Suvorexant for the treatment of primary insomnia: A systematic review and meta-analysis.

Suvorexant is a dual orexin receptor agonist and is currently approved for the treatment of insomnia in the United States and Japan. We conducted a systematic review and meta-analysis to assess the efficacy and safety of suvorexant for the treatment of primary insomnia. We searched PubMed, EMBASE, and the Cochrane central register of controlled trials, contacted a relevant pharmaceutical company, and accessed websites of the U.S. Food and Drug Administration (FDA) and Pharmaceuticals and Medical Devices Agency (PMDA) for published and unpublished data. A total of four randomized trials involving 3076 patients with primary insomnia were included in our analysis. Our analysis suggested that suvorexant was associated with significant improvements in subjective time to sleep onset, subjective total sleep time, and subjective quality of sleep at 1 mo and 3 mo. Somnolence, fatigue, and abnormal dreams were the most common adverse effects. We concluded that suvorexant was associated with improvement in some sleep parameters and some adverse effects. To determine the place of suvorexant in the treatment of insomnia, comparative effectiveness trials are needed.