Zopiclone improves sleep quality and daytime well-being in insomniac patients: comparison with triazolam, flunitrazepam and placebo.

In a randomized, double-blind, parallel group study in private practice, zopiclone given for 28 days was compared with flunitrazepam, triazolam and placebo in its effect on quality of sleep and daytime well-being in 1507 patients suffering from insomnia. For quantitative assessment, patients were defined as responders according to either a shortening of sleep latency by at least 15 min, or prolongation of total sleep time by at least 20%, or reduction of the number of nocturnal awakenings to three or less and a fresh feeling in the morning, as well as lack of impairment in daytime well-being as a result of tiredness or anxiety. The responder rate tended to be higher with zopiclone (37.4%) than with flunitrazepam (30%) and triazolam (32.2%) and was significantly greater (p = 0.0017) than with placebo (26.8%). Daytime well-being was particularly responsive to zopiclone and most responsive in severe insomniacs. With the exception of those to triazolam, rates of response were most pronounced in patients with insomnia of a short duration (< or = 1 year) than in those with insomnia of a longer duration (> or = 1 year). Following discontinuation of treatment, all groups showed a moderate reduction in therapeutic effect, but no rebound insomnia occurred.