01 Feb Pharmacological therapy for Obstructive Sleep Apnoea
It is well established that during obstructive sleep apnoea (OSA) the upper airway collapses, obstructing airflow into the lungs, causing reductions in oxygen and generally a brief awakening. Part of the collapse is due to the relaxation of the muscles that hold the airway open which occurs during sleep.
What if there was a drug to take which would target those muscles specifically and hold the airway open while the rest of the body could relax and sleep?
Carley D Wet al have recently published a new study in the Journal of Sleep which looked at a drug called dranabinol which is thought to supress certain input to the medulla which controls breathing. By doing so the respiration changes during sleep may be stabilised potentially reducing the severity of sleep apnoea.
The authors found this was the case by comparing a placebo and two doses of the drug. They found mild reduction in Apnoea-Hypopnoea Index (AHI) (2 events /hr in the small dose, 4 events/hr in the high dose). Some participants did respond better than others (up to 50% reduction in AHI), and responders tended to have the biggest reductions in REM sleep AHI.
As well as looking at AHI changes, they found strong beneficial effect on subjective sleepiness as measured by Epworth Sleepiness Scale (ESS). There was however no effect on objective wakefulness as measured by Maintenance of Wakefulness Test (MWT) or on sleep architecture. No differences in arousal index, total sleep time, sleep stage proportion or oxygen saturation. The receivers of the higher dose also reported being extremely satisfied with the treatment 6 times more than the other groups.
Interestingly these results show that while mildly reducing the AHI mildly, subjective sleepiness in OSA may be treated without completely fixing the AHI, and without necessarily taking stimulants.
David W Carley, Bharati Prasad, Kathryn J Reid, Roneil Malkani, Hryar Attarian, Sabra M Abbott, Boris Vern, Hui Xie, Chengbo Yuan, Phyllis C Zee; Pharmacotherapy of Apnea by Cannabimimetic Enhancement, the PACE Clinical Trial: Effects of Dronabinol in Obstructive Sleep Apnea, Sleep, Volume 41, Issue 1, 1 January 2018, zsx184, https://doi.org/10.1093/sleep/zsx18
Sigrid C Veasey; Obstructive sleep apnea drug therapy: apnea–hypopnea index leaves us high and dry, Sleep, Volume 41, Issue 1, 1 January 2018, zsy014, https://doi.org/10.1093/sleep/zsy014