Suvorexant and Alzheimer's Insomnia: Four Trial Checks

A sleep-treatment appointment may involve both the person taking the medicine and someone who shares their home. Bring separate questions about nighttime waking, morning alertness and getting out of bed safely.

Check who the study included

The 2020 trial randomized 285 people with mild-to-moderate probable Alzheimer’s dementia and insomnia. Everyone needed an overnight co-resident trial partner; nursing-home residents were excluded. Treatment was suvorexant 10 mg, optionally increased to 20 mg, or placebo for four weeks.¹

The US BELSOMRA label covers insomnia involving difficulty falling or staying asleep. It does not indicate suvorexant as a treatment for Alzheimer’s disease. Narcolepsy is a contraindication.²

Separate extra sleep from cognitive protection

Sleep-laboratory recordings found an adjusted 28.2-minute greater increase in total sleep time with suvorexant than placebo at week four (95% confidence interval 11.1–45.2 minutes). Efficacy analyses included 135 versus 139 participants.¹

Cognitive and psychomotor tests detected no significant between-group differences. Four-week testing cannot establish long-term cognitive safety. Merck funded the trial; most authors had Merck employment ties.¹

Count people who fell, alongside sleep gains

Drowsiness (somnolence) occurred in 6/142 versus 2/143 participants. Four falls occurred in three suvorexant participants, versus none with placebo; one caused an ankle fracture. These counts do not establish causation.¹

The current label warns that drowsiness increases fall risk, particularly in older adults. Review getting up for the bathroom, walking aids and any previous falls with the prescriber.²

It requires at least seven hours before planned waking, advises avoiding alcohol and warns that other sedating medicines add to impairment. Sleepwalking or another complex sleep behavior requires immediate discontinuation; contact the prescriber promptly.²

Agree on a broader sleep plan

NICE’s³ dementia guidance in England advises considering a personalized plan combining sleep-hygiene education, daylight, exercise and activities suited to the person. This recommendation does not select suvorexant.³

Ask which changes to report, who will review them and when. Distinguish an observed awakening from a night when no one was awake to observe it.

The Notice It section of Did I Do That in My Sleep? explains that a partner can add a brief observation and that missing observations should remain blank. Follow the clinician’s instructions if a formal sleep diary is requested.