Pharmacology · Other hypnotics (melatonin agonists and orexin antagonists)
Ramelteon !
A melatonin receptor agonist for trouble falling asleep. It does not act on GABA, is not a controlled substance and shows no abuse potential.
Updated 2026-11-01
The figure shows ramelteon itself bound to the human MT1 melatonin receptor.
Mechanism of action
Ramelteon binds MT1 and MT2 melatonin receptors with high affinity and stimulates them, imitating the night signal of melatonin in the brain's clock. It has no appreciable affinity for the GABA receptor complex.
- Binds MT1 and MT2 melatonin receptors
- Imitates melatonin's night signal
- Sleep onset comes sooner
Pharmacokinetics
- Absorption
- Not taken with or right after a high-fat meal
- Metabolism
- Mainly by CYP1A2, with minor CYP2C and CYP3A4
- Half-life
- About 1 to 2.6 hours
Indications
- Insomnia with difficulty falling asleep Insomnia disorder →
Adverse effects
Common
- Drowsiness and tiredness
- Dizziness
- Nausea and worsened insomnia
Contraindications
- Previous angioedema with ramelteon
- Use with fluvoxamine
Key interactions
- Fluvoxamine (strong CYP1A2 inhibitor)
- Much higher ramelteon levels: contraindicated
- Alcohol
- Added sedation
What is monitored
- Sleep onset
- Unexplained missed periods, milk discharge, low libido or fertility problems: prolactin and testosterone may be checked
Administration and safety
- Given by mouth shortly before bed
- Not with or right after a high-fat meal
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
Post-marketing reports have not shown a clear risk of major birth defects; animal studies showed harm at high exposures.
Test yourself
Think of the answer, then tap the question to see it.
Is ramelteon a controlled substance?
No; it shows no abuse potential or physical dependence.
Which enzyme mainly breaks down ramelteon?
CYP1A2, which is why fluvoxamine is contraindicated.
Which hormonal changes are linked to ramelteon?
Lower testosterone and higher prolactin.
Related drugs
Related conditions
← Back to the class: Other hypnotics (melatonin agonists and orexin antagonists)
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 - RAMELTEON tablet, film coated (DailyMed (U.S. National Library of Medicine), 2026); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026); 6ME2: XFEL crystal structure of human melatonin receptor MT1 in complex with ramelteon (RCSB Protein Data Bank, 2019).
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Representative model, for educational purposes only.