NCT07559500 · National Institute on Alcohol Abuse and Alcoholism (NIAAA)
Tirzepatide s Dopaminergic Effects in Alcohol Use Disorders (AUD)
What this study is about
Background: Glucagon-like peptide 1 (GLP-1) agonist drugs are used to treat diabetes and aid weight loss. They may also help reduce cravings for drugs and alcohol. Researchers want to know if a GLP-1 drug (tirzepatide) can lessen the urge to drink in people with alcohol use disorder (AUD). Objective: To learn how the brains of people with AUD respond to a GLP-1 drug.
View original scientific description
Background: Glucagon-like peptide 1 (GLP-1) agonist drugs are used to treat diabetes and aid weight loss. They may also help reduce cravings for drugs and alcohol. Researchers want to know if a GLP-1 drug (tirzepatide) can lessen the urge to drink in people with alcohol use disorder (AUD). Objective: To learn how the brains of people with AUD respond to a GLP-1 drug. Eligibility: People aged 21 to 65 years with AUD who are non-treatment seeking. They must be enrolled in protocol 14-AA-0181. Healthy volunteers are also needed. Design: This study consists of Part 1 and Part 2. Part 1 (Imaging Procedures): Five healthy volunteers will undergo 2 to 3 combined positron emission tomography/magnetic resonance imaging (PET/MRI) scans, with an interval of 2 to 3 weeks between scans. For each scan, a radioactive substance (tracer) will be administered intravenously. Participants will undergo PET/MRI scanning to assess brain activity during resting state. Methylphenidate (Ritalin) will be administered during each scan. Each imaging session will last approximately 2 hours. Tirzepatide and placebo will not be administered in Part 1. Participants with alcohol use disorder (AUD) are not included in Part 1. The purpose of this part of the study is to assess test/retest reproducibility of the PET/MRI combined scan measures. Part 2 (Randomization to Tirzepatide \& Placebo): Participants will be randomized to receive either Tirzepatide or Placebo first. Healthy Volunteers and AUD participants will receive both treatments in a crossover design. Tirzepatide and placebo will be administered via subcutaneous injection (under the skin) once weekly for 2 to 3 weeks. This treatment period will be followed by 2 to 3 PET/MRI combined imaging scans described in the next paragraph. After a washout interval of approximately 2 to 3 weeks, participants will cross over to the alternate treatment (tirzepatide or placebo), administered once weekly for 2 to 3 weeks. This second treatment period will be followed by an additional 2 to 3 PET/MRI scans. Participants may receive up to 3 doses of tirzepatide and 3 doses of placebo. Part 2 (Imaging Procedures): Healthy Volunteers and participants with an AUD will undergo PET/MRI scans at two time points: following tirzepatide administration and following placebo administration. For each scan a radioactive substance (tracer) will be administered intravenously. Brain activity will be measured during PET/MRI acquisition during resting state. Methylphenidate will be administered during 1 of the scans at each time point. Each imaging session will last approximately 2 hours. Participants will wear a device to track their activity for at least 1 week before each set of scans. They will have tests of their thinking, memory, and attention.
Interventions
DRUG
Tirzepatide
Drug approved for diabetes administered SQ. Subject is blind to drug.
DRUG
Placebo
Placebo will be normal saline administered SQ. Subject is blind to drug.
DRUG
[11C]raclopride plus drug
Radiotracer injection of \[11C\]raclopride during combined PET/MR scan to measure striatal dopamine release (Methylphenidate 0.25 mg/kg injected 45 minutes post radiotracer injection). Subject is not blind to this drug during scan.
DRUG
[11C]NNC-112
\[11C\]NNC-112 PET/MR or PET/CT scan obtained without any drug intervention to measure dopamine D1 receptors.
Primary outcome measures
Part 1 (n=5 healthy volunteers): We will assess the reproducibility of striatal dopamine (DA) measures in response to iv methylphenidate (MP) using PET/MR combined scanning and the bolus infusion protocol in healthy controls.
Time frame: We aim to have each subject (n=5) complete all study procedures within 60 days.
