Azapirone — Non-benzodiazepine Anxiolytic

Buspirone

Brand names: Buspar

Buspirone is a non-benzodiazepine anxiolytic used in the management of generalised anxiety disorder, often where avoidance of benzodiazepine-related sedation and dependence is desirable.

Dosing — being independently re-sourced

ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.

US labelling (FDA)

Reference — US labelling, may differ from UK

DOSAGE AND ADMINISTRATION The recommended initial dose is 15 mg daily (7.5 mg b.i.d.). To achieve an optimal therapeutic response, at intervals of 2 to 3 days the dosage may be increased 5 mg per day, as needed. The maximum daily dosage should not exceed 60 mg per day. In clinical trials allowing dose titration, divided doses of 20 to 30 mg per day were commonly employed. The bioavailability of buspirone is increased when given with food as compared to the fasted state (see CLINICAL PHARMACOLOGY ). Consequently, patients should take buspirone in a consistent manner with regard to the timing of dosing; either always with or always without food. When buspirone is to be given with a potent …

Source: US FDA prescribing information (openFDA / DailyMed), label dated 2019-05-03. Accessed 2026-06-12. US dosing and indications can differ from UK practice — use UK sources for prescribing decisions.

Clinical monograph

How it works

It is a partial agonist at presynaptic and postsynaptic 5-HT1A serotonin receptors, modulating serotonergic neurotransmission. Unlike benzodiazepines it has no direct action at the GABA receptor and lacks sedative, anticonvulsant and muscle-relaxant properties.

Prescribing in practice

Its anxiolytic effect develops gradually over one to two weeks, so it is unsuitable for acute anxiety or 'as-needed' relief and should be taken regularly; it does not produce the dependence associated with benzodiazepines.
Common effects include dizziness, nausea, headache and light-headedness.
It is metabolised by CYP3A4, so concentrations are raised by CYP3A4 inhibitors (avoid grapefruit juice) and there is a risk of serotonin syndrome if combined with MAOIs — see the SPC for interaction detail.

Monitoring

Review anxiety symptoms and tolerability after the first couple of weeks, since onset is delayed. Be alert for features of serotonin syndrome when other serotonergic drugs are co-prescribed, and reassess interacting medicines and dose where CYP3A4 inhibitors or inducers are involved.

Counselling the patient

Take this medicine regularly every day — it is not a 'when needed' treatment and can take one to two weeks before you notice the benefit.
Avoid grapefruit and grapefruit juice, which can raise the amount of medicine in your body.
Tell your prescriber about all other medicines you take, and report agitation, sweating, shivering or a racing heartbeat.

Evidence & guidelines

A recognised non-benzodiazepine option for generalised anxiety disorder in UK practice (NICE), valued for its lack of dependence compared with benzodiazepines.

Reference: NICE CG22 (Anxiety); NICE NG106 (GAD); Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways