What is the starting dose of Buspar (buspirone) for adults?

Starting Dose of Buspirone for Adults

The recommended starting dose of buspirone (BuSpar) for adults is 5 mg taken three times daily (15 mg/day total). This is the appropriate initial dosing regimen that balances efficacy with tolerability for most adult patients.

Dosing Guidelines

Initial Dosing

• Start with 5 mg three times daily (15 mg/day total)
• Administer at regular intervals to maintain consistent blood levels
• Take with or without food (note that food increases bioavailability)

Dose Titration

• After 7-10 days, assess response and tolerability
• If needed, increase dose by 5 mg/day at intervals of 2-3 days
• Most patients respond to doses between 15-30 mg/day
• Maximum recommended daily dose is 60 mg/day

Dosing Schedule Options

• Three times daily (TID) dosing is traditional (5 mg TID initially)
• Twice daily (BID) dosing (7.5 mg BID) may be considered for improved adherence after initial titration period 1

Pharmacokinetic Considerations

Buspirone has several important pharmacokinetic properties that influence dosing:

• Rapid absorption with peak plasma concentration within 1 hour 2
• Short half-life of approximately 2-3 hours 2
• Low bioavailability (approximately 4%) due to extensive first-pass metabolism 2
• Metabolized to an active metabolite (1-pyrimidinylpiperazine or 1-PP) 2
• Linear pharmacokinetics over the dose range of 10-40 mg 2

Special Populations

Elderly Patients

• No dose adjustment needed based solely on age
• Pharmacokinetic studies show no significant differences in buspirone disposition between young and elderly subjects 3
• Start at the standard dose of 5 mg three times daily

Hepatic Impairment

• Use with caution in patients with hepatic impairment
• Significantly higher plasma concentrations (up to 15-fold) have been observed 2
• Consider starting at a lower dose (2.5 mg twice daily) and titrate slowly

Renal Impairment

• Moderate dose adjustment may be needed
• Plasma concentrations may be approximately 2-fold higher 2
• Consider starting at a lower dose (2.5 mg three times daily)

Safety and Tolerability

Buspirone has a favorable safety profile for long-term use:

• No evidence of tolerance, dependence, or withdrawal syndrome 4, 5
• Most common side effects include dizziness, headache, and nausea 1
• Minimal sedation compared to benzodiazepines 5
• No significant psychomotor impairment 5
• Long-term studies (up to 1 year) show no emergence of new or unexpected side effects 4

Drug Interactions

Important drug interactions to consider:

• Avoid concomitant use with MAO inhibitors
• Significant increases in buspirone levels with CYP3A4 inhibitors (verapamil, diltiazem, erythromycin, itraconazole) 2
• Significant decreases in buspirone levels with CYP3A4 inducers (rifampin) 2
• Adjust dose accordingly when these medications are started or stopped

Starting at the recommended dose of 5 mg three times daily and gradually titrating based on response and tolerability provides the optimal approach to buspirone therapy for most adult patients.