NCT06655883 · Merck Sharp & Dohme LLC
A Study of Suvorexant (MK-4305) for the Treatment of Insomnia Disorder in Participants With Opioid Use Disorder (MK-4305-098)
What this study is about
People with opioid use disorder (OUD) can have trouble falling or staying asleep. Researchers want to know if suvorexant will help people with OUD fall asleep and stay asleep. The goal of this study is to learn about the safety of suvorexant and how well people tolerate it. Researchers also want to learn if suvorexant helps people sleep longer compared to people who take placebo.
View original scientific description
People with opioid use disorder (OUD) can have trouble falling or staying asleep. Researchers want to know if suvorexant will help people with OUD fall asleep and stay asleep. The goal of this study is to learn about the safety of suvorexant and how well people tolerate it. Researchers also want to learn if suvorexant helps people sleep longer compared to people who take placebo. A placebo looks like the study medicine but has no actual study medicine in it.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- The main inclusion criteria include but are not limited to the following:
- Has a primary diagnosis of OUD according to Diagnostic and Statistical Manual of Mental Disorder, 5th Edition (DSM-5), and confirmed through the Mini International Neuropsychiatric Interview (MINI).
- Is on a verified, stable dose of medications for opioid use disorder (MOUD) treatment.
- Meets DSM-5 criteria for the diagnosis of Insomnia Disorder
- Has a regular bedtime between 8 PM (20:00) and 1 AM (01:00) and is willing to maintain it for the duration of the study.
- Has not used opioids for a period of at least 4 weeks before entering the study.
Exclusion criteria
- The main exclusion criteria include but are not limited to the following:
- Has current uncontrolled major co-morbid psychiatric illness including major depressive disorder, bipolar disorder, schizophrenia, or any psychiatric condition with psychotic features.
- Has current diagnosis or history within 5 years of any of the following: narcolepsy, sleep paralysis, severe periodic limb movement disorder, restless leg syndrome, cataplexy, circadian rhythm sleep disorder, parasomnia including nightmare disorder, sleep terror disorder, sleepwalking disorder, rapid eye movement (REM) behavior disorder, significant degree of sleep-related breathing disorder, excessive daytime sleepiness (EDS), or primary hypersomnia.
- Is at imminent risk of self-harm.
- Has a known history of stroke that may confound the diagnosis of insomnia.
- Has a clinically significant movement disorder such as akinesia.
- Has a history of hepatitis or live disease.
- Has habitual use of central nervous system (CNS)-depressants or stimulants that may be responsible for the participant's disturbed sleep.
- Has a history of malignancy, ≤3 years prior to start of study, with the exception of nonmelanoma skin cancer, prostate cancer or localized carcinoma in situ of the cervix.
- Has a history of hypersensitivity to more than 3 chemical classes of drugs, including prescription and over-the-counter medications.
- Has donated blood products or had phlebotomy within 8 weeks prior to start of study.
- Has a history of transmeridian travel within 2 weeks prior to start of study.
Where
- New Haven, Connecticut
- Savannah, Georgia
- Baltimore, Maryland
- Marlton, New Jersey
- Oklahoma City, Oklahoma
- Philadelphia, Pennsylvania
- Providence, Rhode Island
- Charleston, South Carolina
- DeSoto, Texas
- Houston, Texas
- Richmond, Virginia
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced May 15, 2026 · Source of record for eligibility and locations