Sodium oxybate, Sodium oxybate is the sodium salt of γ-hydroxybutyric acid (GHB). Brand names; Xyrem, Alcover. used at night to treat the disruption of sleep continuity seen in narcolepsy. It is a difficult drug to use, as it has a very 87 short half-life, so the patient needs to wake up during the night to take a second dose. However, it has a profound effect in consolidating REM sleep and increasing slow-wave sleep (SWS), and reduces cataplexy and sometimes daytime sleepiness.