Buspirone Administration Timing: Day vs Night
Buspirone should be taken twice daily (morning and evening) or three times daily (throughout the day) rather than exclusively at night, with an initial recommended dose of 15 mg daily (7.5 mg twice daily). 1
Dosing Schedule
- Buspirone is typically administered in divided doses throughout the day rather than as a single nighttime dose 2
- The FDA-approved dosing recommendation is to start with 15 mg daily divided into two doses (7.5 mg twice daily) 1
- Dosage may be increased by 5 mg per day at 2-3 day intervals as needed, with maximum daily dosage not exceeding 60 mg 1
- Common effective dosing regimens in clinical trials were 20-30 mg per day in divided doses 1
Administration Options
- Twice daily (BID) regimen: 15 mg twice daily (morning and evening) 3
- Three times daily (TID) regimen: 10 mg three times daily (throughout the day) 3
- Both regimens have similar safety profiles, though the twice daily regimen may offer better convenience and compliance 3
Clinical Considerations
- Unlike sedating anxiolytics, buspirone does not cause significant daytime drowsiness, making it suitable for daytime administration 4, 5
- Buspirone has a short half-life of approximately 2.5 hours, supporting the need for multiple daily doses rather than a single nighttime dose 6
- The onset of anxiolytic effect may take 1-2 weeks, unlike the immediate effects of benzodiazepines 4
- Buspirone should be taken consistently with regard to food intake (either always with or always without food) as food increases its bioavailability 1
Special Populations
- For patients with hepatic impairment, dosage adjustment may be necessary as the drug's half-life is doubled and plasma concentrations can be 15-fold higher 6
- For elderly patients with anxiety, buspirone may be particularly appropriate due to its favorable side effect profile compared to benzodiazepines 7
Potential Pitfalls
- Buspirone is not effective for immediate relief of anxiety symptoms and requires consistent daily dosing for 2-4 weeks to achieve therapeutic effect 2, 4
- Unlike benzodiazepines, buspirone is not indicated for as-needed or exclusively nighttime use 4, 7
- Patients switching from benzodiazepines to buspirone may experience temporary worsening of anxiety if expecting immediate relief 7
- Drug interactions with CYP3A4 inhibitors (like erythromycin, itraconazole) can substantially increase buspirone plasma concentrations, requiring dosage adjustment 6
In conclusion, buspirone should be administered in divided doses during the day rather than exclusively at night, with most regimens using either twice daily or three times daily dosing schedules to maintain therapeutic levels throughout the 24-hour period.