Therapeutic Dosing of Buspirone
The recommended therapeutic dose of buspirone is 5 mg twice daily initially, with gradual titration to a target dose of 15-30 mg daily in divided doses, with a maximum of 60 mg daily. 1
Initial Dosing and Titration
- Starting dose: 5 mg twice daily
- Titration: Increase by 5 mg/day every 2-3 days as needed and tolerated
- Target dose: 15-30 mg/day divided into 2-3 doses
- Maximum dose: 60 mg/day (rarely needed)
Dosing Schedule Options
- BID regimen: 15 mg twice daily (30 mg total) - More convenient for patients 2
- TID regimen: 10 mg three times daily (30 mg total) - Similar efficacy but may have slightly better tolerability for certain side effects 2
Special Populations
Elderly Patients
- Start at lower doses (5 mg twice daily)
- Effective at mean doses of 18 mg/day in elderly patients 3
- Well-tolerated in elderly patients with concomitant medical conditions
Patients with Hepatic Impairment
- Reduce dose by 25-50%
- Avoid in severe hepatic impairment
- Buspirone has 15-fold higher plasma concentrations in patients with hepatic impairment 4
Patients with Renal Impairment
- Reduce dose by 25-50%
- Buspirone shows 2-fold higher plasma concentrations in renal impairment 4
Pharmacokinetic Considerations
- Bioavailability: Only about 4% due to extensive first-pass metabolism 4
- Half-life: Approximately 2.5 hours 4
- Food effect: Taking with food increases absorption 2-fold 4
- Drug interactions:
- Significant increases in buspirone levels with verapamil, diltiazem, erythromycin, and itraconazole
- Significant decreases with rifampin 4
Clinical Pearls
- Onset of action: Unlike benzodiazepines, buspirone may take 1-2 weeks to show anxiolytic effects 5
- Duration of therapy: For chronic anxiety, reevaluate the need for continued therapy periodically 6
- Discontinuation: No evidence of withdrawal syndrome when discontinued after long-term use 6
- Advantages: Less sedation compared to benzodiazepines; no significant cognitive or psychomotor impairment 5
Monitoring
- Assess therapeutic response after 2-4 weeks
- Monitor for common side effects: dizziness, headache, and nausea 2
- No significant effects on vital signs, ECG, or laboratory values at therapeutic doses 2
Buspirone offers an effective non-benzodiazepine option for treating anxiety with minimal sedation and low abuse potential. The therapeutic dose should be individualized within the 15-30 mg daily range based on response and tolerability.