Zopiclone versus nitrazepam: a double-blind comparative study of efficacy and tolerance in elderly patients with chronic insomnia.

A randomized, double-blind, comparative trial of zopiclone versus nitrazepam was conducted in 74 geriatric chronic insomniac patients. Following a 7-day wash-out period, two parallel groups, successively received a placebo for 7 days, then either 7.5 mg zopiclone or 5 mg nitrazepam for another 7-day period. Efficacy on sleep was assessed by a sleep analogue scale and the Spiegel Sleep Questionnaire, residual effects by psychometric tests and tolerance by a standardized question, as well as by clinical and laboratory tests. Zopiclone and nitrazepam were more active than placebo on all tests of efficacy. In contrast with nitrazepam, zopiclone was devoid of effect on neurological function. In addition, the condition on awakening was better with zopiclone.