Maximum Dose of Buspar (Buspirone) for Anxiety
The maximum recommended dose of buspirone for anxiety is 60 mg per day, typically administered as 20 mg three times daily. 1
Dosing Algorithm
Starting Dose
- Begin with 5 mg twice daily (10 mg/day total) 1
- This conservative starting dose minimizes side effects while establishing tolerance
Titration Schedule
- Increase by 5 mg increments every 2-3 days until therapeutic effect is achieved 1
- The standard therapeutic range is 15-30 mg per day in divided doses 1, 2
- Most patients respond adequately to 15-30 mg/day 2, 3
Maximum Dosing
- Absolute maximum: 60 mg per day (20 mg three times daily) 1
- Higher doses up to 90 mg/day have been studied in major depression but are not standard for anxiety 4
- The typical maximum for anxiety remains 60 mg/day in clinical practice
Dosing Frequency Options
Two acceptable regimens for 30 mg/day:
- 15 mg twice daily (BID) - may offer better compliance 3
- 10 mg three times daily (TID) - traditional dosing 1, 3
Both regimens show similar efficacy and tolerability, though the BID regimen had slightly higher palpitations (5% vs 1%) 3
Critical Clinical Considerations
Onset of Action
- Expect 2-4 weeks for full anxiolytic effect 1
- This delayed onset requires patient counseling to maintain compliance 2
- Unlike benzodiazepines, buspirone provides no immediate relief
Special Populations Requiring Dose Reduction
Hepatic impairment:
- Buspirone concentrations increase 15-fold in hepatic disease 5
- Half-life doubles in hepatic impairment 5
- Reduce dose substantially and monitor closely
Renal impairment:
- Cmax and AUC increase 2-fold 5
- Use lower doses and titrate cautiously
Elderly or frail patients:
- Start with lower doses (e.g., 2.5-5 mg twice daily) 1
- Titrate more gradually
Important Drug Interactions Affecting Dosing
Reduce buspirone dose when co-administered with:
- Verapamil, diltiazem, erythromycin, or itraconazole - these substantially increase buspirone levels 5
Increase buspirone dose when co-administered with:
- Rifampin decreases buspirone concentrations nearly 10-fold 5
Common Pitfalls to Avoid
Discontinuing too early: Patients may abandon therapy before the 2-4 week onset period; emphasize this timeline upfront 1, 2
Switching from benzodiazepines: Buspirone shows reduced efficacy in patients with chronic benzodiazepine exposure 6. It is not cross-tolerant with benzodiazepines and cannot substitute for them during withdrawal 6
Food effects: Administration with food doubles Cmax and AUC 5. Maintain consistent timing relative to meals for stable drug levels.
Expecting sedation: Unlike benzodiazepines, buspirone causes minimal sedation and does not impair psychomotor function 2. Patients expecting immediate calming effects will be disappointed.