Starting Dose of Buspirone in Adults
The recommended starting dose of buspirone (BuSpar) for adults is 5 mg twice daily (10 mg/day total). 1
Dosing Guidelines
- Initial dosage should be 5 mg twice daily (10 mg/day) for anxiety management 1
- Dose can be gradually increased based on clinical response 1
- Typical maintenance dose ranges from 15-30 mg/day (divided into multiple doses) 2
- Maximum recommended dose is 60 mg/day (20 mg three times daily) 1
- Most patients are successfully managed on daily doses ranging from 15 to 30 mg/day 2
Important Clinical Considerations
Onset of Action
- Buspirone may take 2-4 weeks to become fully effective for anxiety symptoms 1
- Unlike benzodiazepines, buspirone does not provide immediate relief of anxiety symptoms 1
Administration Considerations
- Can be administered in either BID (twice daily) or TID (three times daily) regimens with similar efficacy and safety profiles 3
- Food increases the bioavailability of buspirone, with Cmax and AUC increasing approximately 2-fold when taken with food 4
Special Populations
- Elderly patients can typically use the same starting dose (5 mg twice daily), with a mean effective dose of 18 mg/day 5
- Dose adjustments are necessary for patients with renal or hepatic impairment 4:
- Renal impairment: Cmax and AUC increased 2-fold
- Hepatic impairment: Cmax and AUC increased 15-fold; half-life doubled
Drug Interactions
- Significant interactions occur with CYP3A4 inhibitors and inducers 4:
- Verapamil, diltiazem, erythromycin, and itraconazole substantially increase buspirone plasma concentrations
- Rifampin decreases buspirone plasma concentrations by approximately 10-fold
Monitoring and Follow-up
- Regular assessment of therapeutic response is recommended 2
- No evidence of withdrawal syndrome when buspirone is discontinued after long-term use 2
- For chronic anxiety requiring treatment beyond several months, periodic reevaluation of the need for continued therapy is recommended 2