It is limited in availability to prescription, and that only to those over 55 years old suffering from a sleeping disorder. So why is melatonin so popular? In one word — jetlag. It can be brutal, days or even weeks spent awake at 3 in the morning and fast asleep in the afternoon. Some frequent travellers obsess on specific routines to avoid increasing the likelihood of disturbed sleep, from proactively adjusting to the new time zone before arrival, to staying awake on a red-eye flight to sleep on arrival.
Across the Atlantic, the number of people in the US using melatonin has doubled, and over 3. While it is available in up to 10mg doses in the US as a dietary supplement, 5x the maximum available via a GP in the UK. The precursor to melatonin is serotonin, a primary neurotransmitter modulating mood balance, among other functions. Melatonin is produced in the pineal gland, in the middle of the brain, and it helps regulate day and night cycles.
Melatonin can help you fall asleep , albeit indirectly, studies indicate it can reduce insomnia if taken 90 minutes before bedtime. It is commonly used to reset the body clock when travelling long distances across time multiple time zones, as a short term solution for jet lag. Research suggests that the realised benefits improve the more time zones crossed, but less so for westward travel. Taking Melatonin supplements may help with certain situations and conditions, such as jet lag, delayed sleep-wake phase disorder, some sleep disorders in children and anxiety before and after surgery.
With the excitement of travelling comes jet lag if you have travelled particularly far. Jet lag effects many of us and it can leave us feeling irritable, have digestive problems and seriously disrupt our sleep.
The trek across multiple time zones mean your body is left incredibly confused and sleeping when you get home, or needing to stay awake for many more hours, feels completely unnatural and goes against every instinct in your body.
For those who suffer from DSWPD have an awfully hard time falling asleep at a usual time and waking up in the morning. On average, they would rather wake up between 10am and 1pm and have difficulty sleeping before 2am. The use of Melatonin on people with DSWPD has been extensively studied, with one trial consisting of people and lasting 4 weeks. The release of melatonin from the pineal gland is suppressed by ocular light at the retina. During a normal circadian cycle, melatonin reaches a peak concentration at approximately 2 — 3 am.
People who work night-shifts have a delayed peak in melatonin secretion, the degree of which is influenced by their level of night-light exposure and number of nights worked. The majority of the evidence relating to the therapeutic use of melatonin involves treating people with insomnia. This is because the nightly melatonin peak may be altered in people who report problems with the quality or quantity of their sleep.
There is evidence that melatonin can be effective in treating people with other forms of circadian disturbances, such as sleep disturbances in children or adolescents with neurodevelopmental disorders , the reduction or prevention of jet lag when taken at the right time and for sleep disturbances in people with vision abnormalities. Melatonin is available in modified and immediate-release formulations. Modified-release melatonin causes the blood concentration over time to more closely mimic a naturally occurring melatonin profile Figure 1.
Immediate-release melatonin results in a relatively rapid increase in melatonin levels. Figure 1 : Pharmacokinetics of immediate-release melatonin and modified-release melatonin. Adapted from Zisapel, 2. In New Zealand melatonin is a prescription only, unsubsidised medicine.
Therefore if prescribers are considering initiating melatonin treatment, modified-release melatonin is the only formulation that Medsafe has assessed as being safe, under the conditions set out in the Medicine Data Sheet. Generally, modified-release melatonin taken one to two hours before sleep onset is desired is a reasonable dosing regimen.
It is recommended that modified-release melatonin be taken with, or just after, food. Note that crushing or halving of tablets is not recommended by the manufacturer, as this alters the release profile of the medicine. However, if immediate-release melatonin is required, crushing of the approved modified-release formulation may be appropriate, e.
If the patient is unable to swallow tablets, modified-release melatonin tablets may need to be crushed or halved; careful halving of tablets may retain some of the delayed release profile. If a patient taking immediate-release melatonin would like to switch to modified-release melatonin, it is reasonable to take the same dose of modified-release melatonin one to two hours earlier than they had been taking the immediate-release formulation. The adverse effects associated with melatonin use are diverse but relatively uncommon.
The rate of adverse events in patients taking short courses of modified-release melatonin are reported to be similar compared with placebo, and include: asthenia weakness , headache, respiratory infections and back pain.
Melatonin is mainly metabolised by CYP1A enzymes therefore if it is taken concurrently with other substances that interact with this class of enzyme its metabolism may be affected. It should also be noted that children may have reduced CYP1A2 levels compared to adults, which in addition to the above potential drug interactions, may expose children to higher concentrations of melatonin than anticipated.
Whether or not medicines that affect the endogenous production of melatonin interact with melatonin taken orally is unknown. Melatonin may be preferable to zopiclone and benzo-diazepines for the short-term treatment of insomnia because it does not cause adverse effects such as excessive daytime sleepiness, vertigo and muscle weakness.
The safety of long-term melatonin use has not been widely studied and there are concerns that the long-term use of melatonin may have unforeseen consequences. The major safety concern with melatonin is what is not known about its long-term use, particularly among children and adolescents.
In animals that are seasonal breeders variations in melatonin production causes seasonally-appropriate changes, 17 e. A formulation of melatonin is used in some countries to enhance fertility in sheep. However, precocious puberty has been associated with abnormalities in melatonin rhythms and the possibility has been raised that the long-term use of melatonin in children may postpone the onset of puberty.
Melatonin receptors in arteries are known to be involved in thermoregulation. Dissatisfaction with sleep quality or distress from not sleeping will be experienced by most people at various times in their lives. Studies show that total sleep duration decreases by approximately ten minutes per decade of age, and cohorts of adults aged 55 years and older consistently report sleeping an average of seven hours per night. Primary insomnia can be diagnosed if a person has a significant sleep disturbance, occurring at least three nights per week, lasting for longer than one month, and there are no other contributing health conditions or sleep disorder diagnoses.
Patients with primary insomnia have long-term insomnia and one or more of the following symptoms: Due to age-related hormonal changes, insomnia is increasingly reported by people aged over 55 years.
Patients who report severe insomnia or who have insomnia that is not responding to treatment are likely to benefit from referral to a sleep specialist. When consulting with patients who report sleep problems, a detailed history is essential to establish patterns of insomnia, associated symptoms, as well as any underlying causal factors. People who experience insomnia are unable to sleep despite having sufficient time and desire to sleep.
In some people this desire to go to sleep produces a paradoxical alertness and arousal that counteracts somnolence. Insomnia may be due to one or a combination of four causes: external factors, medicines or substances, medical conditions and psychological disturbances Table 1.
The first-line treatment for insomnia should always be the elimination of any underlying causes of sleep disturbance before pharmacological treatment is considered. Sleep hygiene, stimulus control and sleep restriction treatment can be effective for people who are experiencing insomnia. Sleep hygiene refers to adopting behaviours and modifying environmental factors to increase the likelihood of sleep. Examples of sleep hygiene include ensuring light and temperature are conducive to sleep, avoiding heavy meals close to bedtime, limiting caffeine intake, restricting alcohol intake, avoiding smoking close to bedtime, avoiding napping during the day and avoiding vigorous exercise close to bedtime.
The objective of stimulus control is to retrain the patient to associate their bed and bedroom as a place of sleep and thereby establish a normal sleep-wake cycle.
This involves: Sleep restriction treatment involves the clinician calculating how many hours the patient spends in bed at night and then how many of these hours they are actually asleep. This is usually done with the use of a sleep diary.
The patient then restricts their time in bed to their calculated average sleep time, with a minimum time in bed of five hours. There is some evidence that bright light in the morning can be used to treat patients with insomnia with delayed sleep-onset, and bright light in the evening may be effective in treating insomnia associated with early morning waking. Modified-release, 2 mg melatonin tablets, once daily, one to two hours before bedtime is indicated for the treatment of primary insomnia in people aged over 55 years, for up to 13 weeks.
It is important that patients who are prescribed melatonin take the medicine as directed. If melatonin dosing occurs at times of the day other than when treatment is recommended sleep patterns could be disrupted even further. Patients may often enquire about the suitability of melatonin treatment for indications other than insomnia, e. Melatonin should not be prescribed in primary care to children with sleep disturbances who are otherwise healthy.
In general, melatonin treatment is only appropriate for children with neurodevelopmental disorders and sleep disturbances see below. In some situations it is not clear whether modified-release or immediate-release is the most effective treatment option as some studies do not specify which formulation of the medicine was used. Sleep disturbances are common in children with developmental disorders, e. These sleep disturbances are often long-term and harder to treat than in their age-matched peers.
Melatonin treatment for children with neurodevelopmental disorders and sleep disturbances is initiated by a specialist, e. A study that included children aged three to fifteen years with a history of impaired sleeping and a diagnosed neurodevelopmental disorder investigated whether immediate-release melatonin was beneficial in improving total sleep time and sleep onset.
Children were initiated on 0. In addition, given that lower doses of melatonin have been reported to be effective in other populations, e. Many experts would commence treatment with a 1 mg dose. Children with autism often secrete lower levels of melatonin compared with children in the general population.
A study including children aged between four and ten years, with a confirmed diagnosis of autistic disorder, compared the effectiveness of 3 mg, daily, modified-release melatonin treatment with cognitive behavioural therapy, or with both treatments combined.
Insufficient sleep and poor sleep hygiene are the most frequent reasons for sleep disturbances in teenagers. Adolescents naturally go to bed later and sleep later due to changes in lifestyle and changes in the timing of melatonin release.
Studies have shown that teenagers typically need at least 9 hours sleep a night, but often only manage 7. A meta-analysis of five trials found that melatonin could advance mean sleep onset by 40 minutes in patients with delayed sleep phase disorder. Most people experience jet lag when they travel across multiple time zones.
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