What is the best course of action for an elderly patient with a history of anxiety, previously treated with duloxetine, who was switched to Lexapro (escitalopram) 10mg but has not shown an adequate response?

Increasing Escitalopram and Adding Buspirone for Elderly Anxiety

Yes, increase escitalopram to 20 mg daily (not 15 mg) and add buspirone 5 mg twice daily, titrating to 15-20 mg three times daily over 2-4 weeks, but only after confirming the patient has been on escitalopram 10 mg for at least 6-8 weeks. 1, 2

Critical First Step: Verify Treatment Duration

• Ensure the patient has been on escitalopram 10 mg for a minimum of 6-8 weeks before declaring treatment failure, as this is the required duration to adequately assess SSRI efficacy 1, 2
• If less than 6-8 weeks have passed, continue current dose and reassess at the 6-8 week mark 1
• Premature dose escalation or augmentation before adequate trial duration leads to unnecessary polypharmacy and missed opportunities for response 2

Dose Optimization Strategy

Escitalopram Dosing in Elderly Patients

• The FDA-approved maximum dose for elderly patients is 10 mg daily due to 50% increased half-life compared to younger adults 3
• However, clinical trials in elderly patients with comorbid anxiety and depression used doses of 10-20 mg daily with significant efficacy and tolerability 4
• Increase gradually to 20 mg daily (not 15 mg, as this is not a standard dose) over 1-2 weeks to minimize adverse effects, particularly behavioral activation and agitation 2
• Monitor ECG if cardiac risk factors are present, as doses above 10 mg carry increased QT prolongation risk in elderly patients 2, 3

Buspirone Augmentation Protocol

• Start buspirone 5 mg twice daily and titrate to 15-20 mg three times daily (total 45-60 mg/day) over 2-4 weeks 2, 5
• The initial 5 mg twice daily dose you proposed is appropriate for initiation but represents a subtherapeutic dose 2
• Buspirone has significantly higher discontinuation rates due to adverse events (20.6%) compared to other augmentation strategies (12.5%), so close monitoring is essential 2

Evidence Supporting This Approach

Combination Therapy Efficacy

• Escitalopram augmented with cognitive-behavioral therapy (CBT) demonstrated superior response rates compared to medication alone in elderly patients with generalized anxiety disorder 6
• In a randomized trial of 73 patients ≥60 years old, escitalopram plus CBT increased response rates on worry measures, and both escitalopram and CBT prevented relapse compared to placebo 6
• Consider adding CBT to the medication regimen, as this combination addresses both neurobiological and psychological components of anxiety 2

Alternative Strategies if Current Plan Fails

• If inadequate response after 8 weeks at escitalopram 20 mg plus optimized buspirone, switch to an SNRI (duloxetine 60 mg daily or venlafaxine extended-release 75-225 mg daily) 2, 7, 5
• Duloxetine showed 50% response rate in elderly patients who failed SSRI treatment, with mean maximum dose of 93 mg/day and median time to response of 12 weeks 7
• SNRIs demonstrate statistically significantly better response rates than SSRIs in treatment-resistant cases 2

Critical Monitoring Requirements

Safety Monitoring in Elderly Patients

• Assess for suicidal ideation at every visit during the first 1-2 months after dose changes, as suicide risk is greatest during this period 1, 2
• Monitor for behavioral activation syndrome (agitation, anxiety, confusion) within 24-48 hours of dose increases 2
• Screen for hyponatremia, as SSRIs carry increased risk in elderly patients 3
• Evaluate for discontinuation syndrome if doses are missed (dizziness, anxiety, irritability, sensory disturbances), though escitalopram has lower risk than paroxetine or sertraline 2

Response Assessment Timeline

• Reassess anxiety symptoms using standardized scales (HAM-A or GAD-7) every 2-4 weeks after dose optimization 2, 5
• Allow 8-12 weeks at maximum tolerated doses before declaring treatment failure 2
• If no improvement after 6-8 weeks at optimized doses, modify treatment strategy 1

Common Pitfalls to Avoid

• Do not use 15 mg escitalopram—this is not a standard dose; use 10 mg or 20 mg 3, 4
• Do not exceed escitalopram 20 mg daily without cardiac monitoring, as higher doses increase QT prolongation risk without additional benefit 2
• Do not combine escitalopram with other serotonergic agents (including duloxetine from previous treatment) without appropriate washout period due to serotonin syndrome risk 2
• Do not stop buspirone at 10 mg/day—this is subtherapeutic; target 45-60 mg/day in divided doses 2, 5
• Do not add benzodiazepines for acute anxiety in elderly patients due to fall risk, cognitive impairment, and dependence potential 5

Duration of Continuation Therapy

• Continue treatment for 4-9 months after satisfactory response in first episode 1
• For patients with recurrent anxiety (2+ episodes), consider years to lifelong maintenance therapy 1
• Both escitalopram and CBT prevent relapse; CBT may allow sustained remission without requiring long-term pharmacotherapy 6