We will measure dopamine in the brain. Dopamine is a chemical messenger that carries signals between brain cells. It plays a role in human behavior. It is also believed to play a role in addiction. In this study, we will use a combined scanner for PET and MRI to measure dopamine with the stimulant drug methylphenidate. Each scan will be done by getting a small amount of a radiotracer through an IV catheter. During each of the two PET/MRI scan sessions each subject will receive IV methylphenidate. We will look at the effects of methylphenidate on brain dopamine. We will also look at brain responses, mood and thinking. The results of each subject's scans will be compared to each other. We will also compare the results to other participants to see if we get similar information.
Part 2 (n=88, 44 healthy volunteers and 44 AUD) : Effects of Tirzepatide on striatal dopamine D1R and D2R availability; striatal DA increase; brain reactivity to MP and to food and alcohol cues in AUD and in healthy controls.
Time frame: We aim to have each subject complete study procedures within 90 days, but this could take longer. AUD participants will undergo a Follow Up phone call about 1 month after imaging scans are complete.
We will measure dopamine levels in the brain. Dopamine is a chemical messenger that carries signals between brain cells. It plays a role in human behavior. It is also believed to play a role in addiction. In this study, we will use a combined scanner for PET and MRI to measure dopamine with the stimulant drug methylphenidate. We will look at the effects of methylphenidate on brain dopamine. To do this we will obtain imaging scans after the subject receives Tirzepatide and a Placebo. We will also look at brain responses, mood and thinking. Results from the same scans on two separate days will be compared to each other. We will also compare the results to other participants to see if we get similar information.
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
- Healthy Volunteer Participants To be eligible to participate in this study, an individual must meet the following criteria:
- Enrollment in 14AA0181.
- Stated willingness to comply with all study procedures and availability for the duration of the study.
- Male or female, ages 21-65 years old.
- Ability to understand and willingness to sign a written informed consent document.
- Have or had any prior experience with stimulant drugs including cocaine, methylphenidate, amphetamine or methamphetamine, or prescription stimulants (prescription or recreational use), whether or not they have had a past substance use disorder. AUD Participants To be eligible, individuals with AUD must meet the following criteria:
- Enrollment in 14AA0181.
- Stated willingness to comply with all study procedures and availability for the duration of the study.
- Male or female, ages 21-65 years old.
- Ability to understand and willingness to sign a written informed consent document.
- DSM 5 diagnosis of mild to moderate AUD.
- Have or had any prior experience with stimulant drugs including cocaine, methylphenidate, amphetamine or methamphetamine, or prescription stimulants (prescription or recreational use), whether or not they have had a past substance use disorder.
- Minimum 2-year history of heavy drinking (SAMSHA s criteria for heavy drinking: for men 5 or more drinks/day on at least 5 different days per month; and for women 4 or more drinks/day on at least 5 different days per month.
- Non treatment seeking AUD participants.
Exclusion criteria
- All Participants (Healthy Volunteers and AUD)
- Presence of ferromagnetic objects in the body that are contraindicated for MRI of the head, fear of enclosed spaces, or other standard contraindication to MRI
- Cannot lie comfortably flat on his/her back for up to 2 hours in the PET/MRI scanner.
- BMI \<23 or \>35 (but no more than 500 lbs). The PET/MRI scanner bed is tested to a weight limit of 500 lbs.
- Have had previous radiation exposure (from X-rays, PET scans, or other exposure) that, with the exposure from this study, would exceed NIH annual research limits as determined by medical history and physical exam.
- Pregnant or breast-feeding: Females of childbearing potential, or with tubal ligation, or are post-menopausal and are age 55 or less will undergo a urine pregnancy test and it must be negative to continue participation. Urine pregnancy tests will be repeated on subsequent days of study (i.e., within 24 hours before study procedures). Females must not be currently breastfeeding.
- Women using oral contraceptives (Part 2 of study). Women of childbearing age who are taking oral contraceptives will be required to switch to a non-oral hormonal contraceptive method (ie implants, injections, or IUDs) or add a barrier method (condoms) for the duration of the study and for 4 weeks after the last dose of study drug after explaining to them that Tirzepatide could make contraceptive less effective. We will not provide nonoral contraceptive medications to participants.
- Severe head trauma with loss of consciousness \> 60 minutes
- Current severe mental illness (schizophrenia, bipolar disorder).
