Delirium in Old AgePhase 2REPOSENCT05733286
REPOSE Study: Reducing Delirium by Enhancing Postoperative Sleep With Suvorexant
A Phase 2 study testing Suvorexant 20 mg in people with Delirium in Old Age, run by Duke University at 1 site in United States.
Trial summary
This research study will evaluate the effectiveness of postoperative administration of a drug called suvorexant, to improve postoperative sleep and decrease the severity of delirium (serious confusion) in adults 65 years and older undergoing non-cardiac surgery. Read more about this study
- Who is it for?
- Ages 65 years and olderHealthy volunteers can take part
- Conditions the study is for
- Delirium in Old Age
- What is being tested?
- Suvorexant 20 mg
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 142 participants
- Where
- 1 siteUnited States
- Study dates
- 28 Jun 2023to 7 Jul 2025
- Phase
- Phase 2
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 65 years and older
- All sexes
- Healthy volunteers accepted
- Older adult
Who may be able to join
- Age 65 and older
- Undergoing non-cardiac, non-intracranial surgery, any surgical procedure not involving the skull, brain, cerebrovascular structures
- Scheduled postoperative inpatient overnight stay
- Able to give informed consent or has legally authorized representative able to give informed consent on their behalf
- English-speaking
Who cannot join
- Inmate of correctional facility
- Body mass index> 40
- Legal blindness
- Unable to perform study related questionnaires and assessments
- Use of outpatient sedating sleep aids > 2 times per any week in 1 month preceding day of surgery. Sedating sleep aids, *See list Below.
- History of psychotic disorder, including schizophrenia, schizoaffective disorder, schizophreniform or brief psychotic disorder.
Show all 22Show fewer
- History of liver failure with documented international normalized ratio (INR) of >1.2 or with history of hepatic encephalopathy
- History of severe sleep apnea or obesity hypoventilation syndrome requiring home bilevel positive airway pressure therapy or home ventilator or other forms of noninvasive ventilation
- Chronic lung disease requiring home oxygen therapy
- History of narcolepsy
- Use of systemic (oral, intravenous, intramuscular, subcutaneous) moderate or strong CYP3A inhibitors within 1 week prior to surgery, *See list below
- Use of systemic (oral, intravenous, intramuscular, subcutaneous) moderate or strong CYP3A inducers within 1 week prior to surgery, *See list below.
- Current or planned administration of digoxin, or is currently experiencing digoxin toxicity
- Undergoing surgery that will result in inability to take medications by mouth including laryngectomy, tracheostomy, and oral resection/reconstructive surgery
- Undergoing surgery that will require postoperative strict bowel rest, including gastrectomy, esophagectomy, and pancreaticoduodenectomy
- Undergoing surgery in an area that will make it unsafe to wear a headband, such as scalp or forehead procedures.
- Inappropriate for study inclusion based on the judgement of the principal investigator
- Exclusionary Medications:
- Moderate CYP3A inhibitors: Amprenavir, Aprepitant, Atazanavir, Ciprofloxacin, Diltiazem, Erythromycin, Fluconazole, Fosamprenavir, Imatinib, Verapamil, grapefruit juice.
- Strong CYP3A inhibitors: Ketoconazole, Itraconazole, Posaconazole, Clarithromycin, Nefazodone, Ritonavir, Saquinavir, Nelfinavir, Indinavir, Boceprevir, Telaprevir, Telithromycin, Conivaptan
- Moderate/Strong CYP3A inducers: Apalutamide, Carbamazepine, Enzalutamide, Ivosidenib, lumacaftor, Mitotane, Phenytoin, Rifampin, St. John's wort, Bosentan, Cenobamate, Dabrafenib, Efavirenz, Etravirine, Lorlatinib, Pexidartinib, Phenobarbital, Primidone, Sotorasib.
- Sedating sleep aids: Mirtazapine, Trazodone, Flurazepam, Temazepam, Triazolam, Estazolam, Quazepam, Clonazepam, Lorazepam, Midazolam, Alprazolam, Diazepam, Zolpidem, Zaleplon, Eszopiclone, Diphenhydramine, Doxylamine, Hydroxyzine, Suvorexant, Doxepin
Trial locations and contacts
1 site in 1 country.
United States1 site
Duke University Medical Center
Durham, North Carolina, 27710
About this study
Official title: Efficacy of Suvorexant to Improve Postoperative Sleep and Reduce Delirium Severity in Older Surgical Patients: A Double-blinded, Randomized, Placebo-controlled Trial
This research study will evaluate the effectiveness of postoperative administration of a drug called suvorexant, to improve postoperative sleep and decrease the severity of delirium (serious confusion) in adults 65 years and older undergoing non-cardiac surgery.
