Maximum Recommended Dose of Buspirone (Buspar)
The maximum recommended dose of buspirone is 60 mg per day, typically divided into three doses. 1
Dosing Guidelines
Buspirone dosing follows a structured approach:
- Starting dose: 15 mg/day (5 mg three times daily)
- Titration: Increase by 5 mg every 2-3 days as needed
- Maintenance dose: 15-30 mg/day is the most common effective range
- Maximum dose: 60 mg/day
Dosing Schedule Options
- Three times daily (TID): 10 mg TID (30 mg/day) is a common effective regimen
- Twice daily (BID): 15 mg BID (30 mg/day) is equally effective with potentially better compliance 2
Pharmacokinetic Considerations
Understanding buspirone's pharmacokinetics helps explain the dosing recommendations:
- Bioavailability: Only about 4% of an oral dose reaches systemic circulation
- Half-life: Approximately 2.5 hours
- Metabolism: Extensively metabolized by the liver
- Food effect: Taking with food increases bioavailability 2-fold
- Linear pharmacokinetics: Observed in the 10-40 mg dose range 3
Safety at Higher Doses
- Long-term studies have shown that most patients are successfully managed on daily doses ranging from 15 to 30 mg/day 4
- In clinical trials, doses as high as 90 mg/day have been used safely in depression studies 5
- Healthy volunteers have tolerated single doses up to 375 mg in pharmacology trials 1
Special Populations
Dose adjustments may be necessary in:
- Hepatic impairment: Significant reduction in dosage required (plasma concentrations can be 15-fold higher)
- Renal impairment: Moderate reduction in dosage recommended (2-fold increase in plasma concentrations)
- Elderly: No specific dose adjustment required based on age alone 3
Drug Interactions
Dose reduction is necessary when buspirone is co-administered with:
- CYP3A4 inhibitors (e.g., verapamil, diltiazem, erythromycin, itraconazole)
- Avoid combination with MAO inhibitors
Overdose Considerations
While buspirone has a favorable safety profile even at higher doses, symptoms of overdose may include:
- Nausea, vomiting, dizziness
- Drowsiness, miosis
- Gastric distress
No deaths have been reported from buspirone overdose alone, and complete recovery is the usual outcome 1
Clinical Monitoring
When prescribing buspirone at higher doses:
- Monitor for side effects (dizziness, headache, nausea are most common)
- Reassess the need for continued therapy periodically
- No withdrawal syndrome has been observed after abrupt discontinuation, even after long-term use 4