Pharmacology · Other anxiolytics
Buspirone !
A non-sedating anxiety medicine that acts on serotonin 5-HT1A receptors. It causes no dependence, but does not work at once or on panic attacks.
Updated 2026-11-01
The figure shows buspirone itself bound to the human 5-HT1A receptor coupled to its Gi protein.
Mechanism of action
Buspirone binds serotonin 5-HT1A receptors with high affinity and dopamine D2 receptors moderately. How this relieves anxiety is not fully known. It has no affinity for the benzodiazepine site and does not change GABA binding, so it lacks anticonvulsant, muscle-relaxant and marked sedative effects.
- Binds serotonin 5-HT1A receptors
- Serotonin signalling adapts over weeks
- Anxiety slowly eases, without sedation
Pharmacokinetics
- Absorption
- Absorbed by mouth with extensive first-pass metabolism; food increases absorption, so it is taken the same way each time
- Metabolism
- Mainly by CYP3A4
- Half-life
- About 2 to 3 hours
Indications
- Anxiety disorders, mainly generalized anxiety disorder Generalized anxiety disorder →
Adverse effects
Common
- Dizziness and light-headedness
- Nausea
- Headache
- Nervousness and excitement
Contraindications
- Hypersensitivity to buspirone
- MAO inhibitors, or within 14 days of stopping one; linezolid or IV methylene blue
Key interactions
- MAO inhibitors
- High blood pressure and serotonin syndrome
- CYP3A4 inhibitors (diltiazem, verapamil, erythromycin, itraconazole, nefazodone) and grapefruit juice
- Higher buspirone levels
- Rifampin (CYP3A4 inducer)
- Lower buspirone levels
What is monitored
- Anxiety symptoms over the following weeks; the need for treatment is reviewed periodically
- Dizziness
Administration and safety
- Given by mouth, always with food or always without it
- Not a controlled substance
- A benzodiazepine is tapered gradually before switching; buspirone does not cover withdrawal
Nursing care
- Teach that relief builds over weeks and that it is not taken «as needed» for panic
- Ask about MAO inhibitors and other serotonergic drugs
- Teach to avoid large amounts of grapefruit juice
- Check for dizziness before walking
Pregnancy and breastfeeding
Human data are limited; the benefit is weighed against unknown risk.
Test yourself
Think of the answer, then tap the question to see it.
Can buspirone be used for an acute panic attack?
No; its anxiolytic effect builds over weeks.
Why must a long-term benzodiazepine user be tapered before starting buspirone?
Buspirone has no cross-tolerance and will not block benzodiazepine withdrawal.
Which drink raises buspirone levels?
Grapefruit juice (CYP3A4 inhibition).
Related drugs
Related conditions
← Back to the class: Other anxiolytics
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: DailyMed - BUSPIRONE HYDROCHLORIDE tablet (DailyMed (U.S. National Library of Medicine), 2026); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026); 8FYX: Buspirone-bound serotonin 1A (5-HT1A) receptor-Gi1 protein complex (RCSB Protein Data Bank, 2024).
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Representative model, for educational purposes only.