Buspirone Dosing Recommendations
Start buspirone at 5 mg twice daily (10 mg/day total), increase by 5 mg/day every 2-3 days as tolerated, target 15-30 mg/day in divided doses, with a maximum of 60 mg/day. 1
Standard Dosing Algorithm
Initial Dose
- Begin with 5 mg orally twice daily (10 mg/day total) 1
- This starting dose applies to most adult patients with anxiety 1
Titration Schedule
- Increase by 5 mg/day every 2-3 days based on response and tolerability 1
- This gradual escalation minimizes side effects while achieving therapeutic benefit 1
- Most patients reach their target dose within 1-2 weeks of initiation 1
Target Therapeutic Dose
- 15-30 mg/day in divided doses (typically 7.5-15 mg twice daily or three times daily) 1
- The average effective daily dose in clinical practice is 15-20 mg/day 2, 3
- Divide the total daily dose into 2-3 administrations for optimal effect 1
Maximum Dose
- 60 mg/day (20 mg three times daily) is the FDA-approved maximum 1
- Higher doses have been studied but offer no additional benefit and increase side effects 1
Critical Timing Consideration
Counsel patients that buspirone requires 2-4 weeks to achieve full anxiolytic effect 1, 4. This delayed onset is the most common reason for treatment failure, as patients may discontinue prematurely thinking the medication is ineffective. Unlike benzodiazepines, buspirone does not provide immediate relief 4.
Special Population Adjustments
Elderly Patients
- Start at 5 mg twice daily with no mandatory dose reduction based on age alone 1, 4
- Pharmacokinetics are not significantly affected by age 5
- For frail elderly patients, maintain the lower starting dose and titrate more cautiously 4
Hepatic Impairment
- Reduce dose substantially in patients with hepatic impairment 5
- Plasma concentrations increase 15-fold and half-life doubles in hepatic dysfunction 5
- Consider starting at 2.5-5 mg twice daily and titrating very slowly, with a lower maximum dose 5
Renal Impairment
- Reduce dose by approximately 25-50% in moderate to severe renal impairment 5
- Peak concentrations and AUC increase 2-fold in renal dysfunction 5
- Monitor closely for side effects and adjust based on tolerability 5
Important Clinical Considerations
Food Effects
- Administration with food increases buspirone absorption 2-fold 5
- Advise consistent administration (always with food or always without food) to maintain stable plasma levels 5
Drug Interactions
- Avoid or reduce dose significantly when co-administered with CYP3A4 inhibitors (verapamil, diltiazem, erythromycin, itraconazole), which substantially increase buspirone levels 5
- Rifampin decreases buspirone concentrations nearly 10-fold; consider alternative anxiolytic if rifampin is necessary 5
Discontinuation
- No tapering required even after prolonged use (up to one year) 3
- Abrupt discontinuation produces no withdrawal syndrome or rebound anxiety 3
- This distinguishes buspirone from benzodiazepines and is a significant safety advantage 3