The nightly administration of sodium oxybate results in significant reduction in the nocturnal sleep disruption of patients with narcolepsy

BackgroundPrevious studies indicate that nightly sodium oxybate administration reduces nocturnal sleep disruption in narcolepsy. The present study provided an opportunity to further characterize these sleep-related effects in patients with narcolepsy during treatment with sodium oxybate as monotherapy or in combination with modafinil.MethodsThis double-blind, placebo-controlled study enrolled 278 patients with narcolepsy taking modafinil 200–600 mg daily for the treatment of excessive daytime sleepiness (EDS). Following a baseline polysomnogram (PSG) and Maintenance of Wakefulness Test (MWT), patients were randomized to receive treatment with: (1) placebo, (2) sodium oxybate, (3) modafinil, or (4) sodium oxybate + modafinil. PSGs and MWTs were repeated after 4 and 8 weeks. Other efficacy measures included Epworth Sleepiness Scale scores and daily diary recordings.ResultsAfter 8 weeks, significant changes in sleep architecture among patients receiving sodium oxybate and sodium oxybate/modafinil included a median increase in Stage 3 and 4 sleep (43.5 and 24.25 min, respectively) and delta power and a median decrease in nocturnal awakenings (6.0 and 9.5, respectively). No significant changes in PSG parameters were noted in patients treated with placebo or modafinil alone.ConclusionsIn addition to its established efficacy for the treatment of cataplexy and EDS, nightly sodium oxybate administration significantly reduces measures of sleep disruption and significantly increases slow-wave sleep in patients with narcolepsy.