Buspirone Dosage for Adults
Start buspirone at 5 mg twice daily (10 mg/day total) and titrate up to a maximum of 60 mg/day (typically 20 mg three times daily) based on clinical response. 1, 2
Initial Dosing
- Begin with 5 mg twice daily as recommended by the American Academy of Family Physicians 1, 2
- This conservative starting dose minimizes side effects while establishing baseline tolerability 3
Dose Titration
- Increase gradually based on clinical response and tolerability over the first few weeks 2
- Most patients achieve therapeutic benefit at 15-30 mg/day divided into 2-3 doses 4, 5
- The typical maintenance range is 15-30 mg/day, which was the most commonly used dosing range in long-term safety studies 5
Maximum Dosing
- The maximum recommended daily dose is 60 mg/day, typically administered as 20 mg three times daily 1, 2
- Higher doses up to 60 mg daily may be required for optimal therapeutic effect in some patients who do not respond adequately to lower doses 2
Critical Timing Considerations
- Buspirone requires 2-4 weeks to become fully effective 1, 2
- A "lag time" of 1-2 weeks to onset of anxiolytic effect has been consistently noted in clinical trials 4
- Patient counseling about this delayed onset is essential to maintain compliance during the initial treatment period 4
Food Effects
- Administration with food increases buspirone absorption 2-fold (both Cmax and AUC) 6
- For consistent dosing, administer buspirone either always with food or always without food 6
Special Population Adjustments
Hepatic Impairment
- Reduce dose substantially in hepatic impairment: plasma concentrations increase 15-fold and half-life doubles compared to healthy individuals 6
- Use caution and consider starting at lower doses with slower titration 6
Renal Impairment
- Reduce dose in renal impairment: Cmax and AUC increase 2-fold in patients with renal dysfunction 6
- Monitor closely for adverse effects 6
Elderly Patients
- No dose adjustment needed based on age alone 6
- Elderly patients (>65 years) responded well to mean doses of 18 mg/day, similar to younger adults 3
- Buspirone was well-tolerated in elderly patients receiving multiple concomitant medications for chronic conditions 3
Duration of Therapy
- Long-term use up to one year has been studied and found safe 5
- Most patients in long-term studies were successfully managed on 15-30 mg/day 5
- No withdrawal syndrome occurs upon abrupt discontinuation after more than 6 months of therapy 5
- Periodically reevaluate the need for continued therapy when used for several months or longer 5
Drug Interactions Requiring Dose Adjustment
- Substantially reduce buspirone dose when coadministered with:
- Verapamil, diltiazem, erythromycin, or itraconazole (these increase buspirone plasma concentrations substantially) 6
- Increase buspirone dose when coadministered with:
- Rifampin (decreases buspirone plasma concentrations almost 10-fold) 6