Safety and Efficacy of Lemborexant in Insomnia Patients: Results of a Postmarketing Observational Study of Dayvigo® Tablets

A prospective, postmarketing observational study was conducted to evaluate the safety and efficacy of lemborexant (LEM) tablets in daily clinical practice in Japan. No other studies of a similar size have been conducted since the marketing approval of LEM, making this the first report of its kind. Insomnia patients (n = 550) administered LEM (5–10 mg daily) for the first time were enrolled. Adverse events were collected for target events (somnolence, parasomnia, narcolepsy and associated conditions, suicidal ideation and suicidal behavior). Overall improvement of insomnia symptoms was assessed by the investigator based on the patient's complaint. Subjective sleep onset latency (sSOL) and subjective total sleep time (sTST) were investigated as sleep parameters. A case report form was obtained from 539 patients. The incidence of adverse drug reactions (ADRs) was 7.65% for somnolence, 1.76% for nightmares, 0.59% for abnormal dreams, and 0.20% for sleep paralysis. No serious ADRs or ADRs related to suicidal ideation or suicidal behavior were observed. The efficacy rate at the final evaluation was 80.83%. Decreased sSOL and increased sTST were observed as assessed starting from Week 8 of treatment. Based on the results of this study, the safety result was consistent with the safety profile described in the current package insert. Efficacy results also indicated that LEM is clinically useful.