Starting Dose for Buspirone
The recommended starting dose for buspirone is 5 mg twice daily, with a maximum dose of 20 mg three times daily. 1
Dosing Guidelines
- Initial dosage should be 5 mg twice daily 1
- Gradual dose titration is recommended to minimize side effects and optimize therapeutic benefit 2
- Maximum recommended dose is 20 mg three times daily (60 mg total daily dose) 1
- Therapeutic effects may take 2-4 weeks to become evident, requiring patient education about this delayed onset of action 1
Clinical Considerations
- Buspirone is useful for patients with mild to moderate anxiety/agitation 1
- Unlike benzodiazepines, buspirone:
Special Populations
- For elderly or frail patients, consider starting at a lower dose and titrating more gradually 2
- Patients with hepatic impairment may require dose adjustment as buspirone concentrations can be up to 15-fold higher compared to healthy individuals 2
- Patients with renal impairment may need dose adjustment as drug concentrations can be approximately 2-fold higher 2
Pharmacokinetic Considerations
- Buspirone has a short half-life of approximately 2.5 hours 2
- Bioavailability is low (approximately 4%) 2
- Taking with food can increase peak concentration and area under the curve by 2-fold 2
- The drug is extensively metabolized, with 1-pyrimidinylpiperazine (1-PP) being a major metabolite that may contribute to its pharmacological activity 2
Drug Interactions
- Significant increases in buspirone plasma concentrations can occur with concurrent use of:
- Verapamil
- Diltiazem
- Erythromycin
- Itraconazole 2
- Rifampin can decrease buspirone plasma concentrations by approximately 10-fold 2
Dosing Flexibility
- For patient convenience and potentially improved compliance, a twice-daily (BID) regimen of 15 mg twice daily is comparable in safety and tolerability to a three-times-daily (TID) regimen of 10 mg three times daily 4
- Most patients can be successfully managed on daily doses ranging from 15 to 30 mg/day 5