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.

Precautions

It is very important that your doctor check your or your child's progress at regular visits to make sure the medicine is working properly and to check for any unwanted effects.

Do not use this medicine if you are also taking another sedative or hypnotic medicine (eg, Ambien®, Phenergan®, Seconal®). Also, do not drink alcohol while you are using this medicine. Doing so may increase the risk for serious unwanted effects.

It is against the law and dangerous for anyone else to use your medicine. Keep your unused medicine in a safe and secure place. People who are addicted to drugs might want to steal this medicine.

Check with your doctor before using this medicine with alcohol or other medicines that affect the central nervous system (CNS). The use of alcohol or other medicines that affect the CNS with Xywav® may worsen the side effects of this medicine, such as dizziness, poor concentration, drowsiness, unusual dreams, and trouble with sleeping. Some examples of medicines that affect the CNS are antihistamines or medicine for allergies or colds, sedatives, tranquilizers, or sleeping medicines, medicine for depression, medicine for anxiety, prescription pain medicine or narcotics, medicine for attention deficit and hyperactivity disorder, medicine for seizures or barbiturates, muscle relaxants, or anesthetics, including some dental anesthetics.

This medicine may make you dizzy, drowsy, or less alert than you are normally. Do not drive or do anything else that could be dangerous for at least 6 hours after taking this medicine.

Do not use more of this medicine or take it more often than your doctor tells you to. This can be life-threatening. Symptoms of an overdose include: extreme dizziness or weakness, slow heartbeat or breathing, seizures, trouble breathing, or cold, clammy skin. Call your doctor right away if you notice these symptoms.

This medicine may cause some people to be agitated, irritable, or display other abnormal behaviors. It may also cause some people to have suicidal thoughts and tendencies or to become more depressed. Make sure the doctor knows if you have trouble sleeping, get upset easily, have a big increase in energy, or start to act reckless. Also tell the doctor if you have sudden or strong feelings, such as feeling nervous, angry, restless, violent, or scared. If you or your caregiver notice any of these side effects, tell your doctor right away.

This medicine may cause unusual behavior while you are sleeping. Other people living in your house should monitor you for the possibility of sleep-related problems, including sleepwalking, sleep talking, sleep eating, or bedwetting. Tell your doctor if any of these occur.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or non-prescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

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:

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:

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]

See also:

Frequently asked questions

• Xywav vs Xyrem: What's the difference between them?
• 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