Don’t think of melatonin as a magic medicine for insomnia

This is the 3910th article of Da Yi Xiao Hu

Once upon a time, melatonin was popular all over the country as a miracle drug. Many insomnia patients even regarded it as a miracle drug for insomnia. They would take a pill whenever they had insomnia. In fact, melatonin is only suitable for insomnia caused by certain reasons. Today we will talk about how to correctly understand the application of melatonin in sleep disorders.

1. Where does melatonin come from? What are its physiological effects?

Melatonin is a hormone secreted by a structure in the brain called the pineal gland. As an important endogenous timing factor, its synthesis and rhythm are controlled by the light cycle. In other words, melatonin is the intermediary between light and the biological clock, and has the function of regulating the sleep-wake cycle and improving jet lag syndrome.

2. What kind of sleep disorders is melatonin suitable for clinically?

Usually, clinically, scheduled melatonin is used to treat sleep disorders caused by sleep-wake cycle disorders, that is, giving melatonin in the morning can delay the circadian rhythm, and giving melatonin in the afternoon or evening can advance the circadian rhythm, corresponding to the treatment of patients with delayed sleep-wake phase disorder and advanced sleep-wake phase disorder, which correspond to what we usually call night owls and early risers. However, there is one issue that needs attention. Small doses of melatonin may change the circadian rhythm, while large doses have a sedative and hypnotic effect. In addition, patients may return to their previous sleep-wake cycle 2-3 days after stopping the drug. At the same time, melatonin can also cause hypothermia, inhibit gonadal development, release excessive prolactin to cause infertility and reduce sexual desire, so it is not suitable for long-term and large-scale use.

3. Can melatonin be used to treat insomnia?

In clinical practice, melatonin sustained-release agents are suitable for patients aged ≥55 years, and are mainly used for short-term treatment of insomnia with difficulty maintaining sleep. Another major category of drugs is melatonin receptor agonists, the most common of which are ramelteon and agomelatine. Ramelteon is indicated for insomnia with initial difficulty sleeping, and can also be used for insomnia with circadian rhythm disorders and sleep disorders caused by jet lag. It may not be effective for early awakening. Common adverse reactions include sleepiness, dizziness, nausea, fatigue, and headache. It should not be used in patients with severe liver damage and patients taking fluvoxamine at the same time. It should also be used with caution in patients with severe obstructive sleep apnea. Agomelatine has the effects of anti-depression, anti-anxiety, and regulating sleep rhythm and biological clock. It is suitable for treating anxiety and insomnia symptoms in patients with depression. Adverse reactions include dizziness, drowsiness, etc. Avoid driving and mechanical operation during use.

Knowing these little-known facts about melatonin, will you still use melatonin to treat insomnia? Different types of insomnia should choose appropriate anti-insomnia drugs. At the same time, non-drug treatments such as cognitive behavioral therapy can effectively improve insomnia symptoms. Don't use melatonin as a miracle drug!

Author: Jilin University Second Hospital

Department of NeurologyMan YuhongChief Physician