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Xyrem Side Effects

Generic name: sodium oxybate

Medically reviewed by Philip Thornton, DipPharm. Last updated on May 4, 2022.

Note: This document contains side effect information about sodium oxybate. Some of the dosage forms listed on this page may not apply to the brand name Xyrem.


Common side effects of Xyrem include: dizziness and nausea. See below for a comprehensive list of adverse effects.

For the Consumer

Applies to sodium oxybate: oral solution


Oral route (Solution)

Central Nervous System (CNS) Depression and Abuse and MisuseCentral Nervous System DepressionSodium oxybate is a CNS depressant, and respiratory depression can occur with sodium oxybate use.Abuse and MisuseSodium oxybate is the sodium salt of gamma-hydroxybutyrate (GHB). Abuse or misuse of illicit GHB is associated with CNS adverse reactions, including seizure, respiratory depression, decreased consciousness, coma, and death.Sodium oxybate is available only through a restricted program called the Xywav and Xyrem REMS.

Side effects requiring immediate medical attention

Along with its needed effects, sodium oxybate (the active ingredient contained in Xyrem) 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 sodium oxybate:

More common

Less common

  • Burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
  • changes in behavior
  • choking or gasping sounds
  • daytime sleepiness or tiredness
  • headache
  • lack of appetite
  • loud or frequent snoring
  • rapid weight gain
  • seeing, hearing, or feeling things that are not there
  • thoughts of killing oneself
  • trouble sleeping
  • unusual weight gain or loss
  • waking to urinate at night

Incidence not known

  • Being forgetful
  • blurred vision
  • decrease in the amount of urine
  • dizziness
  • fever
  • hives, itching, skin rash
  • hoarseness
  • increase urge to urinate at 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
  • tightness in the chest
  • trouble breathing or swallowing
  • weight gain

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

Symptoms of overdose

  • Agitation
  • bluish lips or skin, not breathing
  • chest pain or discomfort
  • clumsiness
  • confusional, agitated combative state
  • drowsiness
  • generalized slowing of mental and physical activity
  • inability to hold bowel movement or urine
  • increased sweating
  • lightheadedness, dizziness, or fainting
  • loss of consciousness
  • muscle aches or weakness
  • seizures
  • shakiness and unsteady walk
  • shivering
  • slow or irregular heartbeat
  • trembling or other problems with muscle control or coordination
  • unusual tiredness or weakness
  • weak or feeble pulse

Side effects not requiring immediate medical attention

Some side effects of 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

  • Diarrhea
  • difficulty passing urine (dribbling)
  • increased frequency, urgency, or burning on urination
  • increased sweating
  • nausea
  • vomiting

Less common

  • Dry mouth

Incidence not known

  • Difficulty with moving

For Healthcare Professionals

Applies to sodium oxybate: oral liquid


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

Nervous system

Very common (10% or more): Dizziness (up to 20%), headache (up to 20%)

Common (1% to 10%): Balance disorder, cataplexy, disturbance in attention, dysgeusia, hypoesthesia, paresthesia, sedation, sleep paralysis, somnolence, tremor, vertigo

Uncommon (0.1% to 1%): Amnesia, myoclonus, restless legs syndrome

Frequency not reported: Central nervous system depression, convulsion, dyskinesia, loss of consciousness

Postmarketing reports: Memory impairment[Ref]

Disturbance in attention and paresthesia were dose-related, with the side effects occurring more frequently at 9 g/day.[Ref]


Very common (10% or more): Nausea (up to 20%), vomiting (up to 11%)

Common (1% to 10%): Abdominal pain upper, diarrhea, dry mouth, upper abdominal pain

Uncommon (0.1% to 1%): Fecal incontinence[Ref]

Nausea and vomiting were dose-related, with the side effects occurring more frequently at 9 g/day.

The frequency of nausea was higher in women than in men.[Ref]


Very common (10% or more): Enuresis (up to 19%)

Common (1% to 10%): Abnormal dreams, acute psychosis, anxiety, confusional state, depression, disorientation, enuresis nocturna, insomnia, irritability, middle insomnia, nervousness, nightmares, sleep disorder, sleepwalking, suicidal ideation

Uncommon (0.1% to 1%): Abnormal thinking, agitation, hallucination, initial insomnia, paranoia, psychosis, suicide attempt

Frequency not reported: Abuse, affect lability, aggression, bipolar disorder, bruxism, delusion, euphoric mood, homicidal ideation, increased libido, mania, other behavioral adverse reactions, other psychiatric adverse reactions, parasomnias, psychotic disorders, panic attack, sleep-disordered breathing, sleep-related eating disorder, suicidality, tactile hallucination

Postmarketing reports: Abnormal behavior, mood alteration[Ref]

Disorientation, enuresis, irritability, and sleepwalking were dose-related, with the side effects occurring more frequently at 9 g/day.[Ref]


Very common (10% or more): Weight decreased (up to 13%)

Common (1% to 10%): Anorexia, decreased appetite

Postmarketing reports: Dehydration, fluid retention, increased appetite[Ref]


Common (1% to 10%): Dyspnea, nasal congestion, nasopharyngitis, sinusitis, snoring

Frequency not reported: Choking sensation, respiratory depression, sleep apnea/sleep apnea syndrome[Ref]


Feeling drunk was dose-related, with the side effect occurring more frequently at 9 g/day.[Ref]

Common (1% to 10%): Asthenia, fall, fatigue, feeling drunk, pain

Frequency not reported: Misuse, tinnitus

Postmarketing reports: Hangover[Ref]


Common (1% to 10%): Blood pressure increased, hypertension, palpitations, peripheral edema[Ref]


Common (1% to 10%): Arthralgia, back pain, muscle spasms, pain in extremity[Ref]


Common (1% to 10%): Hyperhidrosis, rash

Frequency not reported: Seborrhea, urticaria[Ref]


Common (1% to 10%): Urinary incontinence

Frequency not reported: Micturition urgency, nocturia, pollakiuria[Ref]


Common (1% to 10%): Blurred vision[Ref]


Uncommon (0.1% to 1%): Hypersensitivity

Frequency not reported: Angioedema[Ref]

Frequently asked questions


1. "Product Information. Xyrem (sodium oxybate)." Orphan Medical (2002):

2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0

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.