About Xyrem

What is XYREM?

XYREM is indicated for the treatment of cataplexy in narcolepsy1

XYREM is indicated for the treatment of excessive daytime sleepiness (EDS) in narcolepsy1

XYREM (sodium oxybate) oral solution may only be dispensed to patients enrolled in the XYREM® REMS Program1


  • An oral solution taken at night1
  • The sodium salt of gamma hydroxybutyrate, an endogenous compound and metabolite of gamma-aminobutyric acid (GABA)1
  • Recommended by the American Academy of Sleep Medicine as a standard of care for EDS and cataplexy in narcolepsy2
*US Food and Drug Administration.

XYREM Proposed Mechanism of Action

The mechanism of action of XYREM in the treatment of excessive daytime sleepiness (EDS) in narcolepsy and cataplexy in narcolepsy is unknown1

*Derived from animal studies. GABA = gamma-aminobutyric acid.

XYREM Pharmacokinetics: Absorption and Elimination

Demonstrated to be rapidly absorbed and eliminated1

  • Rapid absorption with absolute bioavailability of about 88%1
    • Tmax: 30–75 min
    • t½: 30–60 min
  • In a clinical study, 12 healthy volunteers were given 2 equal doses of XYREM 4 hours apart3,4
  • Nonlinear pharmacokinetics: doubling the dose from 4.5 g to 9 g1,3
    • Increased blood levels by 3.7-fold1
    • Increased mean Cmax 2.4- to 2.9-fold3
*Mean oxybate concentration (± SEM) vs time after total doses of XYREM 4.5 g and 9 g administered in 2 equal doses given 4 hours apart in 12 healthy volunteers. Single doses greater than 4.5 g have not been studied.1,3,4

XYREM Pharmacokinetics:
Food Effect

Shown to have reduced bioavailability when taken with food1,5

  • Decreased mean peak plasma concentrations1,5
  • Decreased mean amount of XYREM exposure1,5
    • Implications for patients1:
      Because food significantly reduces the bioavailability of sodium oxybate, patients should be reminded to wait at least 2 hours after eating before they take their first dose of XYREM

XYREM Dosing and Titration

How to dose and titrate your patients taking XYREM1

  • The recommended starting dosage is 4.5 g per night, taken in 2 equal, divided doses1
    • Dose 1: 2.25 g at bedtime*
    • Dose 2: 2.25 g taken 2.5 to 4 hours later*
*Patients should take both doses of XYREM while in bed and lie down immediately after dosing.
  • Titrate the dosage to the effective range of 6 to 9 g per night1
    • The FDA-approved maximum dose of XYREM is 9 g per night
  • Increase the dosage by 1.5 g per night at weekly intervals1
    • Additional 0.75 g at bedtime
    • Additional 0.75 g taken 2.5 to 4 hours later
  • Patient follow-up every 3 months is recommended1

Important administration instructions1

  • Patients should prepare both nighttime doses prior to bedtime1
  • Patient should take both doses of XYREM while in bed and lie down immediately after dosing, as XYREM may cause them to fall asleep abruptly without first feeling drowsy1
    • Patients will often fall asleep within 5 to 15 minutes
    • Rarely, patients may take up to 2 hours to fall asleep
  • Patients should not engage in hazardous occupations or activities requiring complete mental alertness or motor coordination for at least 6 hours after taking the second nightly dose of XYREM1
  • XYREM is a clear to slightly opalescent oral solution, in a concentration of 0.5 g per mL. Each dose of XYREM should be diluted with approximately ¼ cup of water (approximately 60 mL) in the empty pharmacy vials provided.1 Bottle size and shape may vary, but the method of dispensing is always the same.