benzodiazepine Prescribed

• Limit prescription to 7-14 days maximum 4
• Provide explicit instructions: "Use only for severe anxiety episodes, not daily" 5
• Schedule follow-up in 1-2 weeks to transition to scheduled SSRI/SNRI 6
• Counsel on risks: Cognitive impairment, falls (especially elderly), dependence, withdrawal 1

Common Pitfalls to Avoid

• Never refill benzodiazepines indefinitely as PRN: This creates dependence without addressing underlying disorder 4
• Don't abruptly discontinue benzodiazepines: Taper gradually over 10-14 days minimum to avoid withdrawal syndrome (anxiety, seizures, delirium tremens) 3, 1
• Don't use benzodiazepines as monotherapy for anxiety disorders: They should only bridge to definitive treatment with SSRIs/SNRIs and CBT 6, 7
• Don't prescribe alprazolam for PRN use: Its short half-life and high potency increase dependence risk 4

When Benzodiazepines Fail or Are Contraindicated

Augmentation Strategy for Severe Anxiety

• Add low-dose haloperidol 0.5-1 mg orally at night and every 2 hours when required for severe, persistent anxiety unresponsive to other measures 2
• Consider aripiprazole 5-10 mg daily if patient has comorbid conditions 2

Non-Pharmacological Interventions

• Address reversible causes: Medical conditions (hyperthyroidism, cardiac arrhythmias), caffeine intake, medication side effects 1
• Effective communication: Explore specific concerns and anxieties, ensure orientation and support 1
• Immediate CBT referral: Individual therapy preferred over group therapy for superior clinical effectiveness 1