Belsomra (Suvorexant) for Women 65 and Older: Transitioning from Midlife to Geriatric Care

Why Your 65th Birthday Changes Your Relationship with Suvorexant

Sleep does not just get harder as you get older. The biology behind it shifts in ways that affect how a drug like suvorexant works inside your body. Suvorexant blocks orexin receptors, which are the brain circuits that keep you alert, allowing natural sleep pressure to take over. That mechanism is the same at 35 as it is at 72, but almost everything downstream is different.

What Changes in Your Brain and Body After 65

Your orexin system itself undergoes age-related changes. Studies in older adults show reduced orexin-1 receptor binding in the frontal cortex compared with younger cohorts, which may mean older brains are already somewhat less orexin-stimulated at baseline [1]. Layering a receptor-blocking drug onto that altered baseline is not automatically harmful, but it does mean clinical effects can be exaggerated.

Your liver also processes suvorexant more slowly. Suvorexant is almost entirely metabolized by CYP3A4, and CYP3A4 activity declines by roughly 20 to 40 percent across the decades after age 60 [2]. The drug's half-life in older adults is approximately 15 hours, compared with about 12 hours in younger healthy adults in the phase III trials, based on population pharmacokinetic modeling in the SUNRISE-1 and SUNRISE-2 trial data [3]. A longer half-life means the drug is still measurably active when you wake up, stand up, and walk to the bathroom.

The Postmenopause Factor Specifically for Women

Estrogen influences CYP3A4 expression. After menopause, when circulating estradiol drops to near zero, some CYP3A4-mediated pathways shift, though the net direction is complex and not fully characterized in older women on suvorexant specifically [4]. Women also carry higher body-fat percentages relative to lean mass than men of the same age, and suvorexant is highly lipophilic, so its distribution volume may be larger, prolonging effects. The FDA label does not specify a dose adjustment for sex or for postmenopausal status, but the pharmacokinetic signals are real enough to warrant caution [5].

A practical framework for the 65-plus transition: think of suvorexant in older women as a drug that behaves like a 15-mg dose even when you prescribe 10 mg, because the slower clearance keeps plasma levels elevated longer. Start at 10 mg, wait at least four weeks before any upward titration, and reassess every six months.

Insomnia in Women Over 65: What Is Actually Going On

Insomnia is not simply "getting older." About 47% of women report significant sleep disturbance during the menopausal transition and afterward, making it the second most common menopause symptom after hot flashes [6]. By age 70, structural changes in sleep architecture reduce slow-wave (deep) sleep by up to 40% compared with age 40, and REM latency shortens [7].

Causes That Often Go Unaddressed in Older Women

• Vasomotor symptoms (VMS): Even years after the final period, about 15% of women still experience hot flashes that fragment sleep [6]. If VMS is the primary driver, treating the hot flashes with menopausal hormone therapy (MHT) may resolve insomnia without a sleep-specific drug.
• Genitourinary syndrome of menopause (GSM): Urinary urgency and nocturia from GSM wake women two to four times per night. Suvorexant does not fix nocturia. Addressing GSM with vaginal estrogen first can reduce nighttime awakenings before adding a sleep drug.
• Restless legs syndrome (RLS): Prevalence rises in postmenopausal women. RLS is a contraindication to antihistamine sleep aids and is poorly addressed by suvorexant. Confirm the diagnosis before prescribing.
• Sleep-disordered breathing: Obstructive sleep apnea prevalence in women jumps after menopause and approaches male rates by the late 60s [8]. Suvorexant is not contraindicated in mild-to-moderate sleep apnea, unlike benzodiazepines, but an undiagnosed OSA workup should precede chronic sleep medication in any woman over 65 with snoring, morning headaches, or witnessed apneas.
• Depression and anxiety: Both are independent causes of insomnia and are underdiagnosed in older women. An insomnia drug layered on top of untreated major depression treats a symptom and misses the condition.

Cognitive Baseline Matters

The 2015 AASM clinical practice guideline for chronic insomnia in adults recommends cognitive behavioral therapy for insomnia (CBT-I) as the first-line treatment at any age [9]. For women over 65, CBT-I is especially important before or alongside any pharmacotherapy, because cognitive side effects from sedating drugs are harder to reverse than they are to prevent.

Suvorexant Dosing in Women 65 and Older

The starting dose of suvorexant is 10 mg taken no more than 30 minutes before bedtime, with at least seven hours remaining before planned waking time. The maximum approved dose is 20 mg nightly. These numbers apply to both younger adults and older adults per the FDA prescribing information [5].

