Relationship between the effects of a hypnotic drug, zopiclone, on polysomnography and on daytime EEGs.

Author(s): Yamadera H, Kato M, Tsukahara Y, Kajimura N, Okuma T

Affiliation(s): Department of Neuropsychiatry, Nippon Medical School, Tokyo, Japan. yamadera@nms.ac.jp

Publication date & source: 1997, Neuropsychobiology., 35(3):152-5.

Publication type: Clinical Trial; Randomized Controlled Trial

The correlation between the effects of zopiclone (ZPC), a nonbenzodiazepine hypnotic drug, on sleep polysomnograms and on daytime EEGs was examined in 12 healthy adult male volunteers. Sleep polysomnograms were recorded after a single oral administration of ZPC 10 mg or placebo according to the double-blind crossover method. Daytime EEGs were recorded after the administration of ZPC, 7.5 mg, or placebo in the same manner, and recorded for 3 min with closed eyes at rest. Then, square roots of the absolute power (amplitude) of the delta-, theta-, alpha-, and beta-activities were calculated from the power spectrum obtained by the fast Fourier transform method. As a result, ZPC decreased the percentage of stage 1 sleep in total sleep time, while it increased the percentage of stage 2, total sleep time, and time of slow wave sleep in the first and second sleep cycles (SWS 1 and 2). Changes in SWS 1 and 2 correlated positively with the amplitude changes in daytime resting delta-activity. This indicates that the increase of SWS due to ZPC could be related to the change of delta-activity in the daytime resting EEG.