Recommended Dosage of Buspirone for Generalized Anxiety Disorder (GAD)
For treating generalized anxiety disorder (GAD), buspirone should be initiated at 5 mg twice daily with a maximum dosage of 20 mg three times daily (60 mg total daily dose). 1
Dosing Schedule and Titration
- Initial dosage should be 5 mg twice daily 1
- Dosage can be gradually increased using increments of the initial dose every 5-7 days until therapeutic benefits or significant side effects become apparent 1
- Maximum recommended dosage is 20 mg three times daily (60 mg total daily dose) 1
- A twice-daily dosing regimen (15 mg twice daily) is as effective as three times daily dosing (10 mg three times daily) and may offer greater convenience and possibly higher compliance 2, 3
Onset of Action and Duration of Treatment
- Buspirone may take 2-4 weeks to become effective, unlike benzodiazepines which have immediate effects 1
- A full therapeutic trial requires at least 4-8 weeks 1
- Patients should be informed about this delayed onset of action to manage expectations and improve adherence 4
Clinical Considerations
- Buspirone is most useful for patients with mild to moderate anxiety 1
- Unlike benzodiazepines, buspirone does not cause physical dependence, tolerance, or withdrawal symptoms 4, 5
- Buspirone has minimal sedative effects and does not impair psychomotor function 5
- Buspirone does not potentiate the effects of alcohol 5
Special Populations
- For elderly patients: Start at the lower end of the dosing range due to increased sensitivity to medication effects 6
- For patients with impaired hepatic or renal function: Buspirone administration to patients with severe hepatic or renal impairment is not recommended due to increased plasma levels and lengthened half-life 6
Adverse Effects
- Most common side effects include dizziness, headache, and nausea 3
- Other potential adverse effects include nervousness, lightheadedness, and gastrointestinal disturbances 5
- The incidence of adverse events is similar between twice-daily and three-times-daily dosing regimens, except for a higher incidence of palpitations with twice-daily dosing (5% vs 1%) 3
Drug Interactions
- Buspirone may interact with drugs that affect CYP3A4 enzyme system 6
- Coadministration with cimetidine increases maximum concentration (Cmax) by 40% and doubles the time to maximum concentration (Tmax) 6
- Buspirone should be discontinued at least 48 hours prior to undergoing urine collection for catecholamines to avoid false positive results for metanephrine 6
Clinical Pearls
- Buspirone is most helpful for patients who do not require immediate anxiety relief 4
- It is particularly appropriate for patients with chronic anxiety, anxious elderly patients, and those with mixed symptoms of anxiety and depression 4
- Buspirone is not recommended for routine treatment of panic disorder as studies have been inconclusive 4