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Calcium oxybate / magnesium oxybate / potassium oxybate / sodium oxybate Side Effects

For the Consumer

Applies to calcium oxybate/magnesium oxybate/potassium oxybate/sodium oxybate: oral liquid


This medicine can cause severe drowsiness and can slow or stop your breathing, even at regular doses or if you are also taking stimulant medicines.

Fatal side effects can occur if you take Xywav with: alcohol, other sleep medicines, or other drugs that cause drowsiness or slow your breathing.

Misuse of this medicine can cause breathing problems, seizure, loss of consciousness, or death. Keep the medication in a place where others cannot get to it.

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have:

  • weak or shallow breathing, breathing that stops for short periods of time;

  • severe drowsiness, feeling light-headed;

  • sleepwalking (may result in an injury), waking and confused behavior at night;

  • a seizure;

  • depression, anxiety, unusual or unpleasant thoughts;

  • feelings of low self-worth, loss of interest in things you once enjoyed;

  • confusion, paranoia, hallucinations (seeing or hearing things);

  • increased tiredness, trouble concentrating; or

  • suicidal thoughts or actions.

Common side effects may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects.

For Healthcare Professionals

Applies to calcium oxybate / magnesium oxybate / potassium oxybate / sodium oxybate: oral liquid


The most commonly reported side effects included headache, nausea, dizziness, and decreased appetite.[Ref]

Nervous system

Very common (10% or more): Headache (up to 20%)

Common (1% to 10%): Dizziness, paresthesia, somnolence, tremor

Frequency not reported: Attention disturbance, cataplexy, central nervous system depression, sleep paralysis

Postmarketing reports: Memory impairment[Ref]


Very common (10% or more): Nausea (up to 17%), vomiting (up to 16%)

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


Very common (10% or more): Enuresis (up to 18%)

Common (1% to 10%): Anxiety, depressed mood, depression, irritability, parasomnia

Frequency not reported: Abnormal dreams, abnormal sleep-related event, abuse, affect lability, agitation, disorientation, other behavioral adverse reactions, other psychiatric adverse reactions, panic attack, rapid eye movements sleep abnormal, sleep-disordered breathing, sleep-related eating disorder, sleep talking, sleep terror, somnambulism, suicidal ideation, suicidality, tactile hallucination, tension[Ref]


Very common (10% or more): Decreased appetite (up to 12%)

Common (1% to 10%): Decreased appetite

Postmarketing reports: Fluid retention[Ref]


Common (1% to 10%): Fatigue

Frequency not reported: Asthenia, feeling drunk, misuse, pain

Postmarketing reports: Fall, hangover[Ref]


Common (1% to 10%): Muscle spasms

Frequency not reported: Extremity pain

Postmarketing reports: Arthralgia[Ref]


Common (1% to 10%): Hyperhidrosis

Frequency not reported: Night sweats[Ref]


Frequency not reported: Respiratory depression, sleep apnea syndrome[Ref]


Postmarketing reports: Hypertension[Ref]


Postmarketing reports: Hypersensitivity[Ref]


Postmarketing reports: Blurred vision[Ref]


Postmarketing reports: Nocturia[Ref]


1. "Product Information. Xywav (calcium/magnesium/potass/sodium oxybates)." Jazz Pharmaceuticals, Palo Alto, CA.

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.