New knowledge on
hypnotics and their effects on the phenotypic causes of
obstructive sleep apnea indicate that
zolpidem has therapeutic potential for certain patients. Specifically,
zolpidem increases the threshold for arousal threshold and pharyngeal dilator muscle responsiveness. However, the effects of a standard dose of
zolpidem (10 mg) on
obstructive sleep apnea severity and symptoms have not been investigated. In an open-label pilot study, 12 unselected people with
obstructive sleep apnea were recruited following a diagnostic in-laboratory sleep study. Participants then returned for a single-night sleep study in which 10 mg of
zolpidem was given just prior to sleep. Tolerability, next-day
sleepiness and the effects of
zolpidem on polysomnography variables were assessed.
Zolpidem was well tolerated and significantly improved the sleep efficiency compared with the no-drug night (77 ± 12% versus 84 ± 9%, p = 0.005). Individual responses on
obstructive sleep apnea severity to
zolpidem in this unselected
obstructive sleep apnea patient population were variable with no overall systematic difference in
apnea-hypopnea index (29 ± 18.2 events per hr versus 33 ± 28 events per hr, p = 0.45) or other key respiratory parameters (e.g. event duration or
hypoxemia). Next-day
sleepiness assessed via the Karolinska
Sleepiness Scale was not different between visits (4 ± 1 versus 4 ± 2, p = 0.85). These findings provide the first insight into the effects of a standard dose of
zolpidem in
obstructive sleep apnea, and highlight its tolerability and potential to improve sleep quality. The variable effects on
obstructive sleep apnea severity observed in this pilot also underscore the need for larger trials that incorporate phenotypic characterisation (e.g. arousal threshold, Pcrit and muscle responsiveness) to understand inter-individual heterogeneity and the therapeutic potential of
zolpidem for certain people with
obstructive sleep apnea.