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

Background: Previous 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. Methods: This 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. Results: After 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. Conclusions: In 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. (C) 2009 Elsevier B.V. All rights reserved.