REPOSE Study: Reducing Delirium by Enhancing Postoperative Sleep With Suvorexant

Inclusion Criteria:

1. Age 65 and older

2. Undergoing non-cardiac, non-intracranial surgery, any surgical procedure notinvolving the skull, brain, cerebrovascular structures

3. Scheduled postoperative inpatient overnight stay

4. Able to give informed consent or has legally authorized representative able to giveinformed consent on their behalf

5. English-speaking

Exclusion Criteria:

1. Inmate of correctional facility

2. Body mass index> 40

3. Legal blindness

4. Unable to perform study related questionnaires and assessments

5. Use of outpatient sedating sleep aids > 2 times per any week in 1 month precedingday of surgery. Sedating sleep aids, *See list Below.

6. History of psychotic disorder, including schizophrenia, schizoaffective disorder,schizophreniform or brief psychotic disorder.

7. History of liver failure with documented international normalized ratio (INR) of >1.2 or with history of hepatic encephalopathy

8. History of severe sleep apnea or obesity hypoventilation syndrome requiring homebilevel positive airway pressure therapy or home ventilator or other forms ofnoninvasive ventilation

9. Chronic lung disease requiring home oxygen therapy

10. History of narcolepsy

11. Use of systemic (oral, intravenous, intramuscular, subcutaneous) moderate or strongCYP3A inhibitors within 1 week prior to surgery, *See list below

12. Use of systemic (oral, intravenous, intramuscular, subcutaneous) moderate or strongCYP3A inducers within 1 week prior to surgery, *See list below.

13. Current or planned administration of digoxin, or is currently experiencing digoxintoxicity

14. Undergoing surgery that will result in inability to take medications by mouthincluding laryngectomy, tracheostomy, and oral resection/reconstructive surgery

15. Undergoing surgery that will require postoperative strict bowel rest, includinggastrectomy, esophagectomy, and pancreaticoduodenectomy

16. Undergoing surgery in an area that will make it unsafe to wear a headband, such asscalp or forehead procedures.

17. Inappropriate for study inclusion based on the judgement of the principalinvestigator

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