Efficacy of zopiclone in middle age.

Effects of zopiclone (5.0, 7.5, and 10 mg) on sleep and on performance were studied in middle-aged subjects. Zopiclone (5.0-10.0 mg) reduced awake activity and the number of awakenings, and increased the duration of stage 2 sleep. The appearance of REM sleep was delayed, but this effect was without reduction over the whole night. There were no impairments in the digit symbol substitution test when zopiclone was compared with placebo, although there were less substitutions with 10.0 mg than with 5.0 mg. Symbol copying and choice reaction time were unaltered. Zopiclone would appear to be a useful hypnotic for those involved in skilled work. Based on the results obtained in healthy volunteers, the 5.0 mg dose would be appropriate for many; if in insomniac patients, 7.5 mg was needed, then it is likely to be free of undue impairment of performance the next day.