Description: Zopiclone is a short-acting sedative-hypnotic used in the short-term treatment of insomnia. It is in a novel class of CNS depressants called cyclopyrrolones, which act on the same receptor sites as benzodiazapines. Zopiclone became commercially available in Europe in 1989 and in the U.S. in 2005. (4-methyl-1-piperazinecarboxylic acid 6-(5-chloro- 2-pyridinyl)-6,7-dihydro-7-oxo-5H-pyrrolo[3,4-b] pyrazin-5-yl ester)