Buspirone Dosing Guidelines
The recommended dosing for buspirone is to start at 5 mg twice daily and can be increased to a maximum of 20 mg three times daily, with most patients effectively managed on 15-30 mg per day. 1
Initial Dosing and Titration
- Initial dose: 5 mg twice daily
- Titration: Increase gradually using increments of initial dose every 5-7 days
- Maximum dose: 20 mg three times daily (60 mg total daily dose)
- Typical effective dose range: 15-30 mg per day
Special Considerations
Timing of Effect
- Buspirone may take 2-4 weeks to become effective for anxiety 1
- Unlike benzodiazepines, buspirone does not provide immediate relief of anxiety symptoms
- Patients should be informed about this delayed onset to set appropriate expectations
Administration Considerations
- Food increases buspirone bioavailability approximately 2-fold 2
- Consistent administration with respect to meals is recommended to maintain steady drug levels
Dosing in Special Populations
Hepatic Impairment
- Significantly higher drug exposure (15-fold increase in plasma concentration) in patients with hepatic impairment 2
- Consider lower doses and careful titration in patients with liver disease
Renal Impairment
- Approximately 2-fold increase in drug exposure in patients with renal impairment 2
- Dose reduction may be necessary
Drug Interactions
- Significant interactions with CYP3A4 inhibitors:
- Verapamil, diltiazem, erythromycin, and itraconazole substantially increase buspirone plasma concentrations 2
- Dose reduction may be necessary when used with these medications
- Rifampin decreases buspirone plasma concentrations by approximately 10-fold 2
- Higher doses may be required if co-administered
Efficacy and Safety
Long-term Use
- Buspirone has demonstrated safety for treatment periods up to one year 3
- No withdrawal syndrome observed when discontinued after 6+ months of therapy 3
- Periodic reevaluation of the need for continued therapy is recommended for long-term use 3
Common Side Effects
- Most frequent adverse events: dizziness, headache, and nausea 4
- Less sedating than benzodiazepines
- No significant psychomotor impairment or cognitive effects 5
Dosing Schedule Options
- BID (twice daily) dosing is as effective and safe as TID (three times daily) dosing 4
- BID dosing may improve medication adherence
Clinical Pearls
- Buspirone is useful only for mild to moderate agitation/anxiety 1
- Unlike benzodiazepines, buspirone does not cause tolerance, addiction, or cognitive impairment
- Patients previously treated with benzodiazepines may perceive buspirone as less effective due to lack of immediate sedative effects 5
- Higher doses (up to 90 mg/day) have been studied and found to be safe in certain populations 6, though standard dosing is typically sufficient
Remember that buspirone has a delayed onset of action compared to benzodiazepines, which may affect patient perception of efficacy and adherence to therapy.