Pharmacology · Z-drug hypnotics
Eszopiclone !
The S-enantiomer of zopiclone, a Z-drug for falling and staying asleep. A bitter taste and next-day impairment are common.
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 eszopiclone is available.
Mechanism of action
Eszopiclone is an agonist at the benzodiazepine site of the GABA-A receptor and strengthens GABA-gated chloride currents. It shortens the time to fall asleep and improves sleep maintenance.
- Binds the benzodiazepine site of the GABA-A receptor
- GABA's chloride current grows stronger
- Faster sleep onset and fewer awakenings
Pharmacokinetics
- Metabolism
- In the liver by CYP3A4 and CYP2E1
- Half-life
- About 6 hours
Indications
- Insomnia: difficulty falling or staying asleep Insomnia disorder →
Adverse effects
Common
- Unpleasant (bitter) taste
- Headache and dizziness
- Drowsiness
Contraindications
- Previous complex sleep behaviour after eszopiclone
- Hypersensitivity to eszopiclone
Key interactions
- Alcohol, opioids, benzodiazepines and other central nervous system depressants
- Additive sedation and impaired breathing and driving
- Ketoconazole (strong CYP3A4 inhibitor)
- Higher eszopiclone exposure
- Rifampicin
- Lower eszopiclone exposure
What is monitored
- Next-day alertness
- Unusual night-time behaviours
Administration and safety
- Given by mouth right before bed, only when a full night in bed is possible
- Lower dose in older adults
- Controlled medicine
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
Human data are not enough to define a risk; animal studies showed no malformations.
Test yourself
Think of the answer, then tap the question to see it.
What is eszopiclone chemically?
The S-enantiomer of racemic zopiclone.
Which adverse effect of eszopiclone affects taste?
An unpleasant, bitter taste.
Which two enzymes break down eszopiclone?
CYP3A4 and CYP2E1.
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: DailyMed - ESZOPICLONE tablet, film coated (DailyMed (U.S. National Library of Medicine), 2026); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026).
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Representative model, for educational purposes only.