What is the recommended titration schedule for Buspar (buspirone) in a patient with a history of anxiety, considering factors such as age, renal function, and hepatic function?

Buspar (Buspirone) Titration

Start buspirone at 5 mg twice daily and increase by 5 mg per day every 2-3 days as tolerated, targeting a usual effective dose of 15-30 mg/day divided twice daily, with a maximum of 60 mg/day (20 mg three times daily). 1

Standard Titration Schedule

Initial dosing:

• Begin with 5 mg twice daily (10 mg/day total) 1
• This starting dose minimizes initial side effects while establishing baseline tolerance 2

Dose escalation:

• Increase by 5 mg/day every 2-3 days as tolerated 1
• Target maintenance dose: 15-30 mg/day in divided doses (typically twice daily) 1, 2
• Maximum dose: 60 mg/day (20 mg three times daily) 1

Example titration:

• Days 1-3: 5 mg twice daily (10 mg/day)
• Days 4-6: 7.5 mg twice daily (15 mg/day)
• Days 7-9: 10 mg twice daily (20 mg/day)
• Continue increasing by 5 mg/day every 2-3 days until therapeutic response or maximum tolerated dose 1

Special Population Adjustments

Elderly or frail patients:

• Start with 2.5 mg twice daily 1
• Titrate more gradually using smaller increments 1
• Although pharmacokinetics are unchanged with age, greater sensitivity may occur in some older patients 2

Hepatic impairment:

• Severe hepatic impairment is a contraindication - buspirone levels increase 15-fold and half-life doubles 2, 3
• Mild-moderate impairment: reduce dose and titrate more slowly with close monitoring 2

Renal impairment:

• Severe renal impairment is a contraindication - Cmax and AUC increase 2-fold 2, 3
• Mild-moderate impairment: reduce dose and monitor closely 2

Critical Clinical Considerations

Delayed onset of action:

• Therapeutic effects typically require 2-4 weeks to manifest 1, 4
• Patient counseling about this "lagtime" is essential for medication adherence 4, 5
• This differs markedly from benzodiazepines and requires patient motivation 4, 5

Food effects:

• Administration with food increases Cmax and AUC 2-fold 3
• Maintain consistent timing relative to meals for stable plasma levels 3

Drug interactions requiring dose adjustment:

• Strong CYP3A4 inhibitors (verapamil, diltiazem, erythromycin, itraconazole): substantially increase buspirone levels - reduce buspirone dose 3
• Rifampin: decreases buspirone levels 10-fold - may require dose increase 3
• Cimetidine and alprazolam have negligible effects 3

Monitoring and Duration

Assessment timeline:

• Evaluate response after 2-4 weeks at target dose 1
• Most patients respond to 15-30 mg/day 6
• Long-term use up to one year has demonstrated safety without withdrawal syndrome upon discontinuation 6

Common pitfalls:

• Premature discontinuation before 2-4 weeks due to lack of immediate effect 4, 5
• Inadequate patient education about delayed onset 4, 5
• Failure to adjust for hepatic/renal impairment 2
• Not accounting for food effects on absorption 3

Discontinuation:

• No withdrawal syndrome reported even after abrupt discontinuation following >6 months of therapy 6
• However, periodic reevaluation of need for continued therapy is recommended 6