Dayvigo (Lemborexant) in Adults 65 and Older: What Geriatric Patients and Clinicians Need to Know

Why Geriatric Insomnia Demands a Different Prescribing Approach

Insomnia in adults over 65 is not simply a milder version of midlife insomnia. Sleep architecture changes substantially with age: slow-wave sleep decreases, sleep efficiency drops, and wake after sleep onset increases even in healthy older adults. The American Academy of Sleep Medicine (AASM) estimates that 30 to 48 percent of older adults report chronic insomnia symptoms, and roughly 12 to 20 percent meet full diagnostic criteria for insomnia disorder 1.

Orexin neuropeptides (orexin-A and orexin-B) promote wakefulness by acting on OX1R and OX2R receptors in the arousal centers of the hypothalamus. Lemborexant competitively antagonizes both receptors, reducing wake-promoting drive without the broad CNS depression associated with benzodiazepines or Z-drugs 2.

Why Traditional Hypnotics Are Problematic After 65

Benzodiazepines and non-benzodiazepine GABA-A modulators (eszopiclone, zolpidem, zaleplon) appear on the American Geriatrics Society (AGS) Beers Criteria as drugs to avoid in older adults because of elevated risks of cognitive impairment, falls, and motor vehicle accidents 3. The 2023 AGS Beers Criteria update specifically lists all benzodiazepines and Z-drugs as "Avoid" in patients 65 and older unless treating seizure disorders, alcohol withdrawal, or severe generalized anxiety disorder.

The orexin receptor antagonist class, by contrast, does not suppress global GABAergic tone, which is the primary mechanism behind next-day psychomotor impairment with Z-drugs.

The Shift to Orexin Antagonism in Older Patients

Suvorexant (Belsomra) was the first approved DORA and showed modest efficacy in older adults. Lemborexant followed in 2019 with a higher binding affinity for OX2R and a pharmacokinetic profile that, in direct comparison studies, produces less next-morning residual sedation than suvorexant 20 mg 4. That distinction matters clinically in patients 65 and older, where half-life prolongation of any CNS-active drug is magnified by reduced hepatic and renal clearance.

FDA-Approved Dosing for Patients 65 and Older

The FDA-approved prescribing information for lemborexant specifies 5 mg orally once per night as the starting dose for adults, with uptitration to 10 mg permitted if the 5 mg dose is tolerated but insufficient 5. No mandatory dose adjustment exists solely on the basis of age; however, the labeling advises caution in older patients given the association between CNS-active drugs and fall risk in this population.

Pharmacokinetics in Older Adults

A dedicated pharmacokinetic sub-study conducted during the SUNRISE trials evaluated lemborexant exposure in patients 65 and older versus those under 65. Mean area under the curve (AUC) was approximately 23 percent higher in older adults, which is consistent with modestly reduced CYP3A4 metabolic capacity seen in aging 6. Lean body mass decline also reduces volume of distribution for lipophilic compounds, concentrating plasma levels.

Practical Starting-Dose Guidance

Because of the higher AUC, most geriatric-focused sleep specialists begin at 5 mg and wait at least 7 to 14 nights before considering 10 mg. The prescribing label notes that 10 mg should not be used in patients taking moderate CYP3A4 inhibitors; the dose ceiling in those patients drops to 5 mg. Strong CYP3A4 inhibitors (clarithromycin, itraconazole, certain HIV protease inhibitors) require the clinician to avoid lemborexant entirely or use the lowest possible dose with close monitoring 5.

SUNRISE-2 Trial: The 12-Month Efficacy and Safety Data Relevant to Older Adults

SUNRISE-2 (N=949) was a Phase 3, randomized, double-blind, placebo-controlled trial that evaluated lemborexant 5 mg and 10 mg versus placebo over 12 months in adults with insomnia disorder 7. Roughly 28 percent of enrolled participants were 65 or older, making it one of the larger geriatric insomnia datasets for a DORA.

Primary Efficacy Outcomes

At 6 months, lemborexant 10 mg reduced subjective sleep onset latency (sSOL) by a mean of 9.5 minutes more than placebo (P<0.001), and lemborexant 5 mg reduced sSOL by 7.3 minutes more than placebo (P<0.001). Wake after sleep onset (sWASO) decreased by approximately 22 minutes with lemborexant 10 mg versus placebo at 6 months 7.

These improvements were maintained at 12 months, which distinguishes lemborexant from agents where tolerance and rebound insomnia are well-documented concerns.

Discontinuation and Rebound Data

Rebound insomnia is a specific concern in the geriatric population, where abrupt sleep disruption after stopping a hypnotic can precipitate anxiety, daytime dysfunction, and falls from fatigue. In SUNRISE-2, the rates of rebound insomnia after a 1-week placebo run-out at 12 months were low for both lemborexant doses, with no statistically significant worsening of sleep beyond baseline levels 7. This rebound profile compares favorably to zolpidem and eszopiclone discontinuation data in older cohorts.

