Buspirone Initial Dosing Regimen
The recommended initial dosing regimen for buspirone is 15 mg daily divided into two doses (7.5 mg twice daily), which can be titrated upward by 5 mg per day every 2-3 days as needed, with a maximum daily dose of 60 mg. 1
Dosing Details
- Starting dose: 7.5 mg twice daily (15 mg total daily dose)
- Titration: Increase by 5 mg per day every 2-3 days based on clinical response
- Target dose: 20-30 mg per day in divided doses is commonly effective
- Maximum dose: 60 mg per day
- Administration: Take consistently either always with food or always without food (bioavailability increases when taken with food)
Special Considerations
Drug Interactions
- When buspirone is given with potent CYP3A4 inhibitors (e.g., verapamil, diltiazem, erythromycin, itraconazole), dosage adjustment is necessary as these medications can substantially increase buspirone plasma concentrations 1, 2
- Allow at least 14 days between discontinuation of an MAOI and initiation of buspirone therapy 1
- Similarly, allow at least 14 days after stopping buspirone before starting an MAOI 1
Patient-Specific Factors
- Hepatic impairment: Lower doses are recommended as buspirone concentrations can be 15-fold higher with a doubled half-life compared to healthy individuals 2
- Renal impairment: Consider dose reduction as concentrations may be 2-fold higher 2
- Food effects: Bioavailability increases 2-fold when taken with food, so consistency in administration (either always with or always without food) is important 1, 2
Clinical Pearls
- Onset of anxiolytic effect may take 1-2 weeks, so patient education regarding this "lag time" is important for compliance 3
- Unlike benzodiazepines, buspirone lacks hypnotic, anticonvulsant, and muscle relaxant properties 3
- Buspirone has a low incidence of sedation compared to benzodiazepines, making it advantageous for patients who need to maintain daytime alertness 3
- Most patients can be successfully managed on daily doses ranging from 15 to 30 mg/day 4
- Buspirone can be administered as either twice daily (BID) or three times daily (TID) with similar safety profiles, though BID dosing may offer greater convenience and potentially better compliance 5
Monitoring
- Assess therapeutic response after 2-3 weeks of treatment
- Periodically reevaluate the need for continued therapy, especially if used for several months or longer 4
- Monitor for common side effects: dizziness, headache, and nausea 5
Buspirone offers an effective anxiolytic option with advantages over benzodiazepines in terms of sedation profile and abuse potential, making it particularly suitable for patients who need to maintain alertness during daily activities.