Read the detailed description
Suvorexant is an FDA-approved drug to treat a condition called insomnia, a sleep disorder characterized by difficulty falling asleep, staying asleep or getting good quality sleep, and has been found to have a good safety profile in older adults. Since older surgical patients often have difficulties with sleep, suvorexant might improve sleep after surgery but this remains unknown. Because difficulties with sleeping after surgery have been associated with a disorder of severe confusion called delirium, administration of suvorexant after surgery may also help prevent delirium or decrease its severity.
Participants will receive either a placebo or suvorexant by mouth (or feeding tube if present) on the first three nights after surgery while in the hospital. Prior to surgery, participants will be asked to wear a wristband sleep monitor and complete several questionnaires about their sleep, brief thinking and memory tests, a test of attention, and a measurement of their pupil size with a special camera. After surgery, participants will wear a comfortable headband device that records the electrical signals from the brain to measure the amount and depth of their sleep. This device will be worn for the first 3 nights from 9:00 PM to 6:00 AM after surgery or until hospital discharge, whichever occurs first. After surgery, participants will also answer several questions about their sleep quality and redo some of the brief thinking and memory tests (delirium tests), attention tests, and pupil size measurements. Additionally, the investigators will collect a blood sample prior to surgery and on the first two days after surgery.
Benefits of this study include the possibility of improved sleep after surgery and fewer problems with confusion and thinking and memory problems after surgery.
Risks of participation include headache, diarrhea, dry mouth, cough, abnormal dreams, dizziness, daytime tiredness and discomfort from the blood draw.
- Conditions
- Delirium in Old Age
- Being tested
- Suvorexant 20 mg, Placebo
- Keywords
- Sleep
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Suvorexant 20 mgDrug
Administer Suvorexant versus placebo every evening for Post-Operative Day (POD) 0,1, \&2
PlaceboDrug
Administer Suvorexant versus placebo every evening for Post-Operative Day (POD) 0,1, \&2
| Study group | Role | What they receive |
|---|---|---|
| Suvorexant Arm | Active comparator | Not described Receives: Drug: Suvorexant 20 mg |
| Placebo Arm | Placebo comparator | Not described Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Total Sleep Time (TST) on the First Postoperative Night
Total sleep time (TST) on first postoperative night that patient received study drug, as measured by electroencephalography (EEG). Total sleep time includes amount of time in sleep during the lights out period (defined between 21:00 and 06:00).
Measured: The first postoperative night that the participants received study drug (D0)
Secondary outcomes (1)
Peak Postoperative Delirium Severity Score
Three minute Confusion Assessment Method (3D-CAM ) severity scores up through postoperative day 5 or discharge, whichever occurs first, in patients receiving suvorexant vs placebo. Scores range from 0-20 and the higher score is worse.
Measured: Postoperative Day 0 through Day 5
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Feb 2023
- Study start28 Jun 2023
- Primary completion25 Jun 2025
- Study completion7 Jul 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Delirium in Old AgeStudies of the same condition, open and under way.
- More trials run by Duke UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Investigator
- Enrolment
- 142 participants (actual)
Sponsor and investigators
- Lead sponsor
- Duke University
- Sponsor type
- University, hospital or other
- Collaborators
- Merck Sharp & Dohme LLC
- Responsible party
- Sponsor
- Investigators
- Michael Devinney Jr, MD, PhD, Principal investigator, Duke University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05733286
- Sponsor's protocol ID
- Pro00111869
- Acronym
- REPOSE
- Status last verified
- Dec 2025
- First submitted
- 30 Jan 2023
- Last updated
- 15 Jan 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Fallon JM, Hashemaghaie M, Peterson CE, Tran D, Wu SR, Valdes JM, Pedicini NM, Adams ME, Soltis M, Mansour W, Wright MC, Raghunathan K, Treggiari MM, Sasannejad C, Devinney MJ. Protocol and design of the REPOSE study: a double-blinded, randomised, placebo-controlled trial to evaluate the efficacy of suvorexant to improve postoperative sleep and reduce delirium severity in older patients undergoing non-cardiac surgery. BMJ Open. 2025 Mar 13;15(3):e091099. doi: 10.1136/bmjopen-2024-091099.
PubMed 40081971
Study at a glance
From the registry record, last updated by the sponsor on 15 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Efficacy of Suvorexant to Improve Postoperative Sleep and Reduce Delirium Severity in Older Surgical Patients: A Double-blinded, Randomized, Placebo-controlled Trial
- ClinicalTrials.gov ID
- NCT05733286
- Acronym / sponsor ID
- REPOSE / Pro00111869
- Conditions
- Delirium in Old Age
- Keywords
- Sleep
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 142 participants (actual)
- Lead sponsor
- Duke UniversityUniversity, hospital or other
- Collaborators
- Merck Sharp & Dohme LLC
- Study start
- 28 Jun 2023 (actual)
- Primary completion
- 25 Jun 2025 (actual)
- Study completion
- 7 Jul 2025 (actual)
- First posted
- 17 Feb 2023 (actual)
- Results
- Posted 15 Jan 2026
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This research study will evaluate the effectiveness of postoperative administration of a drug called suvorexant, to improve postoperative sleep and decrease the severity of delirium (serious confusion) in adults 65 years and older undergoing non-cardiac surgery.
