Zopiclone
Zopiclone was developed and first introduced in 1986 by Rhône-Poulenc S.A., now part of Sanofi-Aventis, the main worldwide manufacturer. Initially, it was promoted as an improvement on benzodiazepines, but a recent meta-analysis found it was no better than benzodiazepines in any of the aspects assessed. On April 4, 2005, the U.S. Drug Enforcement Administration listed zopiclone under schedule IV, due to evidence that the drug has addictive properties similar to benzodiazepines.
Zopiclone
Zopiclone is indicated for the short-term treatment of insomnia where sleep initiation or sleep maintenance are prominent symptoms. Long-term use is not recommended, as tolerance, dependence, and addiction can occur with prolonged use. One low quality study found that zopiclone is ineffective in improving sleep quality or increasing sleep time in shift workers - more research in this area has been recommended.