What is Buspar (Buspirone)?
Buspar (buspirone) is an FDA-approved anxiolytic medication specifically indicated for the management of generalized anxiety disorder (GAD) and short-term relief of anxiety symptoms. 1
Pharmacological Profile
Buspirone is an azaspirodecanedione compound that is chemically and pharmacologically distinct from benzodiazepines, barbiturates, and other sedative/anxiolytic drugs. 1
The drug functions primarily as a partial agonist at serotonin 5-HT1A receptors, with additional antagonist activity at dopamine D2 autoreceptors. 2
Unlike benzodiazepines, buspirone is "anxioselective"—it lacks hypnotic, anticonvulsant, and muscle relaxant properties, resulting in minimal sedation. 3
FDA-Approved Indication
Buspirone is indicated for generalized anxiety disorder, particularly in patients with persistent anxiety lasting at least 1 month, manifesting as motor tension, autonomic hyperactivity, apprehensive expectation, or hypervigilance. 1
The drug has demonstrated efficacy in controlled trials of outpatients with GAD, including those with coexisting mild depressive symptoms. 1
Efficacy beyond 3-4 weeks has not been established in controlled trials, though one study showed safe use for up to 1 year. 1
Critical Clinical Caveat: Delayed Onset
Buspirone requires 2-4 weeks for full anxiolytic effect, making it unsuitable for patients requiring immediate symptom relief. 4
This delayed onset distinguishes it from benzodiazepines and requires patient counseling to maintain compliance during the lag period. 5, 3
Off-Label Uses
The American College of Physicians suggests buspirone as an augmentation strategy for SSRI treatment in major depressive disorder, though it is less effective than bupropion and has higher discontinuation rates due to adverse events. 4
Buspirone may be useful for mild to moderate agitation in elderly patients with Alzheimer's disease/dementia at 5 mg twice daily (maximum 20 mg three times daily), though 2-4 weeks may be needed for effect. 4
The National Comprehensive Cancer Network considers buspirone for hypoactive sexual desire disorder in premenopausal cancer survivors, though data are limited. 4
Safety Profile
Buspirone does not impair psychomotor or cognitive function, has no additive effects with alcohol, and lacks abuse, dependence, and withdrawal potential. 3, 6
The most common adverse effects are headaches, dizziness, nervousness, and lightheadedness, occurring at low frequency. 7
The drug is safe even at very high doses and does not potentiate sedative-hypnotic drugs. 6
Dosing Characteristics
Buspirone is available in 5 mg, 7.5 mg, 10 mg, 15 mg, and 30 mg functionally-scored tablets allowing flexible dosing. 1
The drug has rapid absorption but low bioavailability (3.9%) with a short elimination half-life of 2.1 hours, metabolizing to an active metabolite (1-PP) with a 6.1-hour half-life. 7