Pharmacology · Z-drug hypnotics
Zopiclone !
A Z-drug for short-term insomnia, used in many countries but not marketed in the United States. It often leaves a bitter or metallic taste.
Updated 2026-11-01
The figure shows zolpidem, another Z-drug that acts at the same benzodiazepine site, bound to the human GABA-A receptor; no structure with zopiclone is available.
Mechanism of action
Zopiclone is an agonist at the benzodiazepine site of the GABA-A receptor and strengthens GABA's inhibition, which brings on sleep. It is a racemic mixture; its S-enantiomer is sold separately as eszopiclone.
- Binds the benzodiazepine site of the GABA-A receptor
- GABA's inhibition grows stronger
- Sleep comes sooner and lasts longer
Pharmacokinetics
- Absorption
- Given by mouth at bedtime
Indications
- Short-term treatment of insomnia (trouble falling asleep, staying asleep or waking early) Insomnia disorder →
Adverse effects
Common
- Bitter or metallic taste
- Dry mouth
- Next-day drowsiness
Contraindications
- Myasthenia gravis or other muscle weakness
- Sleep apnoea or breathing problems
- Liver problems
- Past reaction to similar sleeping medicines
Key interactions
- Alcohol
- Stronger effects, breathing problems and great difficulty waking
- Opioids and other sedatives
- Added sedation and breathing depression
What is monitored
- Duration of use (short courses)
- Next-day alertness
- Signs of dependence
Administration and safety
- Given by mouth at bedtime, for a short course
- No driving, cycling or machinery for 12 hours after a dose or while drowsy
- Reduced gradually when stopped after regular use
Nursing care
- Check how the person slept, next-morning alertness and falls
- Ask about alcohol and other sedatives
- Teach to take it only when a full night in bed is possible and not to drive the next morning if drowsy
- Teach to report sleepwalking, sleep-driving or other actions done while not fully awake
Pregnancy and breastfeeding
Not usually used in pregnancy; it may be given briefly when sleep problems are severe and other options have failed.
Test yourself
Think of the answer, then tap the question to see it.
Which taste effect is common with zopiclone?
A bitter or metallic taste.
Which muscle disease makes zopiclone unsuitable?
Myasthenia gravis.
Why is alcohol avoided with zopiclone?
It strengthens its effects, can cause breathing problems and makes waking very hard.
Related drugs
Related conditions
← Back to the class: Z-drug hypnotics
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: Zopiclone: a medicine used to treat insomnia (NHS, 2026); Goodman & Gilman's The Pharmacological Basis of Therapeutics, 14th ed., ch. 22 (McGraw Hill, 2023); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026).
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Representative model, for educational purposes only.