Zopiclone: a new nonbenzodiazepine hypnotic used in general practice.

Ninety-one insomniacs completed a four-week study of the efficacy and safety of zopiclone (Z), 7.5 mg. Patients were randomly allocated to one of two groups, each of which received placebo (P) during one week of the study. Forty-six subjects received medication in the sequence of ZPZZ, and 45 received it in the sequence of ZZPZ. Twice each week, patients filled out presleep and postsleep questionnaires and reported their morning complaints. Compared with placebo, zopiclone produced statistically significant improvements (P less than 0.05) in sleep induction time, duration of sleep, number of awakenings per night, quality and soundness of sleep, morning state of rest, and daytime sleepiness. Headache, dizziness, nausea, and bitter taste were the predominant complaints. Zopiclone can be considered an efficient and safe hypnotic for chronic insomnia.