Adverse Drug Reactions

Clinical Trial Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. In controlled efficacy trials (Study 303 and Study 304), 1418 patients were exposed to lemborexant. In Study 303, 434 patients were treated with lemborexant for one year.

Adverse Reactions Resulting in Discontinuation of Treatment

The incidence of discontinuation due to adverse reactions for patients treated with 5 mg or 10 mg of lemborexant was 3.5% for 5 mg and 6.1% for 10 mg compared to 2.7% for placebo. The most common adverse reaction leading to discontinuation was somnolence (lemborexant 5 mg 1.1%, lemborexant 10 mg 2.3%, placebo 0.6%).

Most Common Adverse Reactions

In clinical trials of patients with insomnia treated with lemborexant 5 mg or 10 mg, the most common adverse reaction (reported in 5% or more of patients treated with lemborexant and at a higher rate than placebo) was somnolence (lemborexant 5 mg 6.6%, lemborexant 10 mg 10.5%, placebo 1.6%).

The majority of the adverse reactions of somnolence were mild in severity.

Table 1: Treatment-Emergent Adverse Reactions by Preferred Term and Decreasing Frequency – Incidence ≥2% in Any Lemborexant Treatment Group in Patients with Insomnia and Where the Incidence in the Lemborexant 10 mg Group Was More than Placebo from Study 303 and Study 304
Placebo Lemborexant
MedDRA Preferred Term (n=528)                               n (%) 5 mg                                       (n=580)                                      n (%) 10mg                                    (n=582)                                n (%)
Somnolence 9 (2.0) 38 (7.0) 61 (11.0)
Urinary tract infection 9 (2.0) 7 (1.0) 18 (3.0)
Fatigue 1 (0.2%) 14 (2.0) 12 (2.0)

Other Adverse Reactions

Sleep Paralysis

Sleep paralysis, an inability to move or speak for up to several minutes during sleep-wake transitions, can occur with the use of lemborexant. In clinical trials, lemborexant was associated with sleep paralysis: lemborexant 5 mg 1.1% or lemborexant 10 mg 1.6% compared to no reports for placebo.


Reporting of suspected adverse drug reactions
Please contact:
HI-Eisai Pharmaceutical, Inc.
+63 2 88875837 / +63 2 88875160 / +63 9088672236
Or Report to FDA Philippines: