Yamadera H, Kato M, Tsukahara Y, Okuma T
Department of Neuropsychiatry, Nippon Medical School, Tokyo, Japan.
Nihon Shinkei Seishin Yakurigaku Zasshi. 1995 Aug;15(4):355-61.
Zopiclone is a cyclopyrrolone derivative which possesses hypnotic activity. This drug is known to increase the slow sleep stage compared to benzodiazepines in polysomnography. The subjects were 10 right-handed healthy male volunteers aged 21-23 years. Double-blind crossover trials with placebo control were conducted in a random sequence at intervals of 1 week. Zopiclone 7.5 mg and placebo were administered as single oral doses. Three-minute vigilance controlled EEGs at before and at 1, 3, and 5 h after drug administration, and the response times were recorded. One minute out of the 3-minute EEGs was analyzed with FFT and the power spectrum was obtained. Then the absolute amplitude power (microV) was calculated. These results were subjected to Student's t-test (double difference) and displayed with topographic maps (t statistic significance probability mapping). Zopiclone prolonged the latency of the response time, and increased the amount of delta absolute amplitude power over the right central region, beta 1 absolute amplitude power over the left central region and beta 2 absolute amplitude power over the right central area along with decreased alpha absolute amplitude power over the occipital region and theta power over the left frontal pole area after 1 h, when the peak pharmacological effect was expected. The EEG profiles of zopiclone were different from that of diazepam reported previously concerning the increase in delta activity.
