Brexanolone
Neurosteroid antidepressants
Neurosteroid antidepressants
Allopregnanolone given as a 60-hour IV infusion for postpartum depression. It boosts GABA-A receptors and can cause sudden loss of consciousness.
Also called: Allopregnanolone
Quick facts
- Group
- Neurosteroid antidepressants
- Target
- GABA-A receptor (positive allosteric modulator)
- Used for
- Postpartum depression in adults
- Key effects
- Sleepiness and fatigue · Dry mouth
- Monitor
- Mood and suicidal thoughts · Kidney function
- ATC
- N06AX29
No doses: the clinician sets them by the current guideline.
Mechanism of action
The figure shows allopregnanolone (the same molecule as brexanolone) bound to the human alpha1-beta2-gamma2 GABA-A receptor together with GABA.
Brexanolone is a formulation of allopregnanolone, a natural neurosteroid. It binds GABA-A receptors at a site distinct from GABA and benzodiazepines and increases the chloride current that GABA opens, so neurons become harder to excite. Restoring this neurosteroid signal may relieve postpartum depression; the same action produces sedation.
- Brexanolone binds a neurosteroid site on GABA-A receptors
- GABA opens more chloride current: neurons are calmer
- May restore a reduced neurosteroid signal
- Same action causes sedation and possible loss of consciousness
Indications
- Postpartum depression in adults Perinatal depression and postpartum psychosis →
Adverse effects
Common
- Sleepiness and fatigue
- Dizziness or a spinning sensation
- Dry mouth, mouth or throat pain, heartburn
- Flushing and hot flushes
Contraindications
- End-stage renal disease (the solubilising agent can accumulate)
Key interactions
- Opioids, benzodiazepines, other sedatives, antidepressants and alcohol
- Added sedation and risk of loss of consciousness
What is monitored
- Level of sedation at regular intervals while awake during the infusion
- Mood and suicidal thoughts
- Kidney function
Administration and safety
- Given only in a certified health facility under a restricted distribution programme
- The infusion is paused or stopped if excessive sedation occurs
- No driving or operating machinery until the sleepiness has passed
Pregnancy and breastfeeding
It is used after childbirth; data on breastfeeding are limited, so the decision is made with the treating team.
Nursing care
- Checks for sleepiness every few hours while the patient is awake and reports excessive sedation at once
- Makes sure another adult cares for the baby during and after the infusion
- Asks about suicidal thoughts and changes in mood
- Reviews other sedating medicines and alcohol use
Pharmacokinetics
- Absorption
- Continuous intravenous infusion over about 60 hours (2.5 days)
- Metabolism
- Keto-reduction, glucuronidation and sulfation, not by CYP enzymes as the main route
- Half-life
- About 9 hours after the infusion ends
Test yourself
Think of the answer, then tap the question to see it.
What natural molecule is brexanolone, and where does it act?
Allopregnanolone; it is a positive allosteric modulator of GABA-A receptors.
Why is brexanolone given only in a monitored facility?
It can cause excessive sedation and sudden loss of consciousness.
Why is it avoided in end-stage renal disease?
The solubilising agent in the infusion can accumulate.
Connections
← Back to the class: Neurosteroid antidepressants
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: Brexanolone Injection: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2026); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026).
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Representative model, for educational purposes only.