Objective:

Review the scientific literature regarding the impact of oxybate dose and regimen on sleep quality, sleep architecture, and disrupted nighttime sleep (DNS) in patients with narcolepsy.

Background:

Sleep disturbances in narcolepsy encompass self-reported sleep quality, sleep architecture, and DNS. DNS is associated with frequent sleep stage shifts and awakenings/arousals on polysomnography. Sodium oxybate (SXB; Xyrem^®), dosed twice nightly, is approved to treat excessive daytime sleepiness and cataplexy in patients with narcolepsy. Once-nightly sodium oxybate (ON-SXB; Lumryz™) and low-sodium oxybate (Xywav^®) have been approved for the same indication. Both SXB and ON-SXB improve DNS. Therefore, a review of oxybate’s impact on sleep disturbances in patients with narcolepsy is timely.

Design/Methods:

PubMed was searched for articles on oxybate, narcolepsy, and DNS. Key data from 5 studies are presented. 

Results:

Participants in study 1 (SXB, ≥16 years) showed significant improvements in self-reported sleep quality, increases in N3, and decreases in REM and sleep stage shifts/hour. Participants in study 2 (SXB, ≥18 years) demonstrated significantly improved sleep quality relative to placebo, increases in N3, and decreases in REM and sleep stage shifts. Participants in study 3 (ON-SXB, ≥16 years) showed significantly improved sleep quality; increases in N3; and decreases in REM, N1, arousals, and sleep stage shifts. In study 4 (open-label, SXB), participants demonstrated improved sleep quality, significantly increased N3 and decreased REM in the second half of the night, and decreased awakenings. In study 5 (SXB, pediatric), participants (SXB-naive at study entry) showed decreases in N1%, REM%, and arousals and increases in N3%.

Conclusions:

A clinical data review shows that oxybate, independent of once- or twice-nightly dosing, is effective in improving sleep, measures of sleep architecture, and DNS in participants with narcolepsy.