Xywav Side Effects

Generic name: calcium oxybate / magnesium oxybate / potassium oxybate / sodium oxybate

Medically reviewed by Philip Thornton, DipPharm. Last updated on Apr 7, 2025.

Note: This document provides detailed information about Xywav Side Effects associated with calcium oxybate / magnesium oxybate / potassium oxybate / sodium oxybate. Some dosage forms listed on this page may not apply specifically to the brand name Xywav.

Applies to calcium oxybate / magnesium oxybate / potassium oxybate / sodium oxybate: oral solution.

Important warnings This medicine can cause some serious health issues

Oral route (solution)

Central Nervous System Depression. Calcium oxybate/magnesium oxybate/potassium oxybate/sodium oxybate is a CNS depressant.

Clinically significant respiratory depression and obtundation may occur in patients treated with calcium oxybate / magnesium oxybate / potassium oxybate / sodium oxybate at recommended doses.

Many patients who received calcium oxybate / magnesium oxybate / potassium oxybate / sodium oxybate during clinical trials in narcolepsy and idiopathic hypersomnia were receiving central nervous system stimulantsAbuse and Misuse. The active moiety of calcium oxybate / magnesium oxybate / potassium oxybate / sodium oxybate is oxybate or gamma hydroxybutyrate (GHB).

Abuse or misuse of illicit GHB, either alone or in combination with other CNS depressants, is associated with CNS adverse reactions, including seizure, respiratory depression, decreases in the level of consciousness, coma, and death.Because of the risks of CNS depression and abuse and misuse, calcium oxybate / magnesium oxybate / potassium oxybate / sodium oxybate is available only through a restricted program under a Risk Evaluation and Mitigation Strategy (REMS) called the Xywav and Xyrem REMS.

Serious side effects of Xywav

Along with its needed effects, calcium oxybate / magnesium oxybate / potassium oxybate / sodium oxybate 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 immediately if any of the following side effects occur while taking calcium oxybate / magnesium oxybate / potassium oxybate / sodium oxybate:

More common side effects

• bedwetting
• sleepiness or unusual drowsiness
• sleepwalking

Less common side effects

• anxiety
• burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
• confusion about identity, place, and time
• discouragement
• feeling sad or empty
• irritability
• lack of appetite
• loss of interest or pleasure
• pain in the arm or leg
• seeing, feeling, or hearing things that are not there
• sleep paralysis
• thoughts of killing oneself
• tremor
• trouble breathing
• trouble concentrating
• trouble sleeping
• unusual tiredness or weakness

Incidence not known

• being forgetful
• blurred vision
• chest tightness
• decrease in the amount of urine
• dizziness
• falls
• fever
• headache
• hives, itching, skin rash
• hoarseness
• increased urge to urinate during the night
• irritation
• joint pain, stiffness, or swelling
• nervousness
• noisy, rattling breathing
• pounding in the ears
• redness of the skin
• swelling of the face, fingers, hands, feet, or lower legs
• trouble swallowing
• waking to urinate at night
• weight gain

Get emergency help immediately if any of the following symptoms of overdose occur while taking calcium oxybate / magnesium oxybate / potassium oxybate / sodium oxybate:

Symptoms of overdose

• agitation
• chest pain or discomfort
• clumsiness
• drowsiness
• lightheadedness, dizziness, or fainting
• loss of consciousness
• loss of strength or energy
• low body temperature
• muscle pain or weakness
• seizures
• shakiness and unsteady walk
• shivering
• slow or irregular heartbeat
• unsteadiness, trembling, or other problems with muscle control or coordination
• unusual weak feeling
• weak or feeble pulse

Other side effects of Xywav

Some side effects of calcium oxybate / magnesium oxybate / potassium oxybate / sodium oxybate 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 side effects

• decreased weight
• diarrhea
• dry mouth
• increased sweating
• nausea
• vomiting

Less common side effects

• clenching, gnashing, or grinding teeth
• feeling drunk
• snoring

Incidence not known

• difficulty in moving

For healthcare professionals

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

General adverse events

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]

Gastrointestinal

• Very common (10% or more): Nausea (up to 17%), vomiting (up to 16%)
• Common (1% to 10%): Diarrhea, dry mouth^[Ref]

Psychiatric

• 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]

Metabolic

• Very common (10% or more): Decreased appetite (up to 12%)
• Common (1% to 10%): Decreased appetite
• Postmarketing reports: Fluid retention^[Ref]

Other

• Common (1% to 10%): Fatigue
• Frequency not reported: Asthenia, feeling drunk, misuse, pain
• Postmarketing reports: Fall, hangover^[Ref]

Musculoskeletal

• Common (1% to 10%): Muscle spasms
• Frequency not reported: Extremity pain
• Postmarketing reports: Arthralgia^[Ref]

Dermatologic

• Common (1% to 10%): Hyperhidrosis
• Frequency not reported: Night sweats^[Ref]

Respiratory

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

Cardiovascular

• Postmarketing reports: Hypertension^[Ref]

Hypersensitivity

• Postmarketing reports: Hypersensitivity^[Ref]

Ocular

• Postmarketing reports: Blurred vision^[Ref]

Genitourinary

• Postmarketing reports: Nocturia^[Ref]

Frequently asked questions

• What is the difference between Xywav vs Xyrem?
• How effective is Xywav for Idiopathic Hypersomnia?

Further information

Xywav side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer