Warning issued against using melatonin for sleep disorders
Melatonin is a hormone made by the pineal gland camera.gif, a small gland in the brain. Melatonin helps control your sleep and wake cycles. Very small amounts of it are found in foods such as meats, grains, fruits, and vegetables. It can be purchased as a supplement.
Melatonin is being increasingly prescribed for children with sleep disorders. In a published paper Professor David Kennaway, PhD, Head of the Circadian Physiology Laboratory at the University of Adelaide’s Robinson Research Institute, warns that providing melatonin supplements to children may result in serious side effects when the children are older.
According to Professor Kenna way, “The use of melatonin as a drug for the treatment of sleep disorders for children is increasing and this is rather alarming.”
Professor Kennaway says the United States is the only country where melatonin is completely unregulated. “It’s considered to be a ‘dietary supplement’, not a regulated drug, and is therefore readily available,” he says.
“In Australia, melatonin is registered as a treatment for primary insomnia only for people aged 55 years and over, but it’s easily prescribed as an ‘off label’ treatment for sleep disorders for children.”
The problems with melatonin is 1) it is not registered for use in children anywhere in the world, 2) it has not undergone the formal safety testing expected for a new drug, especially long-term safety in children, 3) it is known to have profound effects on the reproductive systems of rodents, sheep and primates, as well as effects on the cardiovascular, immune and metabolic systems and 4) there is the potential for important interactions with drugs sometimes prescribed for children.
In this review Professor Kennaway discusses the properties of melatonin outside its ability to alter sleep timing that have been widely ignored but which raise questions about the safety of its use in infants and adolescents.
Professor Kennaway says there is extensive evidence from laboratory studies that melatonin causes changes in multiple physiological systems, including cardiovascular, immune and metabolic systems, as well as reproduction in animals.
“Melatonin is also a registered veterinary drug which is used for changing the seasonal patterns of sheep and goats, so they are more productive for industry. If doctors told parents that information before prescribing the drug to their children, I’m sure most would think twice about giving it to their child,” he said.
“The word ‘safe’ is used very freely and loosely with this drug, but there have been no rigorous, long-term safety studies of the use of melatonin to treat sleep disorders in children and adolescents.
“There is also the potential for melatonin to interact with other drugs commonly prescribed for children, but it’s difficult to know without clinical trials assessing its safety.”
Professor Kennaway, who has been researching melatonin for the past 40 years, says these concerns have largely been ignored throughout the world.
“Considering the small advances melatonin provides to the timing of sleep, and considering what we know about how melatonin works in the body, it is not worth the risk to child and adolescent safety,” he says.
Potential safety issues in the use of the hormone melatonin in paediatrics. Journal of Paediatrics and Child Health, 2015; DOI: 10.1111/jpc.12840
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