Buspirone for Generalized Anxiety Disorder
For generalized anxiety disorder (GAD), start buspirone at 5 mg twice daily and titrate to a maximum of 20 mg three times daily (60 mg/day total), recognizing that therapeutic effects require 2-4 weeks to manifest. 1
Dosing Algorithm
Initial dosing:
Target dosing:
- Effective range: 15-30 mg/day for most patients 3, 5
- Maximum dose: 20 mg three times daily (60 mg/day total) 2, 1
- Can be administered as either BID or TID regimens with equivalent efficacy 3, 6
Titration schedule:
- Increase dosage every 2-3 days as tolerated 4
- Higher doses (up to 45 mg/day) may be used in patients with coexisting mild depressive symptoms 4
Clinical Efficacy Profile
Onset of action:
- Therapeutic effects delayed 2-4 weeks after initiation 2, 1
- This lagtime requires patient counseling to maintain compliance 5
- Patients must not expect immediate relief like with benzodiazepines 7
Demonstrated efficacy:
- Superior to placebo in reducing HAM-A scores by approximately 12.4 points versus 9.5 points with placebo 4
- Comparable efficacy to benzodiazepines (diazepam, clorazepate, alprazolam, lorazepam) 7, 5
- FDA-approved for GAD management and short-term anxiety symptom relief 8
Specific Patient Populations
Ideal candidates:
- Patients with mild to moderate anxiety 2, 1
- Chronic anxiety requiring long-term treatment 7
- Elderly patients (safer profile than benzodiazepines) 7
- GAD with coexisting mild depressive symptoms (HAM-D scores 12-17) 4
- Patients requiring daytime alertness 5
Less suitable:
- Panic disorder (evidence inconclusive, not routinely recommended) 7
- Patients demanding immediate symptom relief 7
Safety and Tolerability
Common adverse effects:
- Dizziness, headache, and nausea are most frequent 6
- Significantly less sedation than benzodiazepines 5
- BID dosing associated with slightly higher palpitations (5% vs 1%) and amblyopia compared to TID 3, 6
- Buspirone-treated patients report more nausea, dizziness, somnolence, and sweating than placebo 4
Key advantages over benzodiazepines:
- No hypnotic, anticonvulsant, or muscle relaxant properties 5
- No psychomotor or cognitive impairment 5
- No additive effects with alcohol 5
- Limited abuse and dependence potential 5
- No tolerance development with chronic use 7
Duration of Treatment
Treatment monitoring:
- Efficacy demonstrated in controlled trials for 3-4 weeks 8
- Long-term use (up to 1 year) studied in 264 patients without ill effects 8
- Periodically reassess need for continued treatment in extended use 8
- Average symptom duration in studied patients was 6 months prior to treatment 8
Augmentation Strategy Context
When used as augmentation in major depressive disorder after initial SSRI failure, buspirone shows similar efficacy to bupropion and cognitive therapy, though bupropion causes fewer discontinuations due to adverse events (12.5% vs 20.6%) 2, 1