Maximum Recommended Dose of Buspirone (Buspar)
The maximum recommended daily dose of buspirone is 60 mg per day, typically administered as 20 mg three times daily. 1
Dosing Guidelines
- Initial dosing should start at 5 mg twice daily and can be gradually increased based on clinical response and tolerability 1
- Dose increases should be made incrementally, allowing time to assess response before further increases 1
- Most patients respond to doses between 15-30 mg per day 2
- The daily dose should be divided, typically administered 2-3 times per day due to buspirone's short half-life of approximately 2.5 hours 3
- Both twice-daily (BID) and three-times-daily (TID) dosing regimens at 30 mg/day total dose have shown similar efficacy and safety profiles 4
Clinical Considerations
- Buspirone may take 2-4 weeks to achieve full therapeutic effect for anxiety symptoms 1
- No evidence of tolerance development or withdrawal syndrome has been observed even after long-term treatment (up to one year) 2
- The medication's pharmacokinetics are linear over the dose range of 10-40 mg 3
- Food increases the bioavailability of buspirone approximately 2-fold, so consistent administration with respect to meals is recommended 3
Special Populations
- Patients with hepatic impairment may require lower doses as they experience 15-fold higher plasma concentrations and twice the half-life compared to healthy individuals 3
- Patients with renal impairment may need dose adjustment as they experience 2-fold increases in peak concentration and area under the curve 3
- Elderly patients have shown good response to buspirone at doses similar to younger adults (mean dose 18 mg/day in studies), with good tolerability even with concomitant medications for other conditions 5
Drug Interactions
- Significant increases in buspirone plasma concentrations occur with co-administration of CYP3A4 inhibitors such as verapamil, diltiazem, erythromycin, and itraconazole 3
- CYP3A4 inducers like rifampin can decrease buspirone plasma concentrations up to 10-fold 3
- Dose adjustments may be necessary when starting or stopping medications that affect CYP3A4 enzyme activity 3
While some studies have investigated higher doses (up to 90 mg daily) for specific conditions like major depression 6, the standard maximum recommended daily dose remains 60 mg per day for anxiety disorders 1.