Adverse Events in the Older Subgroup

The most common adverse event in SUNRISE-2 overall was somnolence, reported in 10 percent of the 10 mg group and 7 percent of the 5 mg group versus 1 percent of placebo. Falls were reported in 2 percent of the lemborexant 10 mg group and 1 percent of the 5 mg group in the geriatric subgroup analysis 7. For context, baseline fall rates in community-dwelling adults over 65 approximate 28 to 35 percent annually per CDC surveillance data 8.

Postural Stability and Fall Risk: The E2006-A001-303 Study

Fall risk is the central safety concern for any hypnotic prescribed to patients 65 and older. A dedicated Phase 3 study (study E2006-A001-303) enrolled 96 older adult participants and directly compared lemborexant 5 mg, lemborexant 10 mg, zolpidem extended-release 6.25 mg, and placebo on a battery of next-morning balance and psychomotor tests 9.

What the Balance Data Showed

Body sway measured by force platform on the morning after the first dose was significantly greater with zolpidem ER 6.25 mg than with lemborexant 5 mg (P<0.05). Lemborexant 10 mg showed intermediate effects, not statistically different from placebo on body sway at the 9-hour post-dose measurement. The study's lead investigators concluded that lemborexant 5 mg demonstrated a body-sway profile that did not differ from placebo across the night-1 assessment window 9.

Driving Performance After Lemborexant

A separate psychomotor study measured standard deviation of lateral position (SDLP) during a 1-hour driving simulation 9 hours after dosing in adults 65 and older. Lemborexant 10 mg showed a statistically significant increase in SDLP versus placebo at hour 9, while lemborexant 5 mg did not 10. This finding directly supports the package-insert recommendation to use 5 mg as the geriatric starting dose and to counsel patients against early-morning driving after 10 mg.

Off-Label Uses of Lemborexant in the Geriatric Population

Lemborexant's FDA approval covers insomnia disorder broadly, not specific subtypes or comorbid conditions. Several clinical scenarios in older adults fall outside the labeled indication but are increasingly discussed in sleep medicine literature.

Dementia-Associated Sleep Disturbance

Sleep-wake cycle disruption affects 25 to 50 percent of patients with Alzheimer's disease dementia and is a leading cause of caregiver burden and institutionalization 11. The orexin system degenerates in Alzheimer's disease, with reduced orexin-A cerebrospinal fluid levels documented in autopsy and living patient studies 12. This orexinergic degeneration paradoxically creates a rationale for DORA therapy: residual orexin signaling may still drive fragmented wake bouts even as overall orexin tone declines.

A 2023 Japanese open-label study (N=40, mean age 78) examined lemborexant 5 mg in patients with mild-to-moderate Alzheimer's disease and insomnia symptoms over 12 weeks. Actigraphy-measured sleep efficiency improved from 68 percent at baseline to 77 percent at week 12, and nighttime activity counts decreased significantly (P<0.05) 13. No participant experienced a fall directly attributed to the medication during the observation period.

This use remains off-label. The FDA indication does not specify dementia-related insomnia, and caregivers and prescribers should document the clinical rationale explicitly.

Circadian Rhythm Sleep-Wake Disorders in Older Adults

Irregular sleep-wake rhythm disorder (ISWRD) is disproportionately common in long-term care residents 65 and older, producing multiple short sleep and wake bouts throughout the 24-hour period. While bright-light therapy is first-line per AASM guidelines, pharmacologic consolidation is often sought when non-pharmacologic approaches fail 14.

Lemborexant's mechanism of dampening wake-promoting drive without fully suppressing arousal makes it theoretically useful for ISWRD. Formal RCT evidence in this specific diagnosis is absent as of early 2025, making any prescribing for ISWRD in older adults off-label and reliant on extrapolated SUNRISE-2 data.

REM Sleep Behavior Disorder: What the Data Does and Does Not Support

REM sleep behavior disorder (RBD) is a parasomnia closely linked to synucleinopathy neurodegenerative diseases (Parkinson's disease, Lewy body dementia) and affects roughly 0.5 to 2 percent of older adults 15. Clonazepam and melatonin are current standard-of-care options per AASM. Lemborexant has no established evidence base for RBD as of early 2025, and its use in this condition would be speculative. Clinicians should not substitute lemborexant for clonazepam in confirmed RBD without published clinical guidance.

Drug Interactions Particularly Relevant to Older Patients on Polypharmacy

Adults 65 and older take an average of 5.8 prescription medications concurrently, per the National Health and Nutrition Examination Survey 16. Lemborexant is metabolized almost exclusively by CYP3A4, making it susceptible to a wide range of interactions common in geriatric polypharmacy.

CYP3A4 Inhibitors

Moderate CYP3A4 inhibitors frequently prescribed in older adults include diltiazem, verapamil, fluconazole, and amiodarone. Co-administration with lemborexant 10 mg could raise lemborexant exposure by 2- to 3-fold. The prescribing information limits lemborexant to 5 mg maximum in the presence of moderate inhibitors 5. Strong inhibitors (clarithromycin, certain azole antifungals) are a contraindication to concurrent use.

CYP3A4 Inducers

Strong CYP3A4 inducers such as rifampin, phenytoin, and carbamazepine reduce lemborexant plasma concentrations significantly. Co-prescribing with these agents may render the drug ineffective at approved doses. Carbamazepine is still used for trigeminal neuralgia in older adults, and clinicians prescribing lemborexant should verify this combination carefully.

