What is the best approach to introduce a Selective Serotonin Reuptake Inhibitor (SSRI) or Serotonin-Norepinephrine Reuptake Inhibitor (SNRI) in a 73-year-old patient with inadequate response to buspirone (Buspar) for mood and anxiety?

Best Practice Plan for Adding SSRI/SNRI to Buspirone in a 73-Year-Old Patient

Start an SSRI at therapeutic dosing while continuing buspirone, then taper buspirone after 2-4 weeks once the SSRI reaches therapeutic effect. This approach minimizes serotonin syndrome risk while providing continuity of anxiolytic coverage during the transition period.

Immediate Action Steps

Drug Selection and Initiation

• Choose an SSRI as first-line therapy for mood and anxiety disorders in older adults, as SSRIs are recommended as first-line treatment for mood disorders by the UK National Institute for Health and Care Excellence 1.

• Use therapeutic dosing from the start rather than low doses, because therapeutic-dose SSRIs are necessary to adequately treat mood disorders alongside anxiety symptoms 1.

• SNRIs are an acceptable alternative if SSRIs are contraindicated or not tolerated, as they are beneficial for depression and anxiety, particularly in patients with psychological comorbidity 1.

Critical Safety Monitoring

Monitor closely for serotonin syndrome during the overlap period, as buspirone combined with SSRIs/SNRIs carries risk of this potentially life-threatening condition 2. Watch for:

• Mental status changes (agitation, confusion, delirium) 2
• Autonomic instability (tachycardia, labile blood pressure, hyperthermia, diaphoresis) 2
• Neuromuscular changes (tremor, rigidity, myoclonus, hyperreflexia) 2
• Gastrointestinal symptoms (nausea, vomiting, diarrhea) 2

Assess for suicidal ideation at each visit, as anxiety disorders carry increased suicide risk 3.

Transition Protocol

Week 0-2: Overlap Phase

• Start SSRI at standard therapeutic dose while maintaining buspirone 10 mg TID 1
• Schedule follow-up within 1-2 weeks to monitor for serotonin syndrome 2
• Educate patient on serotonin syndrome symptoms and instruct to seek immediate care if they occur 2

Week 2-4: Taper Phase

• Once SSRI therapeutic effects begin (typically 2-4 weeks), initiate buspirone taper 4
• Reduce buspirone by 5 mg every 3-5 days to minimize withdrawal symptoms
• Continue monitoring for anxiety symptom breakthrough during taper

Week 4+: Maintenance Phase

• Continue SSRI monotherapy at therapeutic dose 1
• Use standardized anxiety rating scales to assess treatment response 3
• If inadequate response after 6-8 weeks at therapeutic SSRI dose, consider buspirone augmentation (20-30 mg/day) as this combination has shown 59-63% response rates in treatment-resistant cases 4

Alternative Augmentation Strategy

If the patient shows partial response to SSRI after 6-8 weeks, consider re-adding buspirone as augmentation therapy rather than switching agents:

• Buspirone augmentation of SSRIs produces marked clinical improvement in 59% of initially unresponsive patients 4
• Use buspirone 20-30 mg/day divided doses for augmentation 4
• This combination is generally well-tolerated with careful monitoring for serotonin syndrome 2, 4

Concurrent Non-Pharmacologic Intervention

Strongly recommend cognitive behavioral therapy (CBT) alongside medication changes, as combination CBT plus medication produces superior outcomes to either treatment alone 3. Provide approximately 14 individual sessions over 4 months, each lasting 60-90 minutes 3.

Common Pitfalls to Avoid

• Do not use MAOIs concurrently with buspirone, as this combination is contraindicated due to risk of elevated blood pressure 2
• Do not abruptly discontinue buspirone before SSRI reaches therapeutic effect, as this creates an anxiolytic gap
• Do not use sub-therapeutic SSRI doses in older adults with mood symptoms, as low doses will not adequately treat the underlying mood disorder 1
• Do not dismiss the overlap period monitoring, as serotonin syndrome can develop even with commonly used combinations 2