Full Prescribing Information Important Safety Information Medication Guide


XYREM Significantly Reduced Weekly Cataplexy Attacks

Two randomized, placebo-controlled trials demonstrated the efficacy of XYREM for the treatment of cataplexy in narcolepsy.

Trial 1 was a 4-week, double-blind, placebo-controlled trial of 136 narcolepsy patients with moderate-to-severe cataplexy (median of 21 attacks/week). At the end of week 4, a 69% reduction in attacks was seen with XYREM 9 g/night (P<0.005 vs placebo), and a 49% reduction was seen with XYREM 6 g/night (P<0.05 vs placebo). The greatest reduction was observed within 2 weeks.

However, additional improvements continued throughout the entire 4-week trial[1]. In XYREM clinical trials, ≈80% of patients maintained concomitant stimulant use[2].

  • After first initiating treatment and until certain that XYREM does not affect them adversely (eg, impair judgment, thinking, or motor skills), caution patients against hazardous activities requiring complete mental alertness or motor coordination such as operating hazardous machinery, including automobiles or airplanes. Also caution patients against these hazardous activities for at least 6 hours after taking the second nightly dose.
  • Patients should be queried about CNS depression-related events upon initiation of XYREM therapy and periodically thereafter.

The effective dose range of XYREM is 6 to 9 g/night

Gradual Return of Cataplexy Upon XYREM Discontinuation

Trial 2 documented the continued efficacy of XYREM after long-term use. Patients in this trial had been receiving open-label XYREM for an average of 21 months prior to study enrollment. At the beginning of the trial, they were randomized in a double-blind fashion to continued XYREM use or to placebo[2]. At the end of the 2-week study period, those who continued XYREM experienced no median increase in the number of cataplexy attacks/week, while those in the placebo group experienced a gradual return of cataplexy[2].

It is important to note that, although cataplexy gradually returned in the placebo group, no rebound cataplexy was seen following abrupt discontinuation of XYREM[2].

In XYREM clinical trials, ≈80% of patients maintained concomitant stimulant use[2].

Gradual Return of Cataplexy

The reduction in cataplexy attacks was maintained after an average of 21 months of XYREM use[2][3].Patients who remained on XYREM showed no median increase in cataplexy attacks.

Depression and Suicidality

  • The emergence of depression when patients are treated with XYREM requires careful and immediate evaluation. Patients with a previous history of a depressive illness and/or suicide attempt should be monitored especially carefully for the emergence of depressive symptoms while taking XYREM.

Use in Patients Sensitive to High Sodium Intake

  • XYREM has a high salt content. In patients sensitive to salt intake (eg, those with heart failure, hypertension, or renal impairment), consider the amount of daily sodium intake in each dose of XYREM.

To report an adverse event please call: 1-800-520-5568




  1. ^ The US XYREM® Multicenter Study Group. A randomized, double blind, placebo-controlled multicenter trial comparing the effects of three doses of orally administered sodium oxybate with placebo for the treatment of narcolepsy. Sleep. 2002;25:42–49.
  2. ^ XYREM® (sodium oxybate) [prescribing information]. Palo Alto, Calif: Jazz Pharmaceuticals, Inc.
  3. ^ The US XYREM® Multicenter Study Group. Sodium oxybate demonstrates long-term efficacy for the treatment of cataplexy in patients with narcolepsy. Sleep Med. 2004;5:119–123.
    The product information provided in this site is intended for residents of the United States only.

© 2015 Jazz Pharmaceuticals Inc.