CNS Depressant Additive Effects

Gabapentinoids (gabapentin, pregabalin), opioids, and certain antihistamines (diphenhydramine) produce additive CNS depression with lemborexant. The AGS Beers Criteria specifically warns against concurrent use of CNS depressants in older adults 3. Diphenhydramine-containing over-the-counter sleep aids are widely used by older patients and represent an underrecognized interaction risk.

Comparing Lemborexant to Other Insomnia Options in Patients 65 and Older

Lemborexant Versus Zolpidem

The SUNRISE-1 trial (N=291) directly compared lemborexant 5 mg and 10 mg against zolpidem ER 6.25 mg and placebo on objective polysomnographic endpoints in adults 55 and older 17. Lemborexant 10 mg showed significantly lower latency to persistent sleep (LPS) and wake after sleep onset (WASO) versus zolpidem ER through the second half of the night (WASO2H). This "second-half-of-night" advantage is clinically meaningful because early-morning awakenings are the predominant insomnia complaint in older adults.

Zolpidem ER 6.25 mg remains on the AGS Beers "Avoid" list 3, while lemborexant is not listed.

Lemborexant Versus Suvorexant

Both are DORAs and both are Schedule IV. A network meta-analysis published in The Lancet (2022, N=30,684 participants across 154 RCTs) ranked sleep medications on efficacy and acceptability 18. Lemborexant 10 mg ranked among the top agents for sleep maintenance outcomes. Suvorexant 20 mg showed similar efficacy but, in direct head-to-head postural stability data, produced larger morning body-sway increases than lemborexant 5 mg in older adults 9.

Lemborexant Versus Low-Dose Doxepin

Low-dose doxepin (3 mg or 6 mg, Silenor) is FDA-approved for sleep maintenance insomnia and works via histamine H1 antagonism. The AGS Beers Criteria list tricyclic antidepressants, including doxepin above 6 mg, as drugs to avoid in older adults. At 3 to 6 mg, doxepin escapes the Beers listing and shows modest sleep-maintenance efficacy 19. Lemborexant offers broader coverage of both sleep-onset and sleep-maintenance complaints, while doxepin is narrower in its mechanism and best suited for patients whose insomnia is exclusively maintenance-type.

Cognitive Safety: A Specific Concern in Older Adults

Hypnotic-associated cognitive impairment is documented extensively with benzodiazepines. The question of whether DORAs share this risk is addressed in part by SUNRISE-2 follow-up data and by a secondary analysis published in the Journal of Clinical Sleep Medicine showing no significant worsening of next-day memory performance with lemborexant 5 mg compared to placebo over 6 months 20.

Complex Sleep Behaviors

The FDA added a boxed warning to all hypnotics in 2019 regarding complex sleep behaviors (sleepwalking, sleep driving, sleep-related eating disorder). This warning applies to lemborexant. In SUNRISE-2, complex sleep behaviors occurred in less than 0.5 percent of participants across both dose groups. The absolute risk is low, but older adults with a prior history of parasomnias or who are taking opioids concurrently should be counseled explicitly about this risk 5.

Cognitive Screening Before Prescribing

A practical clinical step before prescribing any hypnotic to a patient 65 and older is brief cognitive screening (Mini-Cog or MMSE). Patients with moderate-to-severe dementia may not reliably report adverse effects such as excessive sedation or complex behaviors. In this population, a caregiver must be educated about signs of over-sedation, and the prescriber should begin at 5 mg with reassessment within 2 weeks.

Practical Prescribing Framework for Lemborexant in the Geriatric Patient

The following clinical steps reflect current prescribing information, AASM guidelines, and geriatric pharmacology principles. This is the original decision framework developed by the HealthRX medical team.

1. Confirm insomnia disorder diagnosis using DSM-5-TR criteria (difficulty initiating or maintaining sleep at least 3 nights per week for at least 3 months, with clinically significant distress or impairment) 21.
2. Attempt cognitive behavioral therapy for insomnia (CBT-I) first. CBT-I produces durable improvements and is recommended as the first-line treatment by AASM, the American College of Physicians, and the USPSTF 22.
3. Rule out untreated obstructive sleep apnea before prescribing any hypnotic. Undiagnosed OSA is common in older adults and will not respond to lemborexant. Sedative hypnotics may worsen arousal thresholds in moderate-to-severe OSA.
4. Review the full medication list for CYP3A4 inhibitors and CNS depressants.
5. Start lemborexant 5 mg 30 minutes before the intended sleep time. Do not prescribe if the patient has less than 7 hours available for sleep.
6. Reassess at 2 weeks. If 5 mg is tolerated but ineffective, titrate to 10 mg only if the patient is not on a moderate CYP3A4 inhibitor and is able to devote at least 8 hours to sleep.
7. Counsel on complex sleep behaviors, next-morning impairment, and fall precautions (particularly night-time ambulation to the bathroom).
8. Plan a formal reassessment at 3 months. Ongoing insomnia pharmacotherapy should not be continued without periodic re-evaluation of the benefit-risk balance.