calcium, magnesium, potassium, and sodium oxybates

Adjunctive therapy

Brands: Xywav

Last reviewed 2025-12-30

Reviewed by PsychMed Editorial Team.

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Quick answers

What is calcium, magnesium, potassium, and sodium oxybates?
Calcium, magnesium, potassium, and sodium oxybates (brand Xywav) is a nighttime medication indicated for Cataplexy or excessive daytime sleepiness (EDS) in patients 7 years of age and older with narcolepsy and for IH in adults (label).
What is Xywav?
Xywav is a brand name for calcium, magnesium, potassium, and sodium oxybates.
What is Xywav (calcium, magnesium, potassium, and sodium oxybates) used for?
Label indications include: Treatment of cataplexy or excessive daytime sleepiness (EDS) in patients 7 years of age and older with narcolepsy; treatment of idiopathic hypersomnia (IH) in adults; REMS-restricted (label).
What drug class is Xywav (calcium, magnesium, potassium, and sodium oxybates)?
Nighttime CNS depressant (oxybate/GHB; lower-sodium oxybate salts) indicated for cataplexy or excessive daytime sleepiness in narcolepsy (patients 7+), and for idiopathic hypersomnia in adults; Schedule III with boxed warning for respiratory depression and abuse/misuse and dispensed under a REMS (label).
What strengths does Xywav (calcium, magnesium, potassium, and sodium oxybates) come in?
Oral solution: 0.5 g/mL total salts (equivalent to 0.413 g/mL of oxybate) (label).

Snapshot

Class: Adjunctive therapy
Common US brands: Xywav
Therapeutic drug monitoring not routinely recommended.
Last reviewed: 2025-12-30

Label indications

Treatment of cataplexy or excessive daytime sleepiness (EDS) in patients 7 years of age and older with narcolepsy; treatment of idiopathic hypersomnia (IH) in adults; REMS-restricted (label).

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Clinical Highlights

Calcium, magnesium, potassium, and sodium oxybates (brand Xywav) is a nighttime medication indicated for Cataplexy or excessive daytime sleepiness (EDS) in patients 7 years of age and older with narcolepsy and for IH in adults (label). It contains the same active moiety as sodium oxybate: oxybate (gamma-hydroxybutyrate, GHB). Compared with Xyrem (sodium oxybate), Xywav delivers a substantially lower sodium burden at equivalent nightly doses, which may matter for patients who need sodium restriction due to hypertension, heart failure, kidney disease, or other cardiovascular risk (label/clinical).

Like other oxybate products, Xywav is a CNS depressant and a Schedule III controlled substance with a boxed warning for CNS/respiratory depression and abuse/misuse; it is dispensed only through a REMS due to risk of respiratory depression and misuse (label).
Practical use requires nightly planning. For narcolepsy, dosing is usually split into two doses (bedtime and 2.5 to 4 hours later). For IH, Xywav can be administered as a once-nightly or twice-nightly regimen in adults, depending on symptom pattern and tolerability (label).
Alcohol and other sedatives markedly increase risk and are avoided. Follow-up emphasizes next-day functioning, safe nighttime routines to reduce falls/injuries, and safe storage to reduce diversion (label/clinical).
The compare view, Xywav evidence feed, and print page help compare oxybate formulations and alternatives for narcolepsy/IH.

Dosing & Formulations

Oral solution: 0.5 g/mL total salts (equivalent to 0.413 g/mL of oxybate) (label). Narcolepsy: Adults start 4.5 g per night in two doses (2.25 g at bedtime and 2.25 g 2.5 to 4 hours later). Titrate by 1.5 g per night at weekly intervals to an effective range of 6–9 g per night; doses above 9 g per night or single doses above 6 g are not recommended (label).

Idiopathic hypersomnia (adults): May be given once nightly or as two doses per night; the dosing regimen can be adjusted based on response, sleep inertia/long sleep time, and tolerability (label).
Food reduces absorption; the first dose is taken at least 2 hours after eating (label).
Doses are prepared before bedtime and diluted with water; patients are typically counseled to take doses while in bed and avoid hazardous activities after dosing (label/clinical).

Monitoring & Risks

CNS and respiratory depression risk is the central safety concern; risk is higher with sedatives, alcohol, or underlying respiratory compromise (label/clinical). Sudden sleep onset after dosing can lead to falls and injuries; safe nighttime environment planning is clinically important (label/clinical).

Misuse/diversion risk is addressed through REMS enrollment, safe storage, and monitoring, especially when there is substance use risk (label/clinical).
Neuropsychiatric effects (confusion, anxiety, depression, parasomnias) can occur; monitoring is emphasized in serious mental illness and when other sedatives are present (label/clinical).
Hepatic impairment increases exposure; dosing adjustments and close monitoring are required (label).

Drug Interactions

Alcohol and sedative-hypnotics are avoided due to additive CNS depression and respiratory depression risk (label). Concomitant divalproex/valproate increases oxybate exposure; an initial dose reduction of at least 20% is recommended with close monitoring (label).

Other CNS depressants (benzodiazepines, opioids, some antipsychotics, sedating antidepressants) can increase sedation and respiratory risk; careful review is a routine safety step (label/clinical).

Practice Notes

Oxybate effectiveness can be substantial, but feasibility often hinges on REMS enrollment, safe storage, and the ability to avoid alcohol and other sedatives (clinical). For IH, aligning the regimen (once vs twice nightly) with sleep inertia and sleep maintenance patterns is a common clinical lever before adding additional hypnotics (label/clinical).

When obstructive sleep apnea is untreated or opioids are present, clinicians often reassess whether oxybate is appropriate due to respiratory risk (clinical).

References

XYWAV (calcium, magnesium, potassium, and sodium oxybates) oral solution prescribing information — DailyMed (2025)
Treatment of central disorders of hypersomnolence: an American Academy of Sleep Medicine clinical practice guideline — Journal of Clinical Sleep Medicine (2021)
Treatment OF Central Disorders OF Hypersomnolence: AN American Academy OF Sleep Medicine Systematic Review, Meta Analysis, AND Grade Assessment — Journal of Clinical Sleep Medicine (2021)
Efficacy AND Safety OF Calcium, Magnesium, Potassium, AND Sodium Oxybates (lower Sodium Oxybate [lxb]; JZP 258) IN A Placebo Controlled, Double Blind, Randomized Withdrawal Study IN Adults With Narcolepsy With Cataplexy — Sleep (2020)
Calcium, Magnesium, Potassium, AND Sodium Oxybates Oral Solution: A Lower Sodium Alternative FOR Cataplexy OR Excessive Daytime Sleepiness Associated With Narcolepsy — Nature and Science of Sleep (2022)