Why the Starting Dose Matters More at 65

In the phase III SUNRISE-1 trial, suvorexant 20 mg reduced wake after sleep onset (WASO) by a mean of 28 minutes versus placebo in adults aged 18 to 64, and results were directionally similar in the 65-plus subgroup, though the older subgroup showed more next-day somnolence [3]. The trial enrolled more women than men (approximately 60% female), which is one reason the data are somewhat more applicable to women than many drug trials [3].

Because of the extended half-life in older adults, the 10 mg starting dose in women 65 and older is not a conservative suggestion. It is the clinically appropriate starting point. Moving to 20 mg should only happen if 10 mg produces no meaningful benefit after at least four weeks, and only after confirming the patient is not already experiencing next-day impairment at 10 mg.

Dose Adjustments Based on Drug Interactions

Women in their 60s and 70s are frequently prescribed medications that inhibit CYP3A4. Common examples include:

• Fluconazole (antifungal): Even a short course raises suvorexant exposure substantially. The FDA label states the combination should be avoided [5].
• Diltiazem and verapamil (heart rate control): These are moderate CYP3A4 inhibitors. Co-prescribing with suvorexant approximately doubles suvorexant exposure per pharmacokinetic interaction data [2]. Reduce suvorexant to 5 mg (off-label) or avoid.
• Clarithromycin (antibiotic): Strong CYP3A4 inhibitor. Suvorexant is contraindicated during courses of strong CYP3A4 inhibitors [5].
• Rifampin (used in some TB or bone infections): Strong CYP3A4 inducer. Makes suvorexant nearly ineffective; avoid combination.

Review the full medication list at every care transition. Older women see multiple specialists and may accumulate CYP3A4-affecting drugs without any single provider noticing.

Falls Risk: The Safety Issue That Overrides Everything Else

Falls are the leading cause of injury death in women over 65 in the United States [10]. Any sedating drug in this age group must be evaluated against that backdrop. The 2023 American Geriatrics Society Beers Criteria lists all orexin receptor antagonists, including suvorexant, as medications to use with caution in older adults due to increased fall and fracture risk [11].

What the Evidence Actually Shows

The SUNRISE trials were not powered or designed to detect falls as a primary outcome. Post-marketing and observational data show that next-day psychomotor impairment with suvorexant in adults over 65 is measurable, even at 10 mg, and can persist for up to 9 hours after a midnight awakening [12]. A 2019 study in the Journal of Clinical Sleep Medicine found that older adults taking orexin antagonists had a next-morning driving impairment signal comparable to moderate alcohol intoxication, though this was a small study and extrapolation should be careful [12].

Women specifically are at higher fall risk than men of the same age, partly because postmenopausal bone loss means fractures from falls are more severe. A fall that causes a hip fracture in a 70-year-old woman carries a one-year mortality of approximately 20 to 30% [13].

Practical Fall-Risk Mitigation

• Keep a night light on or use a motion-sensor light between bedroom and bathroom.
• Do not get out of bed immediately after waking. Sit at the edge for 60 seconds first.
• Avoid alcohol entirely while on suvorexant. Alcohol extends CNS depression synergistically.
• Tell your pharmacist about suvorexant whenever a new medication is prescribed.
• Reassess fall risk formally using the CDC STEADI tool at every annual visit [10].

Transitioning Care: What the Handoff from Perimenopausal to Geriatric Care Should Include

The transition from a gynecologist or women's health NP managing perimenopause to a geriatrician or internist managing the full complexity of older adulthood is a genuine clinical risk point for sleep medication continuity. Suvorexant may have been started at 55 during the worst of perimenopausal insomnia and then simply continued on refill. The 65th birthday is a meaningful checkpoint.

What Every Handoff Should Document

1. The original indication: Was it sleep-onset insomnia, sleep-maintenance insomnia, or both? Has the indication changed?
2. Concurrent vasomotor symptom status: Is menopausal hormone therapy still being used? If MHT is being discontinued, sleep may worsen temporarily and suvorexant may still be appropriate. If MHT is newly started, sleep may improve and suvorexant may be weaned.
3. Current dose and duration of use: Long-term use of suvorexant beyond 12 months has limited controlled trial data. The longest controlled trial data available run to 12 months [3].
4. Fall history in the past 12 months: Even one fall changes the risk-benefit calculation.
5. Cognitive status: Any new memory concerns, MCI screening, or dementia workup should be documented before continuing a sedating drug.
6. Current CYP3A4-affecting medications: Full reconciliation at every transition.

The Role of CBT-I at the Transition Point

CBT-I is not just for starting treatment. A 65th birthday is an excellent time to refer for CBT-I even if suvorexant is being continued, because CBT-I can reduce sleep medication dependence. A Cochrane review of CBT-I in older adults found it produced clinically meaningful improvements in sleep efficiency with effect sizes comparable to pharmacotherapy, and without the safety concerns [14]. Telehealth CBT-I programs are now widely available, removing the need for in-person visits.

