Objective: As a melatonin receptor agonist, ramelteon has been approved in the United States as a treatment for insomnia. As a potential alternation, ramelteon should be further evaluated in different doses and populations. This systematic review with meta-analysis aims to determine the efficacy and safety of ramelteon in the treatment of chronic insomnia.
Methods: We systematically searched and identified in Medline, Embase, PsycINFO and Cochrane Library until September 2011. We only included randomised controlled trials focused on ramelteon, vs. placebo, or any other treatment for patients with chronic insomnia. Data were extracted and evaluated by two independent investigators. If neither clinical nor statistical heterogeneity was found, we pooled results using a fixed-effect model.
Results: Eight studies were selected to include from 175 identified references. There were significant improvements in all the outcomes (subjective and polysomnographic sleep latency, total sleep time and latency to REM), except for the percentage of REM. By subgroup analysis, subjective sleep latency was reduced only in the patients of 18–64 years old, without in the patients over 65 years old. For the safety, ramelteon was not associated with higher risk ratio of any frequent adverse events comparing with control.
Conclusion: The efficacy and safety of ramelteon are promising for the chronic insomnia patients. More researches are required for robust conclusions, particularly well-designed; double-blind randomised controlled trials with higher doses of ramelteon (32 or 64 mg) for the older population comparing with other sedative hypnotics.