13 Feb 2020

Nighttime wakefulness and wandering are common symptoms in Alzheimer’s disease, but doctors hesitate to prescribe sleep-enhancing drugs because those have been linked to worsening cognition and falls. Results from a Phase 3 trial published in the January Alzheimer’s & Dementia indicate that the orexin antagonist suvorexant is safe and increases nightly sleep time in people with mild to moderate AD. Alzforum reported these findings when Joseph Herring, Merck Research Laboratories, Kenilworth, New Jersey, presented them at the American Academy of Neurology’s annual meeting last year (May 2019 conference news). 

The U.S. Food and Drug Administration approved suvorexant, aka Belsomra, for insomnia in 2014, and recently added efficacy and safety data from the AD trial to its prescribing information. “This makes Belsomra the only insomnia drug with safety and efficacy data for use in mild to moderate Alzheimer’s disease in the label,” Herring wrote to Alzforum.

“The data will give physicians confidence that even in patients with dementia, it is worth trying the drug to help with sleep,” said David Holtzman, Washington University in St. Louis. 

The randomized, placebo-controlled trial included 285 people, average age 70, who suffered from both insomnia and mild or moderate Alzheimer’s. Half took the drug, the other half placebo, for four weeks. Treated individuals slept an average 28 minutes longer during the night than those on placebo. Suvorexant lessened nighttime waking after falling asleep by 15 minutes. Daytime drowsiness was more common in the treated group, but their cognition didn’t decline, at least over the four weeks of this study.—Gwyneth Dickey Zakaib