Differential Effects of Sodium Oxybate and Baclofen

1071 GABAB Agonist, Sleep, and the EEG—Vienne et al INTRODUCTION Sodium oxybate (SO, sodium salt of γ-hydroxybutyric acid [GHB]) is an endogenously produced fatty acid, recently approved for the treatment of narcolepsy with cataplexy.1 GHB has been shown to increase slow wave sleep (SWS) and EEG delta power (0.75-4.5 Hz), in a dose-dependent manner in healthy subjects2-4 and in patients with narcolepsy and fibromyalgia.5-7 The physiological increase of SWS and EEG delta power is proposed to represent cortical recovery from prior wakefulness.8,9 Like other restorative functions, sleep is homeostatically regulated. Sleep loss produces proportional increase in the tendency to fall asleep10 and in the EEG delta power during recovery sleep.11 Conversely, an afternoon/evening nap reduces the SWS duration and EEG delta power during the subsequent nocturnal sleep.12 EEG delta power varies as a function of the sleep-wake history in a highly predictive manner not only in humans but in all mammalian species studied so far, and is therefore widely used as a marker of sleep need/intensity.13-15 DIFFERENTIAL EFFECTS OF SODIUM OXYBATE AND BACLOFEN