sodium oxybate

Adjunctive therapy • Brands: Xyrem

Last reviewed: 2026-02-22

General information

Class: Adjunctive therapy
Common US brands: Xyrem
Typical dose range: Adults: start 4.5 g per night in two doses (2.25 g at bedtime and 2.25 g 2.5–4 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 are not ordinarily administered (label).
Therapeutic drug monitoring not routinely recommended.
Last reviewed: 2026-02-22

Dosing & forms

Forms/strengths: Oral solution: 0.5 g/mL (label).
Frequency: Adults: start 4.5 g per night in two doses (2.25 g at bedtime and 2.25 g 2.5–4 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 are not ordinarily administered (label).
Typical range: Adults: start 4.5 g per night in two doses (2.25 g at bedtime and 2.25 g 2.5–4 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 are not ordinarily administered (label).

Mechanism (brief)

Nighttime CNS depressant (sodium oxybate; oxybate/GHB) indicated for cataplexy and excessive daytime sleepiness in narcolepsy (patients 7+); Schedule III with boxed warning for CNS depression and abuse/misuse, and dispensed under a REMS due to risk of respiratory depression and misuse.

Metabolism & Half‑life

Metabolism: Non-CYP metabolism (GHB metabolic pathways)
Half‑life: Single-dose range 0.5–1 h

Therapeutic Drug Monitoring (TDM)

Recommended: No

View labelExact

Monitoring highlights

Respiratory risk and CNS depressant co-medication review (label/clinical).
Safe storage and misuse/diversion monitoring consistent with REMS (label/clinical).
Nighttime fall risk assessment and environment planning (clinical).
Hepatic impairment assessment for dosing and safety (label).
Review of interaction with divalproex/valproate if co-prescribed (label/clinical).

Sources

XYREM (sodium oxybate) 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)
Sodium oxybate improves excessive daytime sleepiness in narcolepsy — Sleep (2006)

General information

Class: Adjunctive therapy

Common US brands: Xyrem

Typical dose range: Adults: start 4.5 g per night in two doses (2.25 g at bedtime and 2.25 g 2.5–4 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 are not ordinarily administered (label).

Therapeutic drug monitoring not routinely recommended.

Last reviewed: 2026-02-22

Dosing & forms

Forms/strengths: Oral solution: 0.5 g/mL (label).

Frequency: Adults: start 4.5 g per night in two doses (2.25 g at bedtime and 2.25 g 2.5–4 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 are not ordinarily administered (label).

Typical range: Adults: start 4.5 g per night in two doses (2.25 g at bedtime and 2.25 g 2.5–4 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 are not ordinarily administered (label).

Monitoring highlights

Respiratory risk and CNS depressant co-medication review (label/clinical).

Safe storage and misuse/diversion monitoring consistent with REMS (label/clinical).

Nighttime fall risk assessment and environment planning (clinical).

Hepatic impairment assessment for dosing and safety (label).

Review of interaction with divalproex/valproate if co-prescribed (label/clinical).