sodium oxybate extended-release

General information

• Class: Adjunctive therapy
• Common US brands: Lumryz
• Typical dose range: Adults: start 4.5 g once per night. Increase by 1.5 g per night at weekly intervals to a recommended range of 6–9 g once nightly; doses higher than 9 g per night have not been studied and should not ordinarily be administered (label).
• Therapeutic drug monitoring not routinely recommended.
• Last reviewed: 2026-02-22

Dosing & forms

• Forms/strengths: Extended-release oral suspension powder packets: 4.5 g, 6 g, 7.5 g, and 9 g (label).
• Frequency: Adults: start 4.5 g once per night. Increase by 1.5 g per night at weekly intervals to a recommended range of 6–9 g once nightly; doses higher than 9 g per night have not been studied and should not ordinarily be administered (label).
• Typical range: Adults: start 4.5 g once per night. Increase by 1.5 g per night at weekly intervals to a recommended range of 6–9 g once nightly; doses higher than 9 g per night have not been studied and should not ordinarily be administered (label).

Mechanism (brief)

Nighttime CNS depressant (sodium oxybate; oxybate/GHB) once-nightly extended-release oral suspension indicated for cataplexy or excessive daytime sleepiness in narcolepsy (patients 7+); Schedule III with boxed warning for respiratory depression and abuse/misuse and dispensed under a REMS. Alcohol is contraindicated due to dose-dumping risk (label).

Metabolism & Half‑life

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

Therapeutic Drug Monitoring (TDM)

Recommended: No

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).
• Mood and neuropsychiatric symptom monitoring (label/clinical).
• Hepatic impairment assessment and appropriateness of initiation (label).

Sources

• LUMRYZ (sodium oxybate) for extended-release oral suspension 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)
• Once-nightly sodium oxybate (FT218) demonstrated improvement of symptoms in a phase 3 randomized clinical trial in patients with narcolepsy — Sleep (2021)