Night work: lemborexant shows no benefit over placebo in a small trial

A biological hypothesis that remains to be confirmed

Sleep difficulties among night workers may stem in part from a mismatch between their rest period and their circadian rhythm. Lemborexant blocks receptors for orexin, also called hypocretin, which is involved in maintaining wakefulness. This mechanism provides a rationale for testing the drug for daytime sleep, but does not guarantee its effectiveness in this setting.

What the researchers tested

The trial was randomized, double-blind and placebo-controlled. It included 29 night workers, 28 of whom were women, with a mean age of 37.2 years. After two weeks of baseline measurements, 15 participants received lemborexant and 14 received a placebo.

Treatment involved one week of dose adjustment, followed by two weeks at a dose of 5 or 10 mg in the lemborexant group. These doses describe the protocol studied, not a recommendation for use. The researchers measured sleep using diaries completed by participants and wrist actigraphy.

No demonstrated improvement over placebo

The analyses detected no significant difference between groups in daytime sleep duration with either measurement method. Nor did they show a specific improvement in sleep efficiency, subjective sleep quality or insomnia severity.

An exploratory analysis found more favorable self-reported sleep duration among participants whose dose was increased to 10 mg than among those who remained at 5 mg. But this result did not differ significantly from placebo. It therefore does not establish that the higher dose is effective or justify a dose increase.

A limited finding, including on safety

No serious adverse events were reported in the lemborexant group. With only 15 people exposed and a short follow-up period, this is not enough to establish the treatment’s safety for night workers.

The available abstract does not provide numerical differences between groups or their uncertainty intervals. It therefore does not allow a precise assessment of the magnitude of any potential effect. The large majority of women also limits the generalizability of the findings.

What we can take away

This pilot trial does not demonstrate that lemborexant improves daytime sleep in night workers compared with placebo. The exploratory dose-related signal needs confirmation, not conversion into treatment advice.