Zopiclonebelongs to the group of medicines called central nervous system (CNS) depressants (medicines that make you drowsy or less alert). zopiclone is used to treat insomnia (trouble in sleeping). Zopiclone helps you get to sleep faster and sleep through the night. In general, when sleep medicines are used every night for a long time, they may lose their effectiveness. In most cases, sleep medicines should be used only for short periods of time, such as 1 or 2 days, and generally for no longer than 1 or 2 weeks.