Zopiclone to treat insomnia in older adults: A systematic review

Considering the global increase in use of Z-drugs to treat insomnia, the study objective was to conduct a systematic review on the efficacy and safety of zopiclone to treat sleep disorders in older adults compared to other sedative-hypnotics, to placebo or to non-pharmacological interventions. The literature search for original reports - clinical trials, cohort studies and cross-sectional, observational investigations - was done in eleven databases and web search engines followed PRISMA guidelines, and methodological quality was assessed using the Risk of Bias tool in the Cochrane Reviewers' Handbook. The search resulted in 12 randomized, placebo-controlled clinical trials along with 2 open studies and 2 observational reports. Overall, the studies suggest that zopiclone is effective to treat insomnia by reducing sleep latency, nocturnal awakenings and wake time after sleep onset while increasing total sleep time, with probable effects on sleep architecture. Zopiclone was found to be fairly tolerated, to induce a low rate of adverse events with non-severe impact on psychomotor or cognitive performance and to produce no major harm to the overall well-being and daily living abilities. However, the quality of most studies was classified as low or unclear. Though the studies available support benefits from zopiclone use, there is still a need for further evidence on long-term effects, tolerability and safety in the treatment of older adults by means of high-quality trials.