Zopiclone
Zopiclone is a licensed cyclopyrrolone hypnotic (a 'Z-drug') used for short-term treatment of insomnia. It shortens sleep latency and reduces night waking. Despite being non-benzodiazepine, it acts on the same receptor and carries dependence potential and a risk of complex sleep behaviours.
01 Overview
Zopiclone is a widely prescribed hypnotic in Europe and many other regions for short-term management of insomnia. It is effective at reducing the time taken to fall asleep and improving sleep continuity, and is generally intended for courses of no more than a few weeks.
Although chemically distinct from benzodiazepines, it acts at the same GABA-A benzodiazepine site. It shares their dependence liability, tolerance and withdrawal, and can produce complex sleep behaviours such as sleep-walking, sleep-driving and sleep-eating with no memory of the event. A characteristic bitter or metallic taste is common.
02 Mechanism
Positive allosteric modulator at the GABA-A benzodiazepine receptor site (cyclopyrrolone class), enhancing inhibitory neurotransmission to promote sleep.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Therapeutic (adult) | 3.75–7.5 mg/day | Oral | Taken at bedtime; 3.75 mg in the elderly or hepatic impairment. |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Reduced sleep latencyFalls asleep faster, shown in controlled trials. | shorter time to sleep | Clinical | |
| Improved sleep continuityFewer nocturnal awakenings and longer total sleep. | Clinical | ||
| SedationGeneral CNS depression that can persist into the next morning. | Clinical |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Dependence and rebound insomniaTolerance and dependence develop with continued use; stopping can cause rebound insomnia and withdrawal. | Moderate | Common with prolonged use | Clinical | |
| Complex sleep behavioursSleep-walking, sleep-driving, sleep-eating and other activities performed while not fully awake, with amnesia for the event. | Severe | Rare | Observational | |
| Next-day sedation and fallsResidual drowsiness impairing driving and, especially in the elderly, increasing fall risk. | Moderate | Common | Clinical | |
| Additive respiratory depressionDangerous with opioids or alcohol. | Life-threatening | High risk in combination | Clinical |