
Ramelteon is a selective MT1/MT2 melatonin receptor agonist, indicated for the treatment of insomnia characterized by difficulty falling asleep.
How to Use Ramelteon
Standard Dosing Regimen
Dosage: The recommended dose is 8 mg, to be taken orally within 30 minutes before bedtime.
Dosage Form: 8 mg film-coated tablets, containing excipients such as lactose and starch; the tablets should be swallowed whole.
Timing of Administration: Administration with a high-fat meal should be avoided (as this can increase AUC by 31% and decrease Cmax by 22%).
Operational Precautions
Missed Dose Handling: If a dose is missed, it should be taken as soon as possible before bedtime, and the original scheduled dosing time should be resumed the next day.
Contraindicated Combinations: Concomitant use with potent CYP1A2 inhibitors (e.g., fluvoxamine) is contraindicated (as this can increase AUC by 190-fold).
Precautions for Ramelteon Use
Dosage Adjustments in Patients with Hepatic Impairment
Mild Hepatic Impairment: No dosage adjustment is required, but careful monitoring is necessary.
Moderate Hepatic Impairment: Use with caution (exposure may increase by more than 10-fold).
Severe Hepatic Impairment (Child-Pugh Class C): Contraindicated.
Management of Adverse Reactions
Common Reactions: Drowsiness (5%), dizziness (5%), and fatigue (4%); usually, no discontinuation of treatment is needed.
Endocrine Effects: Long-term use may increase prolactin levels (with an average increase of 34% in women); attention should be paid to symptoms such as menstrual abnormalities or galactorrhea.
Severe Reactions: If signs of allergy or liver injury (e.g., jaundice, elevated transaminases) occur, treatment should be discontinued immediately.
Drug Interactions
Enzyme Inducers (e.g., rifampicin): May reduce the efficacy of ramelteon; alternative treatment options should be evaluated.
Central Nervous System (CNS) Depressants (e.g., alcohol): May enhance sedative effects; concomitant use should be avoided.
Ramelteon Use in Special Populations
Elderly Patients
Dosage: Same as that for adults (8 mg), but note that AUC may increase by 97% (especially in patients aged ≥ 75 years).
Monitoring: Pay attention to residual effects the next day (e.g., fatigue, memory impairment).
Pregnant and Lactating Women
Pregnancy: Animal studies have shown a teratogenic risk (diaphragmatic hernia at doses ≥ 150 mg/kg); data in humans are limited. Use is only recommended when the potential benefit is significant.
Lactation: Ramelteon is excreted in rat milk; excretion in human milk is unknown. It is recommended to discontinue the drug or stop breastfeeding.
Patients with Respiratory Diseases
Mild to Moderate COPD/Sleep Apnea: May be used, but data on severe cases are lacking.
Severe Sleep Apnea: Use is not recommended.