Efficacy and safety of melatonin for the treatment of primary insomnia

ABSTRACT

Strength of recommendations: Weak in favor of Melatonin

Technology: Melatonin

Indication: Primary insomnia treatment

Characterization of the technology: Capsules or tablets, used for primary insomnia treatment

Question: Is Melatonin (MLT) effective for the treatment of primary insomnia?

Search and analysis of scientific evidence: We searched the Medline (via Pubmed), The Cochrane Library (via Bireme), Lilacs and the Centre for Reviews Dissemination (CRD). Systematic Reviews (SR) of randomized controlled clinical trials comparing Melatonin or Ramelteon to placebo were included. The quality of evidence and strength ofrecommendation were assessed using the GRADE system.

Summary of results of selected studies: 3 SR were selected which presented from low to moderated quality. The strength of recommendation for 2 of the 3 studies was weak in favor of MLT. The use it was associated with significant reduction of sleep latency. Total sleep time and sleep quality showed mixed results between nonsignificant and significant difference favoring the test drug when compared to placebo across studies. Melatonin showed little to none adverse effects.

Recommendations: We weakly recommended the use of melatonin, considering that SR and Health Technology Assessment included in this advice demonstrated for patients with primary insomnia, melatonin showed statistically significant efficacy in reducing the time of sleep latency compared to placebo. For other outcomes evaluated – quality of sleep and total sleep time – the results were inconclusive, ranging from no significant difference to statistically significant. Regarding the safety profile, the studies found no adverse effects, but it should be noted that monitoring occurred only for short term use.

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