Zopiclone, which is on the market in Europe and Asia but not the United States, is a cyclopyrrolone that acts at the GABAA–benzodiazepine receptor complex, but possibly at a different binding domain or by producing different conformational changes than the benzodiazepines.55 It is rapidly absorbed, with peak plasma concentrations occurring in 0.5 to 2 hours.56 Bioavailability is about 80%, implying that the first-pass effect is relatively small. It is very lipophilic and enters rapidly into the central nervous system. Protein binding is approximately 45%. It has two major metabolites, the N-oxide, which has lower pharmacologic activity, and the inactive N-desmethyl derivative, which along with various minor metabolites are excreted primarily by the kidneys and lungs.
Hypnotic Drugs,change the users perception of reality wildly, in some cases mile to having complete audio and visual hallucinations , in some cases called a " reality break" this is due to the minds receptors, of what it perceives readily change due to absorbing the Z - hypnotic drug such as Zolpidem sleeping pills or Zopiclone sleeping tablets. This is uncommon but in large doses, this is achievable but very dangerous.
Eszopiclone, the S-isomer of racemic zopiclone, is marketed in the United States as Lunesta. Peak concentrations are achieved in 1 hour, with an elimination half-life of approximately 6 hours. It is weakly bound to protein, and metabolized via oxidation and demethylation; its biotransformation is attributed to CYP3A4 and CYP2E1.57 Eszopiclone has been found to have effectiveness without tolerance for at least 6 months,58 and was the first drug in the United States to have no limitation on duration of administration by the FDA.