Ramelteon is mainly used for the treatment of insomnia with sleep onset difficulty. It regulates the sleep-wake cycle by mimicking endogenous melatonin.
What Are the Side Effects of Ramelteon?
Nervous System Reactions
Somnolence (5%).
Dizziness (5%).
Fatigue (4%).
Gastrointestinal Discomfort
Nausea (3%).
Diarrhea (2%).
Other Common Reactions
Headache (7%).
Upper respiratory tract infection (3%).
Dysgeusia (abnormal taste) (2%).
Myalgia (muscle pain) (2%).
Serious Side Effects of Ramelteon That Require Vigilance
Effects on the Endocrine System
Long-term use may lead to increased prolactin levels, manifested as amenorrhea, galactorrhea (nipple discharge), or decreased libido.
Psychiatric and Behavioral Abnormalities
May exacerbate undiagnosed mental illnesses (e.g., depression, suicidal ideation).
Rare cognitive and behavioral changes (e.g., sleepwalking, memory impairment).
Risks in Special Populations
Patients with hepatic impairment: Exposure to Ramelteon increases 10-fold in patients with moderate hepatic impairment; it is contraindicated in patients with severe hepatic impairment (Child-Pugh Class C).
Respiratory diseases: Although it does not exacerbate mild to moderate COPD (chronic obstructive pulmonary disease) or sleep apnea, data on severe cases is lacking.
Risk of Drug Interactions
Concurrent use with strong CYP1A2 inhibitors (e.g., fluvoxamine) can cause a 190-fold surge in Ramelteon’s blood concentration, which is an absolute contraindication.
Precautions for Taking Ramelteon
Administration Regimen
Standard dosage: Take 8mg 30 minutes before bedtime.
Dietary impact: High-fat meals increase the AUC (area under the concentration-time curve) by 31%, so concurrent intake with high-fat meals should be avoided.
Treatment duration recommendation: Use short-term (usually ≤ 35 days); long-term use requires monitoring of endocrine function.
Contraindicated Populations
Patients allergic to Ramelteon or its excipients.
Patients with severe hepatic insufficiency.
Patients currently taking fluvoxamine.
Pre-Treatment Evaluation
Screen for potential mental illnesses and respiratory diseases.
Liver function tests (dosage reduction is required for patients with moderate hepatic impairment).
Monitoring During Treatment
When female patients experience menstrual abnormalities or galactorrhea, prolactin levels should be tested.
Monitor changes in mood (especially in patients with depression).
Safety Warnings
Go to bed immediately after taking the medication; avoid nighttime activities.
Avoid alcohol consumption (may enhance central nervous system depressant effects).

