Zopiclone

Description

Zopiclone Overview

Zopiclone (marketed as Zimovane) is a non-benzodiazepine sedative from the cyclopyrrolone class, often prescribed short-term for treating insomnia. It acts as a GABA-A receptor agonist, promoting calming effects by enhancing GABA activity in the brain. Compared to zaleplon, zopiclone has a longer duration due to slower elimination. It is part of the “Z-drug” family and differs from zolpidem and zaleplon, which mainly target the alpha-1 subunit of the GABA receptor.

After ingestion, zopiclone is about 80% bioavailable and binds 40–80% to plasma proteins. It is metabolized into two compounds: N-oxide-zopiclone (active) and N-desmethyl-zopiclone (inactive). The drug and its active metabolite have a half-life ranging from 3.5 to 6.5 hours. Zopiclone is classified as a prescription-only medication.

Dosage and Use

The recommended dose for adults with insomnia is 7.5 mg taken at bedtime, with 3.75 mg as a lower-dose option. It is not advised during pregnancy or breastfeeding due to potential transfer to the fetus or infant. Studies have shown that a 7.5 mg dose can impair driving ability, memory, and motor skills, especially when combined with alcohol or other central nervous system depressants. The residual effects of zopiclone last longer than those of zaleplon.

Safety Profile

Zopiclone’s safety concerns include risks of rebound insomnia, withdrawal, residual sedation, and behavioral changes like agitation or vivid dreams. While rare, dependence has been reported. A large monitoring study involving over 13,000 patients found very few cases suggesting possible dependence, though one fatal overdose involving zopiclone and other medications was recorded. Users are advised not to combine it with alcohol or other drugs due to increased risk of adverse effects.