Zopiclone as a preoperative night hypnotic: a double-blind comparison with temazepam and placebo.

We have examined the hypnotic effects of zopiclone 7.5 mg and temazepam 20 mg compared with placebo in a double-blind, randomized, clinical study of 60 patients on the night before operation. Evaluation was both subjective (visual analogue scales and a sleep questionnaire), to measure the quality of sleep, and objective (critical flicker fusion, object recall and paired associates tasks), to measure residual impairment. We found that zopiclone was an effective single-dose hypnotic with similar residual effects to the benzodiazepine and it may therefore provide a suitable alternative to benzodiazepines.