EFFECTS OF NALOXONE ON UPPER AIRWAY COLLAPSIBILITY IN NORMAL SLEEPINGSUBJECTS

Background - To evaluate the possible influence of endorphin release o n upper airway collapsibility the effects of naloxone, an opiate recep tor antagonist, were measured. Methods - The effects of naloxone on up per airway collapsibility were studied in five normal sleeping men in a pilot study. During a sleep fragmentation night the subjects receive d either naloxone or a volume matched saline placebo in a double blind crossover design. Critical pressure (Pcrit) was measured during a mor ning nap following sleep fragmentation. Results - The plasma levels of endorphins increased during sleep fragmentation nights. Pcrit was sig nificantly greater after placebo than after naloxone infusion. Conclus ions - Naloxone may reduce upper airway collapsibility in normal sleep ing subjects following sleep fragmentation.