Buspirone
BUSPAR
Pronunciation: byoo-SPYE-roen
“Bus spear”
What it is5-HT1A partial agonist with 5-HT2A and D2 antagonism; generalized anxiety disorder.
Why this oneRelieves chronic anxiety without dependence, respiratory depression or meaningful cognitive slowing.
What limits itDoes not work as needed; delayed onset must be explained. CYP3A4 inhibitors and grapefruit raise exposure.
Pearls
- Used mainly as an adjunct, though labeled as monotherapy.
- GAD efficacy similar to benzodiazepines, below venlafaxine.
- Dizziness, nausea and headache are the usual complaints.
- Label advises avoiding during breastfeeding.
FDA-approved for
- GAD (1986)
Off-label
- antidepressant augmentation
- SSRI-induced bruxism
Principal riskLittle; its main failure is being expected to work acutely
Classes and tags
Clinical profile
Legacy pregnancy categoryB
Defining liabilitySedation, falls, dependence and additive respiratory depression with opioids or other CNS depressants.
FDA label
Read the full label on DailyMed ↗
NO BOXED WARNINGS
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Anxiety disorders / short-term relief of anxiety | Adults | 15 mg/day (7.5 mg BID) | 20–30 mg/day divided | 60 mg/day |
Titration May increase 5 mg/day every 2–3 days
Renal Undefined
Hepatic Undefined
Instructions
- Take consistently with regard to food (always with or always without)
- Reduce dose with potent CYP3A4 inhibitors
- Allow at least 14 days between an MAOI antidepressant and buspirone in either direction
Available strengths
- tab 5, 7.5, 10, 15, 30 mg
Contraindications
- MAOIs (concurrently or within 14 days) due to risk of serotonin syndrome
Cautions
- Risk of serotonin syndrome cited with concomitant serotonergic drugs, MAOIs, linezolid, or IV methylene blue (per label)
Adverse reactions
- Dizziness
- Nausea
- Headache
- Nervousness
- Lightheadedness
- Excitement
- Drowsiness, dry mouth
Pregnancy Undefined
Lactation Undefined
Cost
Generic entry2001
Active metabolites
Open Buspirone in the interactive console ↗
Memory aids: interaction avatars
Open Buspirone in the interactive console ↗
Self-check
- Does buspirone work as needed?
No; onset is delayed. - What fruit product raises buspirone exposure?
Grapefruit.