Detailed description
Suvorexant is an FDA-approved drug to treat a condition called insomnia, a sleep disorder characterized by difficulty falling asleep, staying asleep or getting good quality sleep, and has been found to have a good safety profile in older adults. Since older surgical patients often have difficulties with sleep, suvorexant might improve sleep after surgery but this remains unknown. Because difficulties with sleeping after surgery have been associated with a disorder of severe confusion called delirium, administration of suvorexant after surgery may also help prevent delirium or decrease its severity.
Participants will receive either a placebo or suvorexant by mouth (or feeding tube if present) on the first three nights after surgery while in the hospital. Prior to surgery, participants will be asked to wear a wristband sleep monitor and complete several questionnaires about their sleep, brief thinking and memory tests, a test of attention, and a measurement of their pupil size with a special camera. After surgery, participants will wear a comfortable headband device that records the electrical signals from the brain to measure the amount and depth of their sleep. This device will be worn for the first 3 nights from 9:00 PM to 6:00 AM after surgery or until hospital discharge, whichever occurs first. After surgery, participants will also answer several questions about their sleep quality and redo some of the brief thinking and memory tests (delirium tests), attention tests, and pupil size measurements. Additionally, the investigators will collect a blood sample prior to surgery and on the first two days after surgery.
Benefits of this study include the possibility of improved sleep after surgery and fewer problems with confusion and thinking and memory problems after surgery.
Risks of participation include headache, diarrhea, dry mouth, cough, abnormal dreams, dizziness, daytime tiredness and discomfort from the blood draw.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, care provider, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Suvorexant Arm | Active comparator | Drug: Suvorexant 20 mg |
| Placebo Arm | Placebo comparator | Drug: Placebo |
Who may qualify
- Ages
- 65 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Older adult
Key inclusion criteria (5 listed)
- Age 65 and older
- Undergoing non-cardiac, non-intracranial surgery, any surgical procedure not involving the skull, brain, cerebrovascular structures
- Scheduled postoperative inpatient overnight stay
- Able to give informed consent or has legally authorized representative able to give informed consent on their behalf
- English-speaking
Key exclusion criteria (22 listed)
- Inmate of correctional facility
- Body mass index> 40
- Legal blindness
- Unable to perform study related questionnaires and assessments
- Use of outpatient sedating sleep aids > 2 times per any week in 1 month preceding day of surgery. Sedating sleep aids, *See list Below.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Suvorexant 20 mgAdminister Suvorexant versus placebo every evening for Post-Operative Day (POD) 0,1, \&2 | Drug | Suvorexant Arm |
| PlaceboAdminister Suvorexant versus placebo every evening for Post-Operative Day (POD) 0,1, \&2 | Drug | Placebo Arm |
Primary outcome
Total Sleep Time (TST) on the First Postoperative Night
Time frame: The first postoperative night that the participants received study drug (D0)
Total sleep time (TST) on first postoperative night that patient received study drug, as measured by electroencephalography (EEG). Total sleep time includes amount of time in sleep during the lights out period (defined between 21:00 and 06:00).
1 secondary outcome
Peak Postoperative Delirium Severity Score
Time frame: Postoperative Day 0 through Day 5
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 Jan 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Derived from this study: PubMed 40081971Fallon JM, Hashemaghaie M, Peterson CE, Tran D, Wu SR, Valdes JM, Pedicini NM, Adams ME, Soltis M, Mansour W, Wright MC, Raghunathan K, Treggiari MM, Sasannejad C, Devinney MJ. Protocol and design of the REPOSE study: a double-blinded, randomised, placebo-controlled trial to evaluate the efficacy of suvorexant to improve postoperative sleep and reduce delirium severity in older patients undergoing non-cardiac surgery. BMJ Open. 2025 Mar 13;15(3):e091099. doi: 10.1136/bmjopen-2024-091099.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Michael Devinney Jr, MD, PhD principal investigator
Duke University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Suvorexant 20 mg in people with Delirium in Old Age, run by Duke University at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 22 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 15 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Yes. Results are posted in the registry (first posted 15 Jan 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Total Sleep Time (TST) on the First Postoperative Night (time frame: The first postoperative night that the participants received study drug (D0)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05733286, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 15 Jan 2026.