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Sodium oxybate oral

Updated 2 Feb 2023 | Hypnotics


Oral solution containing sodium oxybate.

Drugs List

  • sodium oxybate 500mg/ml oral solution sugar-free
  • XYREM 500mg/ml oral solution
  • Therapeutic Indications


    Cataplexy associated with narcolepsy


    Each dose of sodium oxybate should be diluted with 60ml water prior to ingestion.

    Food significantly reduces the bioavailability of sodium oxybate, and so patients should eat several hours (at least 2 to 3) before taking the first dose of sodium oxybate at bedtime. The same timing of dosing should always be observed in relation to meals.

    Doses should be administered upon getting into bed and again between 2.5 to 4 hours later. It is recommended that both doses are made up at the same time.


    The recommended starting dose is 4.5g/day administered in two divided equal doses of 2.25g, the second dose separated by at least 2.5 to 4 hours from the first.

    The dose may be titrated up to a maximum of 9g/day in two divided doses based on efficacy and tolerability, by adjusting the dose up or down by increments of 1.5g/day. A minimum of one to two weeks is recommended between dosage increments.

    Single doses of 4.5g should not be administered unless the patient has been previously titrated to that dose level.


    Children aged 7 years and weighing more than 15kg
    Titration regimen
    More than or equal to 45kg: less than or equal to 1.5g per day per week. Recommended maximum total daily dose: 0.2g/kg/day.
    30kg to less than 45kg: less than or equal to 1g per day per week. Recommended maximum total daily dose: 0.2g/kg/day.
    20kg to less than 30kg: less than or equal to 1g per day per week. Recommended maximum total daily dose: 0.2g/kg/day.
    15kg to less than 20kg: less than or equal to 0.5g per day per week. Recommended maximum total daily dose: 9g/day.

    Initial dose regime
    More than or equal to 45kg: less than or equal to 4.5g per day, in two divided doses at bedtime and 2.5 to 4 hours later.
    30kg to less than 45kg: less than or equal to 3g per day, in two divided doses at bedtime and 2.5 to 4 hours later.
    20kg to less than 30kg: less than or equal to 2g per day, in two divided doses at bedtime and 2.5 to 4 hours later.
    15kg to less than 20kg: less than or equal to 1g per day, in two divided doses at bedtime and 2.5 to 4 hours later.

    Maximum daily dose for children weighing less than 45kg: 0.2g per kg per day.
    Maximum daily dose for children weighing 45kg or more: 9g per day.

    If the patient sleeps longer than 8 hours per night, sodium oxybate may be given after bedtime, while the child is in bed, in two equally divided doses 2.5 to 4 hours apart.

    It is recommended to leave one to two weeks between increments. Body weight should be checked at regular intervals to ensure appropriate dosage is given to children.

    Patients with Hepatic Impairment

    The starting dose should be halved in patients with hepatic impairment, and the response to dose increments monitored closely.

    Additional Dosage Information

    If the patient stops medication for more than 14 consecutive days, titration should be restarted from the lowest dose.

    The manufacturer suggests if sodium oxybate and sodium valproate are used concomitantly, the sodium oxybate dose should be decreased by 20%. The suggested starting dose for sodium oxybate, when used concomitantly with sodium valproate, is 3.6g per day administered in two equal divided doses of approximately 1.8g. If concomitant use is warranted, patient response and tolerability should be monitored and dose adjusted accordingly.


    Children under 7 years
    Children weighing less than 15kg
    Severe depression
    Succinic semialdehyde dehydrogenase deficiency

    Precautions and Warnings

    Obese patients with a BMI greater than 40kg/m2
    Restricted sodium intake
    Suicidal ideation
    Cardiac failure
    Epileptic disorder
    Hepatic impairment
    History of alcohol abuse
    History of depression
    History of drug misuse
    History of seizures
    Renal impairment
    Respiratory impairment
    Sleep apnoea

