Maximum Dose of Buspirone
The maximum recommended dose of buspirone is 60 mg per day, typically administered as 20 mg three times daily. 1
Dosing Algorithm
Initial Dosing
- Start at 15 mg daily (7.5 mg twice daily) as recommended by the FDA 1
- Alternative starting approach: 5 mg twice daily (10 mg/day total) to minimize side effects while establishing tolerance 2
Dose Titration
- Increase by 5 mg per day every 2-3 days as needed to achieve therapeutic response 1, 2
- The standard therapeutic range is 15-30 mg per day in divided doses, which successfully manages most patients 2, 3
- Continue titration until therapeutic effect is achieved or the maximum dose is reached 2
Maximum Dosing
- Absolute maximum: 60 mg per day (20 mg three times daily) 1, 2, 4
- This maximum applies whether buspirone is used as monotherapy for anxiety or as an augmenting agent 4
Critical Timing Considerations
- Onset of action requires 2-4 weeks, which is essential for patient counseling to maintain compliance 2, 4
- Some studies note a "lagtime" of 1-2 weeks before anxiolytic effects become apparent 5
- Patients must be counseled upfront about this delayed onset to prevent premature discontinuation 2
Food Effects and Administration
- Bioavailability increases 2-fold when taken with food 1, 6
- Patients should take buspirone consistently either always with food or always without food to maintain stable plasma levels 1
Special Population Adjustments
Hepatic Impairment
- Substantially reduce the dose in patients with hepatic impairment 2
- Plasma concentrations can be 15-fold higher in hepatic impairment, with doubled half-life 6
Renal Impairment
Elderly or Frail Patients
- Start at 2.5-5 mg twice daily and titrate more gradually 2
Drug Interaction Dosing Modifications
- CYP3A4 inhibitors (verapamil, diltiazem, erythromycin, itraconazole) substantially increase buspirone plasma concentrations and require dose reduction 1, 6
- Rifampin decreases buspirone concentrations almost 10-fold, potentially requiring dose increases 6
Discontinuation
- No withdrawal syndrome occurs after abrupt discontinuation, even after more than 6 months of therapy 3
- This distinguishes buspirone from benzodiazepines, which require tapering 3
Common Pitfall to Avoid
The most critical error is failing to counsel patients about the 2-4 week delay in therapeutic effect 2, 4. Patients expecting immediate anxiolytic effects (like with benzodiazepines) may discontinue therapy prematurely, leading to treatment failure despite using an appropriate medication at adequate doses.