Improvement in self-reported, but not actigraphic, sleep measures with suvorexant in people with well-controlled Restless Legs Syndrome and persistent insomnia

Abstract

Background

Sleep disturbance remains common in people with Restless Legs Syndrome (RLS), even after RLS symptoms are sufficiently controlled with medication. We conducted a placebo-controlled crossover trial to examine the efficacy of suvorexant in improving sleep quality and quantity in people with well-controlled RLS and persistent insomnia.

Methods

In this double-blind, randomized, placebo-controlled crossover trial, 34 participants (70.6 % female, mean age = 62.7) with well-controlled RLS were randomized to placebo or suvorexant (10–20 mg) for 6 weeks, followed by a 2-week washout and then the opposite treatment. Study inclusion required an IRLS score <15, insomnia diagnosis per DSM-5, and a diary-reported combined Sleep Onset Latency (SOL) and Wake After Sleep Onset (WASO) > 45 min and a Total Sleep Time (TST) < 7 h on 7/14 baseline nights. The primary outcome was actigraphically-derived TST, and secondary outcomes were Insomnia Severity Index (ISI) score and actigraphically-derived WASO. Data for all sleep metrics were collected at baseline and for the last two weeks of each treatment period.

Results

There were no significant improvements in actigraphically-derived TST (p = 0.58) or WASO (p = 0.99) while taking suvorexant compared to placebo. However, there were significant reductions in insomnia symptoms, measured by the ISI, as well as increases in diary-reported TST (p = 0.01) while taking suvorexant compared to placebo. The most commonly reported side effect of suvorexant was fatigue (29.4 %).

Conclusions

We observed no significant differences between treatments in actigraphically-derived sleep measures, but support for suvorexant's benefit for overall insomnia and self-reported quantity of sleep in people with well-controlled RLS who continue to suffer from insomnia.

Clinical trials registration number

NCT04706091.