    Reduce dose in patients with hepatic impairment
    Sodium content of formulation may be significant
    Advise patient not to drive or operate machinery for at least 6 hours
    Treatment to be initiated and supervised by a specialist
    Must be diluted before use; see product information
    Be vigilant for medicines diversion
    Investigate patients presenting with faecal or urinary incontinence
    May cause respiratory depression
    Monitor and discontinue if appropriate if psychiatric or CNS problems occur
    Monitor for impaired motor &/or cognitive function especially in elderly
    Monitor for mental changes, suicidal depression and antisocial behaviour
    Monitor patient for signs and symptoms of respiratory depression
    Monitor patient for weight loss
    Monitor patients with a history of alcoholism and drug abuse
    Monitor patients with a history of depression and/or suicide attempts
    Monitor patients with BMI of or greater than 40kg/m2 for sleep apnoea
    Potential for drug abuse
    Advise patient/carer seek urgent medical advice if thought disorders occurs
    Advise patients/carers to seek medical advice if changes in behaviour/mood
    May cause dependence
    May increase risk of seizure
    Patient should be made aware of possible adverse effects on mood/behaviour
    Potential for withdrawal symptoms
    Advise patient to avoid alcohol during treatment
    Advise that effects are potentiated by CNS depressants (including alcohol)
    Patients with renal impairment should reduce their sodium intake

    Prescribers should be aware that sleep apnoea occurs in up to 50% of patients with narcolepsy. Patients should be assessed for sleep apnoea before treatment begins.

    Paediatric patients should have their breath monitored after administration for two hours to assess abnormality in breathing, if abnormal breath is observed, seek medical support and do not administer the second dose. Do not administer if the patient/caregiver is unable to provide careful monitoring.

    Confusion, behavioural disturbances and thought disorders, including thoughts of committing violent acts to self and/or others, in patients treated with sodium oxybate require careful and immediate evaluation.

    The emergence of depression during treatment requires immediate evaluation. Monitor patients with a history of depression and/or suicidal behaviour.

    Episodes of sleepwalking should be fully evaluated and appropriate interventions considered, due to the risk of injury or self harm.

    Cataplexy may return at a higher frequency upon discontinuation, or other withdrawal symptoms may occur.

    The reduction of sodium intake should be carefully considered in the management of patients with heart failure, hypertension or compromised renal function.

    Pregnancy and Lactation


    Sodium oxybate is contraindicated in pregnancy.

    The manufacturer does not recommend the use of sodium oxybate during pregnancy. There are limited data on use in human pregnancy, but data from a limited number of exposures in the first trimester indicate a possible increased risk of spontaneous abortions. Limited data indicates no malformative or foeto/neonatal toxicity from exposure in the second and third trimesters. Animal studies have not shown evidence of teratogenicity, but embryolethality was seen in both rat and rabbit studies.


    Sodium oxybate is contraindicated in breastfeeding.

    The manufacturer does not recommend the use of sodium oxybate in breastfeeding women. Changes in sleep patterns have been observed in breast fed infants, which may correspond with the effects of sodium oxybate treatment on the nervous system. Briggs (2015) suggest that waiting 5 hours after the last dose to just before the next dose breastfeeding is acceptable as no clinically significant exposure to the infant is expected due to sodium oxybates rapid rate of metabolism and short half.


    Patients should be advised that sodium oxybate has a major effect on the ability to drive and operate machinery. Patients should not undertake activities requiring mental alertness for at least 6 hours after administration. When treatment is initiated, patients should observe extreme caution until they know whether this product has any carry over effects the next day.

    Patients should be advised to avoid alcohol during treatment.

    Advise patient to discard any remaining solution 40 days after first opening.

    Side Effects

    Abdominal pain
    Abnormal thinking
    Attention disturbances
    Back pain
    Blurred vision
    Decreased appetite
    Dream abnormalities
    Faecal incontinence
    Feeling drunk
    Hypersensitivity reactions
    Increased appetite
    Increased blood pressure
    Loss of balance
    Loss of consciousness (transient)
    Muscle cramps
    Muscle spasm
    Nasal congestion
    Panic attack
    Peripheral oedema
    Respiratory depression
    Restless legs
    Sleep apnoea
    Sleep disturbances
    Sleep paralysis
    Sleep walking
    Suicidal tendencies
    Urinary incontinence
    Urinary urgency
    Violent behaviour
    Weight loss


    It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.

    The following number will direct the caller to the relevant local centre (0844) 892 0111

    Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( ) or if this is unavailable at the backup site ( ).

    Further Information

    Last Full Review Date: January 2015

    Reference Sources

    Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk, 9th edition (2011) ed. Briggs, G., Freeman, R. and Yaffe, S. Lippincott Williams & Wilkins, Philadelphia.

    Summary of Product Characteristics: Xyrem 500mg/ml oral solution. UCB Pharma Ltd. Revised November 2021.

    NICE Evidence Services Available at: Last accessed: 10 August 2021

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