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Sodium Oxybate Dosage

Medically reviewed on April 12, 2018.

Applies to the following strengths: 500 mg/mL

Usual Adult Dose for Narcolepsy

Initial dose: 4.5 grams orally per night administered in two equal, divided doses of 2.25 g at bedtime and 2.25 g administered 2.5 to 4 hours later.
Maintenance dose: Increase the dose by 1.5 g orally per night at weekly intervals (additional 0.75 g at bedtime and 0.75 g administered 2.5 to 4 hours later) to the dose range of 6 g to 9 g per night.
Maximum dose: 9 g orally per night

Uses: Treatment of cataplexy in narcolepsy and excessive daytime sleepiness (EDS) in narcolepsy

Renal Dose Adjustments

Data not available

Liver Dose Adjustments

Initial dose: 2.25 g orally per night administered in two equal, divided doses of approximately 1.13 g at bedtime and approximately 1.13 g administered 2.5 to 4 hours later.

Dose Adjustments

Co-administration of Divalproex Sodium: For patients already stabilized on sodium oxybate, the addition of divalproex sodium should be accompanied by an initial reduction in the nightly dose of sodium oxybate by at least 20%. For patients already taking divalproex sodium, prescribers should use a lower starting sodium oxybate dose. Additionally, prescribers should monitor patient response and adjust dose as needed.


US REMS: The US FDA requires a Risk Evaluation and Mitigation Strategy (REMS) for this drug. It includes a medication guide, elements to assure safe use, and an implementation system. For additional information:

-Respiratory depression can occur with use.
-Sodium Oxybate is a Schedule III controlled substance and is the sodium salt of gamma hydroxybutyrate (GHB), a Schedule I controlled substance. Abuse or misuse of illicit GHB is associated with CNS adverse reactions, including seizure, respiratory depression, decreased consciousness, coma and death.
-Because of the risks of CNS depression, abuse, and misuse, sodium oxybate is available only through a restricted distribution program called the Xyrem Success Program(R) using a centralized pharmacy. Prescribers and patients must enroll in the program.

Safety and efficacy have not been established in patients younger than 18 years.

Consult WARNINGS section for additional precautions.

US Controlled Substance: Sodium Oxybate Schedule III; (GHB) Schedule I


Data not available

Other Comments

Administration advice:
-The first dose should be taken at least 2 hours after eating.
-Prepare both doses prior to bedtime. Prior to ingestion, each dose should be diluted with approximately ΒΌ cup (approximately 60 mL) of water in the empty vials provided.
-Patients should take both doses while in bed and lie down immediately after dosing.
-Patients should remain in bed following ingestion of the first and second doses, and should not take the second dose until 2.5 to 4 hours after the first dose.
-Patients may need to set an alarm to awaken for the second dose.

Storage requirements:
-Keep out of reach of children.

Patient advice:
-Patients should not drink alcohol or take other sedative hypnotics.
-Patients should remain in bed following ingestion of the first and second doses.
-Patients should not operate hazardous machinery, including automobiles or airplanes.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.