A dose-response study in situational insomnia with zopiclone, a new tranquilizer

Patients scheduled for next-day elective surgery were included in a randomized double-blind trial that compared the hypnotic and adverse effects of a placebo and four doses (3,5,6,9,13.5 mg) of a new compound, zopliclone. Sleep patterns were evaluated using a questionnaire; side effects were noted, and tests evaluating coordination and alertness were performed. Except for dreams and morning responses, there were significant differences in sleep indices at all dose levels. The 3.5-mg dose produced some significant differences compared with the placebo. All responses to the higher three doses were statistically significant; however, there was only a slight increase in effectiveness between 6 and 9 mg. Alertness, coordination tests, blood pressure, and adverse effects did not differ significantly among doses, except for the incidence of drowsiness and a bitter after-taste in the mouth.