Randomized Trial Shows Lemborexant Does Not Improve Daytime Sleep for Night Shift Workers

A recent randomized controlled trial led by researchers from the University of California, San Francisco, and published in the Journal of Clinical Sleep Medicine, investigated the effects of the sleep medication lemborexant on daytime sleep for night shift workers. Night shift workers, including nurses and security guards, often struggle to obtain sufficient daytime rest, a challenge that can adversely affect health and safety.

Lemborexant belongs to a new class of medications called dual orexin receptor antagonists (DORAs), which target the body's wakefulness signals more precisely than traditional sedatives. The premise is that by blocking neuropeptides hypocretin and orexin, which promote alertness, these medications might help shift workers sleep during the day, when biological forces typically make it difficult.

The study involved 29 night shift workers with a mean age of 37.2 years, predominantly female. Participants underwent a baseline period to measure their typical daytime sleep before receiving either 5 mg of lemborexant or a placebo for one week. A two-week maintenance phase followed, in which some participants increased to 10 mg while others continued on 5 mg or placebo. The study was double-blind, ensuring neither participant nor investigator knew who received the active drug, and was registered at ClinicalTrials.gov under the identifier NCT05344443.

Results indicated no significant differences in total daytime sleep duration between the lemborexant and placebo groups, whether analyzed through sleep diaries or actigraphy. Additionally, sleep efficiency and subjective sleep quality did not show improvement with lemborexant. Even validated assessments of insomnia severity did not reveal a decline that favored the medication over placebo.

However, among participants receiving the higher 10 mg dose, exploratory analyses suggested a statistically significant improvement in sleep duration compared to those on 5 mg, though this did not reach significance against the placebo. This finding hints that the dosing of orexin blockade may be crucial and that the lower starting dose might have been insufficient to aid daytime sleep.

Safety data indicated no severe adverse events among those taking lemborexant, aligning with its established safety profile in insomnia treatment. This is significant given the risks associated with older sleep medications, such as dependence and cognitive impairment.

The implications of this trial extend beyond individual health; shift work disorder affects a substantial number of night shift workers, leading to increased risks of cardiovascular disease and occupational errors. Given that one in five workers in industrialized countries operates outside standard hours, effective pharmacological options could yield public health benefits.

Despite the absence of improvement from lemborexant in this trial, researchers emphasized the need for further exploration into optimal dosing and broader participant demographics. The small sample size and overwhelming majority of female participants could limit the findings’ generalizability, while the two-week maintenance phase might have been too brief to observe the full effects.

For now, clinicians are advised to manage expectations regarding lemborexant's effectiveness for nighttime workers. The results highlight that promising biological mechanisms do not always translate into clinical outcomes. Until further research can provide clarity, night shift workers should continue utilizing non-pharmacological strategies like light exposure and consistent sleep schedules to enhance daytime rest.