Buspar (Buspirone) Dosing
Start buspirone at 5 mg twice daily and titrate up to a target dose of 15-30 mg per day in divided doses, with a maximum of 60 mg per day (20 mg three times daily). 1
Initial Dosing
- Begin with 5 mg twice daily (BID) 1
- This starting dose minimizes initial side effects while establishing therapeutic levels 2, 3
Titration Schedule
- Increase by 5 mg every 2-3 days as tolerated to reach the target therapeutic range 2, 3
- Most patients respond to 15-30 mg per day in divided doses 4, 5
- The medication can be given either as 15 mg twice daily OR 10 mg three times daily for a 30 mg total daily dose—both regimens show equivalent efficacy 2, 3
Maximum Dosing
- Maximum dose: 60 mg per day (typically given as 20 mg three times daily) 1
- In clinical trials for generalized anxiety disorder, doses were titrated up to 45 mg per day when needed 6
Dosing Frequency Options
- Twice daily (BID) dosing offers better convenience and potentially improved compliance compared to three times daily dosing 2, 3
- No significant difference in efficacy or safety between BID and TID regimens at equivalent total daily doses 2, 3
- The only notable difference: BID dosing showed slightly higher incidence of palpitations (5% vs 1%) compared to TID 2
Important Clinical Considerations
- Onset of action requires 2-4 weeks for full therapeutic effect 1
- Patients must be counseled about this delayed onset to prevent premature discontinuation 1
- Absorption is nonlinear due to first-pass metabolism, with mean bioavailability of only 3.9% 5
- Short elimination half-life of 2.1 hours necessitates divided dosing throughout the day 5
Special Populations
- Elderly or frail patients: Start with lower doses (e.g., 2.5-5 mg) and titrate more gradually 1
- Hepatic or renal impairment: Reduce doses and monitor closely 1
Common Pitfalls to Avoid
- Do not expect immediate anxiolytic effects—unlike benzodiazepines, buspirone requires consistent dosing for 2-4 weeks before therapeutic benefits emerge 1
- Do not abruptly discontinue after long-term use—although withdrawal syndrome is rare, gradual tapering after prolonged therapy (>6 months) is prudent 4
- Most common side effects include dizziness, headache, and nausea, which typically diminish with continued use 2, 3, 6