A Phase 1/2 interventional study of Placebo and Suvorexant in Healthy Volunteers and Alcohol Use Disorder (AUD), sponsored by National Institute on Alcohol Abuse and Alcoholism (NIAAA). Recruiting at 1 site in United States. Open to participants aged 18 Years to 75 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-09-29.
Sponsored by National Institute on Alcohol Abuse and Alcoholism (NIAAA) · Phase 1/2, Interventional, and Basic science
Background:
Alcohol use disorder (AUD) is a leading cause of disease and death worldwide. New treatments for AUD are needed. Dopamine, a chemical that carries signals between brain cells, is thought to play a role in alcohol addiction. Researchers want to learn how Suvorexant, a drug used to treat sleep disorders, affects dopamine receptors in the brain.
Objective:
To see how Suvorexant affects dopamine receptors in people with AUD and in healthy people.
Eligibility:
People aged 18 to 75 years seeking treatment for AUD. Healthy volunteers are also needed.
Design:
Participants with AUD will stay in the clinic for at least 10-28 days for alcohol detoxification. They will receive normal treatment for AUD.
Suvorexant is a medicine used to treat sleep problem that is taken taken by mouth, once a day. Some participants will take the study drug. Others will take a placebo. The placebo looks like the study drug but does not contain any medicine. Participants will not know which they are taking.
Participants will wear a device that looks like a wristwatch to track their movements during their clinic stay.
Participants will have blood tests and 3 brain imaging scans before starting on the study drug: 2 positron emission tomography (PET) and 1 magnetic resonance imaging (MRI) scan. They will be injected with a radioactive tracer during each PET scan.
Participants will have tests to assess their thinking, memory, and attention. They will have sleep studies.
Imaging scans and other tests will be repeated at the end of the study.
Healthy volunteers will have 1 MRI and 2 PET scans. They will have tests to assess of their thinking, memory, and attention. They will wear a wristwatch like movement monitor for 1 week.
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Study Description:
This protocol examines effects of a 10-28 day course of suvorexant treatment on brain dopamine receptors, brain reactivity to cues and symptomatology in individuals with alcohol use disorder (AUD) undergoing detoxification. We hypothesize that suvorexant compared to placebo will (1) increase striatal dopamine D2 receptors while decreasing the balance of D1 to D2 receptor signaling (D1R/D2R) and (2) improve sleep and reduce alcohol craving and dysphoria.
Objectives:
Primary objectives: To examine the impact of suvorexant on dopamine receptors in adults with AUD undergoing detoxification and to compare against baseline measures in healthy controls.
Secondary objectives: To examine suvorexant's effects on sleep quality and alcohol craving in adults with AUD undergoing detoxification.
Endpoints:
Primary Endpoint: Suvorexant's effects on brain dopamine receptors:
-Striatal dopamine D1 and D2 receptor availabilities and D1R/D2R ratios
Secondary Endpoints: Effects of suvorexant on:
Exploratory Endpoints:
To be eligible to participate in this study, an individual must meet all of the following criteria:
Ability to understand and the willingness to sign a written informed consent document.
To be eligible to participate in this study, an individual with AUD must meet all of the "All Participants" inclusion criteria (listed above) and also meet the following criteria:
EXCLUSION CRITERIA:
-All Participants
An individual who meets any of the following criteria will be excluded from participation:
Females must not be currently breastfeeding.
Hepatic enzymes (ALT/GPT, AST/GOT, Total Bilirubin, Direct Bilirubin) that are >5x the upper limit of normal, indicating severe hepatic impairment.
Non-English speakers (must also be able to read and comprehend English).
The intent of the research has no prospect of direct benefit to the subject. Therefore, we are excluding non-English speakers in this research study since it includes the administration of questionnaires, surveys and assessments that are validated for English; only some are available in Spanish. In addition, our fMRI paradigms require that the subject be able to speak, read and comprehend English.
-AUD Participants
An individual with AUD who meets any of the "All Participants" exclusion criteria (listed above) or any of the following criteria will be excluded from participation in this study:
Note that AUD subjects will not be excluded from enrollment onto this study if their urine test or breath alcohol level (BAL) is positive for drugs/alcohol on initial screening. The following guidelines will be followed for positive drug/alcohol screens on study procedure days involving imaging scans:
-If a subject's urine drug/breath alcohol (>=0.08%) screen test is positive on days involving imaging (MRI and/or PET), the procedures will be postponed until BrAC \<0.08. This is not expected to happen in most cases especially since participants will have been detoxifying for 1-5 days (possibly longer) and should no longer test positive for BrAC at this point. After initial screening under 14AA0181, subjects will be in the inpatient unit detoxifying.
We minimized exclusion criteria pertaining to current medication use in the AUD group participants to make recruitment feasible and so the outcome can be better generalized to vulnerable AUD populations which have high rates of comorbid mental and physical illness requiring medication. Note however that although current daily use of naltrexone is an exclusion per above, once the imaging scans and study drug dosing are completed, standard of care treatment will be started a few days prior to discharge and this could include taking naltrexone daily. This will not be considered a violation or non-compliance or deviation from criteria listed above once the imaging studies are complete. Standard of care may start within 24 hours of last study drug medication dose or last brain imaging scan under the current protocol, whichever happens last. This treatment is initiated for a few days under the 14AA0181 Natural History protocol prior to discharge from the unit.
-Control Participants
A control individual who meets any of the criteria listed under "All Participants" exclusion criteria (listed above) or any of the following criteria will be excluded from participation in this study:
When developing this protocol to include healthy volunteers, we needed a population not taking medications that could impact our interpretation of dopamine level measurements, since we are hoping to get estimates of 'baseline' dopamine levels in this control population.
Note that subjects will not be excluded from enrollment onto this study if their urine test or breath alcohol level (BAL) is positive for drugs/alcohol on initial screening. The following guidelines will be followed for positive drug/alcohol screens on study procedure days involving imaging scans in HV participants:
Healthy Volunteers will receive two PET scans and one MRI session without any treatment.
AUD subjects randomized to receive placebo for up to 28 days during inpatient treatment.
Drug: Placebo
AUD subjects randomized to receive Suvorexant (20 mg po) for up to 28 days during inpatient treatment.
Drug: Suvorexant
The placebo will be a tablet, but only containing inert inactive ingredients.
Drug approved for improving sleep
To examine the impact of suvorexant on dopamine receptors in adults with AUD undergoing detoxification and to compare against baseline measures in healthy controls.
We hypothesize that suvorexant compared to placebo will (1) increase striatal dopamine D2 receptors while decreasing the balance of D1 to D2 receptor signaling (D1R/D2R) and (2) improve sleep and reduce alcohol craving and dysphoria.
Time frame: 3 years
To examine suvorexant's effects on sleep quality and alcohol craving in adults with AUD undergoing detoxification.
We hypothesize that suvorexant compared to placebo will improve sleep and reduce alcohol craving and dysphoria.
Time frame: 3 years
Plan to share: No — Data is analyzed by subject group and not on an individual basis.
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National Institute on Alcohol Abuse and Alcoholism (NIAAA)