Who Suvorexant Is and Is Not Right for After 65

Suvorexant may be appropriate for women over 65 who:

• Have diagnosed chronic insomnia disorder (not just occasional poor sleep) confirmed with sleep diary or actigraphy.
• Have tried and completed a full course of CBT-I with insufficient response.
• Do not have a strong concurrent CYP3A4 inhibitor in their medication list.
• Have no significant fall history or well-controlled fall risk factors.
• Have had sleep apnea ruled out or are already treated with CPAP.

Suvorexant is a poor fit for women over 65 who:

• Have had one or more falls in the past year.
• Have a dementia diagnosis or significant MCI, as next-day cognitive impairment adds to baseline deficits.
• Are taking diltiazem, verapamil, or any strong CYP3A4 inhibitor regularly.
• Use alcohol regularly in the evening.
• Have untreated depression driving the insomnia, where treating the depression would address the root cause.

Alternative approaches worth discussing with your provider include low-dose doxepin 3 to 6 mg (the only other FDA-approved option specifically for sleep-maintenance insomnia), ramelteon for sleep-onset difficulty (lower fall risk profile, though less effective for maintenance), and CBT-I delivered via app or telehealth [15].

Pregnancy and Lactation Safety

This section is included per WomanRx editorial policy for all drug articles. For most women reading this at age 65 or older, pregnancy is not a consideration. However, women in their early 60s who have not confirmed menopause with FSH testing and at least 12 months of amenorrhea remain at low but non-zero risk of pregnancy, and this information applies to them.

Pregnancy

Suvorexant is FDA Pregnancy Category not formally assigned under the current labeling system (it was approved after the 2015 labeling rule change). The label states that animal reproductive studies showed embryo-fetal toxicity at exposures exceeding human therapeutic doses, and there are no adequate human pregnancy data [5]. Suvorexant should be avoided in pregnancy. Women in their early 60s who are not certain they are postmenopausal should use reliable contraception if taking suvorexant.

Lactation

There are no human data on suvorexant transfer into breast milk. Animal data suggest transfer occurs. The drug's long half-life of approximately 15 hours and high lipophilicity are pharmacologically consistent with meaningful milk transfer [5]. Breastfeeding is not expected to be ongoing at the ages this article primarily addresses, but the data gap is documented here for completeness. Any woman who is lactating at any age should not take suvorexant without explicit discussion with her provider.

Contraception

Women who are perimenopausal and being prescribed suvorexant should use reliable contraception until menopause is confirmed. Strong CYP3A4 inducers (rifampin, carbamazepine) can reduce suvorexant efficacy, but suvorexant does not meaningfully affect hormonal contraceptive pharmacokinetics based on available interaction data [5].

Monitoring: What Should Happen at Every Annual Review

Once suvorexant is established, it should not simply be refilled indefinitely without structured review. The following checks should happen at least annually, and more often in the first year or after any care transition:

• Sleep diary or validated scale: The Pittsburgh Sleep Quality Index (PSQI) or Insomnia Severity Index provides a documented baseline for comparison [16].
• Fall screening: CDC STEADI tool or equivalent.
• Medication reconciliation: Full list reviewed for new CYP3A4 interactions.
• Cognitive screening: MoCA or MMSE at least annually, with particular attention to any new decline.
• Dose necessity check: Can the dose be reduced or the drug discontinued? A planned taper trial every 12 to 24 months is reasonable for anyone who has achieved good sleep hygiene.
• MHT status review: If MHT is started, continued, or stopped, expect sleep to change and adjust suvorexant accordingly.

The American Geriatrics Society recommends a deprescribing review for all sedating sleep medications at each visit in adults over 65 [11]. That recommendation applies to suvorexant.

Evidence Gaps Specific to Older Women

Women have been historically underrepresented in sleep pharmacology trials, and older women even more so. The SUNRISE trials enrolled approximately 60% women overall but did not publish sex-stratified results by age subgroup, meaning we do not have powered data on suvorexant efficacy and adverse events specifically in women over 65 [3]. What we know is mostly extrapolated from:

• The full age 65+ subgroup (both sexes combined).
• Pharmacokinetic modeling that includes age and sometimes sex as covariates.
• Post-marketing surveillance that is not systematically stratified by sex.

This is a genuine gap. A 72-year-old woman on suvorexant is relying on data from trials that did not specifically study her. Her provider should acknowledge that, use the lowest effective dose, and monitor more closely than the trial data alone might suggest.