What is the recommended dosage of buspirone (anxiolytic medication) for adults?

Recommended Dosage of Buspirone for Adults

The recommended dosage of buspirone for adults starts at 5 mg twice daily, with a maximum dosage of 20 mg three times daily (60 mg total daily dose). 1

Initial Dosing and Titration

• Start with 5 mg twice daily 1
• Gradually increase the dose every 5-7 days as needed for symptom control 1
• Typical maintenance dosage ranges from 15-30 mg per day divided into multiple doses 2, 3
• Allow 2-4 weeks for full therapeutic effect to be observed 1

Maximum Dosage

• Maximum recommended dose is 20 mg three times daily (60 mg total daily) 1
• Most patients are successfully managed on daily doses ranging from 15 to 30 mg/day 3

Pharmacokinetic Considerations

• Buspirone has a short half-life of approximately 2.5 hours 4
• Absolute bioavailability is low (approximately 4%) 4
• Food increases the peak plasma concentration and bioavailability approximately 2-fold 4
• No accumulation occurs with multiple dosing 4

Special Populations

• In patients with hepatic impairment: Use lower doses as plasma concentrations can be 15-fold higher and half-life is doubled 4
• In patients with renal impairment: Consider dose reduction as plasma concentrations can be 2-fold higher 4
• In older or frail patients: Start at the lower end of the dosing range 1

Drug Interactions

• Significant increases in buspirone plasma concentrations occur with verapamil, diltiazem, erythromycin, and itraconazole 4
• Rifampin can decrease buspirone plasma concentrations by approximately 10-fold 4
• Monitor for drug interactions when combining with medications metabolized by cytochrome P450 enzymes 4

Clinical Pearls

• Buspirone is useful only for mild to moderate anxiety/agitation 1
• Unlike benzodiazepines, buspirone lacks hypnotic, anticonvulsant, and muscle relaxant properties 2
• There is typically a 1-2 week lag time before onset of anxiolytic effect 2
• Periodic reevaluation of the need for continued therapy is recommended, especially for treatment extending beyond several months 3
• Buspirone does not cause physiologic dependence or withdrawal symptoms when discontinued after long-term use 3
• Common side effects include dizziness, nervousness, and headaches 5

Monitoring

• Assess therapeutic response after 2-4 weeks of treatment 1
• If no improvement is seen after 4-6 weeks at maximum tolerated dose, consider alternative treatment 2
• For long-term therapy, periodically reassess the need for continued treatment 3