Buspirone Starting Dose for Adults
The recommended initial dose of buspirone for adults is 15 mg daily, administered as 7.5 mg twice daily (b.i.d.). 1
Dosing Guidelines
Initial Dosing
- Start with 15 mg daily (7.5 mg twice daily) 1
- Take consistently with regard to food (either always with or always without food) 1
- Food increases bioavailability approximately 2-fold 2
Dose Titration
- After initial dosing, may increase by 5 mg per day at intervals of 2-3 days as needed 1
- Typical effective dose range: 15-30 mg per day 3
- Maximum daily dose should not exceed 60 mg per day 1
Special Populations
Elderly Patients
- Initial dose may be lower (5 mg twice daily or 10 mg daily) 4
- Mean effective dose in elderly patients is approximately 18 mg/day 4
- Elderly patients generally respond to doses similar to younger adults 4
Patients with Hepatic Impairment
- Use lower doses due to significantly higher drug exposure (up to 15-fold) 2
- Half-life is doubled in patients with hepatic impairment 2
Patients with Renal Impairment
- Consider lower doses as drug exposure may be doubled 2
Administration Considerations
Drug Interactions
- When co-administered with CYP3A4 inhibitors (verapamil, diltiazem, erythromycin, itraconazole), lower buspirone doses are required 1, 2
- Allow at least 14 days between discontinuation of MAOIs and initiation of buspirone 1
- Rifampin can decrease buspirone plasma concentrations by approximately 10-fold 2
Clinical Pearls
- Onset of anxiolytic effect may take 2-4 weeks 5
- No evidence of withdrawal syndrome when discontinued after long-term use 3
- Buspirone is extensively metabolized with an elimination half-life of about 2.5 hours 2
- Absolute bioavailability is approximately 4% 2
Common Side Effects
- Lightheadedness, headache, and dyspepsia are common side effects 6
- Generally well-tolerated at recommended doses 3, 4
Follow-up and Monitoring
- Periodically reevaluate the need for continued therapy, especially when used for several months or longer 3
- Monitor for clinical response and side effects
Buspirone offers the advantage of being non-sedating and having no potential for dependence or withdrawal, making it particularly suitable for long-term anxiety management when indicated.