Buspar (Buspirone) Dosing for Adult Anxiety
Start buspirone at 5 mg twice daily and titrate upward by 5 mg/day every 2-3 days to reach a target dose of 15-30 mg/day in divided doses, with a maximum of 60 mg/day if needed. 1
Standard Dosing Algorithm
- Initial dose: 5 mg orally twice daily 1
- Titration schedule: Increase by 5 mg/day every 2-3 days based on clinical response 1
- Target therapeutic range: 15-30 mg/day in divided doses (either twice or three times daily) 1, 2
- Maximum dose: 60 mg/day, though this is rarely needed 1
The twice-daily regimen (15 mg BID) offers equivalent efficacy and safety compared to three-times-daily dosing (10 mg TID), with the potential advantage of improved compliance 3. Taking the second dose earlier in the day rather than late evening can minimize insomnia risk 1.
Critical Timing Expectations
Buspirone requires 2-4 weeks of continuous daily dosing to achieve full therapeutic effect and has no immediate anxiolytic action 1, 2. This delayed onset is a critical counseling point—patients must understand this is not a PRN medication and cannot provide immediate relief like benzodiazepines 2.
- Assess clinical response only after 2-4 weeks of treatment, not earlier 1
- The medication must be taken on a scheduled basis to maintain efficacy 2
- Buspirone is inappropriate for acute anxiety requiring immediate relief 1
Special Population Adjustments
Hepatic Impairment
Buspirone administration cannot be recommended in patients with severe hepatic impairment 4. Patients with hepatic dysfunction show a 13-fold increase in steady-state AUC compared to healthy subjects, with reduced clearance and prolonged half-life 4.
Renal Impairment
Buspirone administration cannot be recommended in patients with severe renal impairment 4. Patients with renal impairment (creatinine clearance 10-70 mL/min/1.73 m²) demonstrate a 4-fold increase in steady-state AUC compared to healthy subjects 4.
Elderly Patients
Buspirone is particularly well-suited for elderly patients due to its lack of sedation, cognitive impairment, and fall risk compared to benzodiazepines 1. A mean dose of 18 mg/day (range 5-30 mg/day) has proven effective and well-tolerated in patients over 65 years 1, 5. No dose adjustment is required based on age alone, as pharmacokinetics remain similar between elderly and younger patients 4.
Food Effects on Bioavailability
Food significantly increases buspirone absorption—the AUC and peak plasma concentration increase by 84% and 116%, respectively, when taken with food 4. For consistent therapeutic effect, advise patients to take buspirone either always with food or always without food 4.
Common Prescribing Pitfalls to Avoid
- Do not start at too high a dose—this increases side effects without providing faster benefit 1
- Do not discontinue prematurely before the 2-4 week therapeutic window 1
- Do not prescribe buspirone PRN—it has no immediate anxiolytic action and requires continuous daily dosing 2
- Do not use for severe agitation or acute panic—buspirone is only effective for mild-to-moderate generalized anxiety 1
Adverse Effects Profile
The most frequently reported adverse events include dizziness, headache, and nausea 3. Buspirone causes significantly less sedation than benzodiazepines and does not impair psychomotor or cognitive function 6. Palpitations may occur more frequently with twice-daily dosing (5%) compared to three-times-daily dosing (1%) 3.
Long-Term Safety
Buspirone can be safely used for up to one year when clinically indicated, with most patients successfully managed on 15-30 mg/day 7. Abrupt discontinuation after more than six months of therapy produces no evidence of withdrawal syndrome 7. The medication has limited potential for abuse and dependence 6.