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Brexanolone Side Effects

Medically reviewed by Last updated on Aug 19, 2023.

Applies to brexanolone: intravenous solution.


Intravenous route (Solution)

Warning: Excessive Sedation and Sudden Loss of ConsciousnessPatients are at risk of excessive sedation or sudden loss of consciousness during administration of brexanolone.Because of the risk of serious harm, patients must be monitored for excessive sedation and sudden loss of consciousness and have continuous pulse oximetry monitoring. Patients must be accompanied during interactions with their child(ren).Brexanolone is available only through a restricted program called the ZULRESSO REMS.

Serious side effects of Brexanolone

Along with its needed effects, brexanolone may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur while taking brexanolone:

More common

  • Dizziness or lightheadedness
  • drowsiness
  • fainting
  • feeling of constant movement of self or surroundings
  • relaxed and calm feeling
  • sensation of spinning
  • sleepiness or unusual drowsiness

Less common

  • Fast, pounding, or irregular heartbeat or pulse
  • loss of consciousness

Get emergency help immediately if any of the following symptoms of overdose occur while taking brexanolone:

Symptom of overdose

  • Prolonged drowsiness

Other side effects of Brexanolone

Some side effects of brexanolone may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

Less common

  • Acid or sour stomach
  • belching
  • diarrhea
  • feeling of warmth
  • heartburn
  • indigestion
  • mouth or throat pain
  • redness of the face, neck, arms, and occasionally, upper chest
  • stomach discomfort, upset, or pain

For Healthcare Professionals

Applies to brexanolone: intravenous solution.


The most commonly reported side effects included sedation, somnolence, dizziness, presyncope, and vertigo.[Ref]

Nervous system

Very common (10% or more): Sedation (up to 21%), somnolence (up to 21%), dizziness (up to 13%), presyncope (up to 13%), vertigo (up to 13%)

Common (1% to 10%): Loss of consciousness, syncope[Ref]


Dyspepsia was a dose-related side effect.[Ref]

Very common (10% or more): Dry mouth (up to 11%)

Common (1% to 10%): Diarrhea, dyspepsia[Ref]


Tachycardia was a dose-related side effect.[Ref]

Common (1% to 10%): Changes in blood pressure, flushing, hot flush, tachycardia[Ref]


Common (1% to 10%): Infusion site events, infusion site pain[Ref]


Common (1% to 10%): Fatigue, medication error (due to infusion pump malfunction)[Ref]


Common (1% to 10%): Oropharyngeal pain[Ref]

Frequently asked questions


1. Product Information. Zulresso (brexanolone). Sage Therapeutics, Inc. 2019.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.