Complementary, Holistic, and Integrative Medicine: Melatonin

Abstract

1. Larissa Shamseer* 2. Sunita Vohra, MD, MSc* 1. *Complementary and Alternative Research and Education (CARE) Program, Department of Pediatrics, Faculty of Medicine, University of Alberta. On behalf of the American Academy of Pediatrics Section on Complementary and Integrative Medicine Melatonin is synthesized primarily in the pineal gland, although it also can be produced in the retina and gastrointestinal tract. Melatonin helps regulate circadian rhythms, specifically sleep-wake cycles. These cycles are under the control of the suprachiasmatic nucleus, through which patterns of light and darkness are transferred from the retina to the pineal gland. Melatonin is formed from the essential amino acid tryptophan via serotonin, based on specific patterns. Simply stated, in the presence of light, melatonin production is inhibited; in the darkness, it is synthesized. Melatonin also can be taken as an exogenous supplement, which is synthesized to be chemically identical to its endogenous counterpart, and is classified as a natural health product by Health Canada or dietary supplement by the United States Food and Drug Administration. Due to its involvement in the sleep cycle, exogenous melatonin has been investigated extensively for sleep disorders. Difficulties initiating and maintaining sleep affect 15% to 25% of the pediatric population. Thirty minutes is believed to be the normal time to initiate sleep or sleep onset latency (SOL), which is defined as the amount of time between the person laying down to sleep and the onset of stage 1 sleep. (1)(2)(3)(4) A difference of 15 minutes in SOL typically is considered clinically important. (4) The literature evaluating melatonin for the treatment of sleep disorders was reviewed systematically in 2004 by the Agency for Healthcare Research and Quality (AHRQ). (5) Efficacy reports of melatonin for primary and secondary sleep disorders, including examination of pediatric subgroups, appeared in subsequent publications following the AHRQ report. Findings indicate that melatonin may be safe and effective for managing some primary (Table 1) and secondary (Table 2) sleep disorders. | Author and Year | Study Design | Population | Intervention/Control | Dose/Frequency/Duration | Outcome | |:----------------:| ------------ | -------------------------------------------------- | ------------------------- | ----------------------------------------------------- | ----------------------------------------------- | | Buscemi 2005 (6) | SR | N: 2 RCTs; 110 participants | I: Fast-release melatonin | 5 mg/once per day before bedtime/4 weeks of treatment | Reduction in SOL: 16.7 min (95% CI −29.4, −4.0) | | | | Age: 0 to 18 years | C: Identical placebo | | | | Condition: idiopathic chronic sleep-onset insomnia | | | * CI=confidence interval, RCT=randomized, controlled trial, SOL=sleep-onset latency, SR=systematic review Table 1. Study of Melatonin in …