Zopiclone (brand names Zimovane and Imovane) is a nonbenzodiazepine hypnotic agent used in the treatment of insomnia. Zopiclone is molecularly distinct from benzodiazepine drugs and is classed as a cyclopyrrolone. However, zopiclone increases the normal transmission of the neurotransmitter gamma-aminobutyric acid in the central nervous system, via modulating benzodiazepine receptors in the same way that benzodiazepine drugs do.
As zopiclone is sedating, it is marketed as a sleeping pill. It works by causing a depression or tranquilization of the central nervous system. After prolonged use, the body can become accustomed to the effects of zopiclone. When the dose is then reduced or the drug is abruptly stopped, withdrawal symptoms may result. These can include a range of symptoms similar to those of benzodiazepine withdrawal. Although withdrawal from therapeutic doses of zopiclone and its isomers (i.e. eszopiclone) do not typically present with convulsions and are therefore not considered life-threatening