Desmethylzopiclone, also known as SEP-174559, is an active metabolite of the sedative-hypnotic drug zopiclone.
Unlike its parent compound, which is a largely non-selective benzodiazepine receptor agonist, desmethylzopiclone is a selective partial agonist at the benzodiazepine site of ñ3-containing GABA receptor subtypes. It is also an antagonist to nicotinic acetylcholine receptors and NMDA receptors.
Desmethylzopiclone has been described as a potential anxio-selective metabolite of zolpiclone owing to its selective affinity for the modulation of ñ3-containing GABA receptor subtypes. Modulation of these GABA<sub>A</sub> subtypes have been implicated as key mediators of the anxiolytic effects of benzodiazepines.
A method for the quantification of desmethylzopiclone from urine has been developed and may serve useful in forensic analysis of cases involving zolpiclone intoxication.