Effect of naloxone on diurnal polysomnographic manifestations of hypersomnia with sleep apnoea.

A simple blind study with small doses of naloxone (0.8-1.6 mg i.v.) was carried out in 11 patients with hypersomnia with sleep apnoea (HSA). The effect was studied by diurnal polysomnography. It was found that the administration of naloxone was followed by significant prolongation of wakefulness and by significant shortening of the total duration of the second stage of NREM sleep. The duration of the apnoeic episodes was also significantly shortened after naloxone, although their number did not alter. Increased activity of the endorphinergic system (which naloxone inhibits by receptor competition) evidently plays a role in the pathophysiology of HSA.