Buspirone (Buspar) Dosing Recommendations
The recommended dosing for Buspar (buspirone) is 15-30 mg daily, divided into 2-3 doses, with a starting dose of 5 mg three times daily and gradual titration to minimize side effects. 1
Initial Dosing and Titration
- Starting dose: 5 mg three times daily (15 mg/day)
- Titration: Increase by 5 mg/day every 2-3 days as needed and tolerated
- Target dose range: 15-30 mg/day
- Maximum dose: 60 mg/day (rarely needed)
- Dosing frequency: Typically divided into 2-3 doses per day
Administration Considerations
- Can be administered as twice daily (BID) or three times daily (TID) dosing:
- 15 mg BID (morning and evening)
- 10 mg TID (morning, afternoon, and evening)
- Take with or without food (note: food increases absorption 2-fold) 2
- Can be taken at bedtime or with meals to minimize gastrointestinal side effects
Special Populations
Elderly Patients
- No specific dose adjustment required based solely on age 3
- Consider starting at the lower end of the dosing range (7.5-10 mg/day)
Hepatic Impairment
- Use with caution - plasma concentrations can be 15-fold higher 2
- Start with 2.5 mg once or twice daily
- Titrate slowly based on response and tolerability
Renal Impairment
- Use with caution - plasma concentrations can be 2-fold higher 2
- Consider starting at 2.5 mg twice daily
- Titrate slowly based on response and tolerability
Drug Interactions
Dose Reduction Required
When co-administered with the following medications, reduce buspirone dose to 2.5 mg once or twice daily 1:
- CYP3A4 inhibitors: erythromycin, itraconazole, nefazodone
- Calcium channel blockers: diltiazem, verapamil
- Grapefruit juice (avoid large amounts)
Dose Increase May Be Required
When co-administered with CYP3A4 inducers, buspirone dose may need to be increased 1:
- Rifampin
- Dexamethasone
- Phenytoin, phenobarbital, carbamazepine
Duration of Treatment
- Evaluate response after 3-4 weeks of treatment at therapeutic dose
- For chronic anxiety, periodically reassess the need for continued therapy
- Long-term treatment (up to one year) has been shown to be safe and effective 4
- No withdrawal syndrome observed after abrupt discontinuation following long-term use 4
Monitoring Parameters
- Assess therapeutic response and side effects at follow-up visits
- Most common side effects: dizziness, headache, nausea 5
- No routine laboratory monitoring required
Clinical Pearls
- Unlike benzodiazepines, buspirone:
- Has no significant abuse potential
- Does not cause physical dependence
- Does not cause withdrawal symptoms upon discontinuation
- Has no significant sedative effects
- Full therapeutic effect may take 2-4 weeks to develop
- Buspirone has been used at doses up to 90 mg/day in clinical trials for depression 6
Buspirone is most effective when taken consistently rather than on an as-needed basis due to its delayed onset of anxiolytic effect.