Melatonin for insomnia; no products registered in Malaysia

Sleep is crucial for humans in order to achieve optimal cognitive function. Having enough sleep relaxes the body and plays a vital role in our ability to fight diseases, develop immunity, maintain metabolism, and fight chronic disease. For this purpose, an individual should get sufficient rest. Sleep quality can have an impact on a person's productivity as well as physical and mental function the following day. However, a portion of the population suffers from sleep-related disorders, also known as insomnia.

Signs, implications, and risk factors for insomnia

Individuals with insomnia have difficulty sleeping. A study published in the journal Nature and Science of Sleep in 2021 found that nearly 55 percent of all respondents get less than seven hours of sleep per night. A newspaper report mentioned that nine out of ten adults in Malaysia have sleep-related issues and sleep an average of 6.3 hours per day. This figure is the outcome of a study carried out in 2018 by an established data analysis company.

Slowed thinking, difficulty in concentrating, a lack of energy, and emotional disturbances are the effects of sleep deprivation. Insomnia can also increase the risk of obesity, hormonal imbalance, low immunity, mental illness, diabetes, and cardiovascular disease. Age, gender, environmental conditions, occupation, lifestyle, and levels of stress have all been identified as risk factors for insomnia.

The function of melatonin in the human sleep cycle

Melatonin is a hormone produced naturally in humans and plants. The pineal gland in the brain produces melatonin hormones, which are then released into the bloodstream. The production of this hormone coordinates the sleep-wake cycle between night and day. Melatonin facilitates the onset of sleep, which is induced by and promotes quality and consistent rest. Melatonin production decreases with age.

Melatonin can also be obtained from foods such as bananas, plums, grapes, rice, cereals, herbs, pineapples, oranges, and olive oil. When people consume melatonin-rich foods, their blood melatonin concentration might increase significantly.

Risks of taking unregistered melatonin products

In Malaysia, melatonin-containing medications are classified in Group C (First Schedule of the Poisons Act 1952), which allows registered and licenced pharmacists, doctors, dentists, and veterinarians to dispense melatonin products. To date, the Drug Control Authority, however, has not approved any melatonin products for use in Malaysia. In fact, several other nations, including the United Kingdom (UK), the European Union, Japan, Australia, and Canada, prohibit the use of melatonin-containing products even as over-the-counter medicines.

Due to its non-uniform content, such a product may have unfavourable consequences for the patient. For instance, products with excessive amounts of active constituents may have adverse effects on consumers. High melatonin doses might cause constipation, diarrhoea, anxiety, convulsions, and respiratory issues. Conversely, if the dose is too low, the product might not have the desired effect on the consumer.

Melatonin is also not suggested for pregnant women or people who are addicted to alcohol. Some medications, like fluvoxamine, carbamazepine, rifampin, warfarin, estrogen-containing hormones, and benzodiazepine or non-benzodiazepine sleep aids, might interact with melatonin-containing products. Therefore, melatonin is also not recommended for individuals taking these medications.

Advices for public

The public should be more cautious when purchasing or using melatonin-containing medications for insomnia because their use in Malaysia has not yet been approved. This also demonstrates that the products on the market, particularly those sold online, are not registered. The use of unregistered products seems to pose a risk to consumers.

As an alternative to melatonin products, the general public and, in particular, those with insomnia issues are encouraged to adopt healthy sleep practices (sleep hygiene). According to a recommendation from the American Academy of Sleep Medicine (AASM), every individual ought to commit to a consistent sleep schedule by waking up and going to bed at the same time every day, even on working leave. Furthermore, a sleep-friendly environment is encouraged, for example, by ensuring that the bedroom is peaceful, dark, cool, and comfortable for sleeping.

Also, at least 30 minutes prior to bedtime, all electronic devices and gadgets in the room should be turned off for a good night's sleep. Mobile phones, laptops, and televisions are a few of these gadgets. Additionally, when it is time to go to bed, it is best to avoid consuming huge portions of food, alcoholic beverages, or caffeine.

The following recommendation relates to physical activity. The public should be encouraged to move actively during the day, for instance, by exercising to make falling asleep at night easier. Smoking and watching television or playing video games until late at night should also be avoided because they can affect a person's circadian rhythm.

In conclusion, melatonin may be used to treat sleep-related issues like insomnia; however, its use has not yet been approved in Malaysia. Sleep habits and a healthy lifestyle are better options for improving sleep quality and managing insomnia. Also, if the insomnia persists, the patient should consult a doctor to seek proper advice.

If there are any inquiries regarding medicines, please call the National Pharmacy Call Centre at the toll-free number 1-800-88-6722 during weekdays from 8am to 5pm, except on public holidays.

Prepared by Siti Nurhidayah Zulzaki Hashim, a pharmacist from Klinik Kesihatan Port Dickson, Negeri Sembilan.