- Montgomery-Asberg depression rating scale (MADRS) total score \> 35 or suicidal thoughts item score \> 3, indicating severe depression or moderate suicidality, respectively.
- Thyroid cancer or family history of thyroid cancer or personal or family history of multiple endocrine neoplasia syndrome type-2 (MEN-2).
- History for cerebral aneurysm.
- Past or present history of chest pain and trouble breathing with activity.
- History of Heart Disease, Hypertension or Cardiovascular disorders.
- History of seizures, anxiety, panic attacks, psychosis or glaucoma which are contraindicated with receiving methylphenidate.
- History of gallbladder disease, pancreatitis, gastroparesis, diabetic retinopathy, acute kidney injury (AKI), as these are contraindicated for Tirzepatide.
- History of allergic reaction to methylphenidate, Tirzepatide or allergic reactions to dyes or preservatives.
- Major medical problems that can permanently impact brain function (e.g., seizures, psychosis, stroke, Alzheimer s disease, Parkinson s disease, traumatic brain injury with loss of consciousness \> 30 minutes, clinically significant arrhythmias except bradycardia, and HIV+).
- Clinically significant laboratory findings that could impact brain function or study procedures (e.g., active infections, significant EKG results, hepatic or renal failure) will be exclusionary.
- Current DSM-5 diagnosis of a psychiatric disorder that required daily psychoactive medications (antidepressant, antipsychotics, stimulants, opioids, benzodiazepines or barbiturates) in the past two months and that could impact brain function at the time of the study as determined by history and clinical exam.
- History of moderate or severe SUD (other than nicotine or alcohol for AUD participants).
- Current severe depression or moderate/severe suicidal ideation.
- Daily current use (past 2 months) of the following drugs/medications are exclusionary: stimulant or stimulant-like drugs or medications (cocaine, methamphetamine, amphetamine, methylphenidate, modafinil); opioid drugs or medications; other GLP-1 or anti-diabetic drugs (e.g., insulin, sulfonylureas) medications, antianginal agents; antiarrhythmics; systemic corticosteroids; anticholinergics; anticoagulants; anticonvulsants; antidepressants with dopaminergic effects (bupropion, sertraline, and dopamine agonists like pramipexole and ropinirole); beta-blocker antihypertensives; antineoplastics; antipsychotics; anxiolytics (benzodiazepine or barbiturates); or lithium. Note that alcohol and cannabis use are not exclusionary but participants cannot be intoxicated on the day of study as evidence of alcohol in breathalyzer or cannabis in saliva. Caffeine and nicotine are permitted but participants will be asked to refrain from consuming caffeine or nicotine products (including cigarettes) two hours prior to the study. Antihistamines are also not exclusionary but should not be used on the day of study.
- \*Non-English speakers (must also be able to read and comprehend English
- We are excluding non-English speakers since the study includes questionnaires that are validated for English and only some are available in Spanish. The fMRI paradigms also require that the subject be able to speak, read and comprehend English. Note that subjects will not be excluded from enrollment onto this study if their urine test or breath alcohol level (BAL) is positive for alcohol/drugs on initial screening. The following guidelines will be followed for positive drug/alcohol screens on study procedure days involving imaging scans and neuropsychological testing for all participants:
- If a subject s breath alcohol (\>0.08%) screen test is positive on days involving imaging (PET/MRI) and NP testing, the procedures will be postponed and rescheduled. We will allow for up to 3 rescheduled study days resulting from positive breath alcohol screens. If subject continues to show up intoxicated they will be withdrawn.
- If urine drug screen is positive for THC-COOH a saliva drug screen will be performed and subject may proceed with study day testing procedures if saliva results for THC are negative. If we are unable to perform the saliva drug screen for any reason, the study day procedures will be postponed. If the urine/saliva drug test is positive on the third rescheduled visit, the participant will be withdrawn from the study. Saliva THC is not required for determining eligibility.
- If a participants urine drug screen test is positive for cocaine, heroin or methamphetamine after 3 days of rescheduling they will be excluded.
Where
- Bethesda, Maryland
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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 Jun 17, 2026 · Source of record for eligibility and locations