Impact of GLP-1 Receptor Agonist Therapy on Alcohol Pharmacokinetics (TAP)

August 5, 2026 updated by: University of Wisconsin, Madison
This study is to learn how the weight loss drug tirzepatide (Zepbound) changes the way a body handles alcohol. 5 participants aged 21-55 who take Zepbound will be enrolled and can expect to be on study for up to 4 weeks.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Participants will:

  • Arrive to study visit in a fasted state
  • Provide blood, breath, and urine samples prior to intervention
  • Complete baseline cognitive assessments
  • Self-administer the intervention (time 0), followed by breakfast (time 30 minutes)
  • Complete subjective and cognitive assessments throughout treatment visit
  • Provide blood, breath, and urine samples throughout treatment visit
  • Consume lunch 260 minutes after dosing
  • Complete study visit at 360 minutes
  • Complete a final study survey

Primary Objective: Characterize the pharmacokinetics of ethanol in participants receiving maintenance Glucagon-like peptide-1 (GLP-1) receptor agonist (RA) therapy (tirzepatide).

Secondary Objectives:

- Determine the effects of GLP-1 RA therapy on alcohol-induced impairment, as measured by

  • objective performance
  • subjective impairment assessments
  • risk perception

Correlative Objectives

  • Define the exposure-response relationship between biological alcohol concentrations (breath and blood) and functional impairment to determine if Primary Objective
  • Characterize the pharmacokinetics of ethanol in participants receiving maintenance GLP-1 RA therapy (tirzepatide).

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
5

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • United States
    • Wisconsin
      • Madison, Wisconsin, United States, 53792
        • University Of Wisconsin

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • At least 21 years of age, no older than 55 years of age
  • BMI 30-45 kg/m2
  • Taking stable dose of prescribed, branded tirzepatide for at least 28 days
  • Self-reported regular alcohol consumption
  • Good mental health as determined by self-reported responses to the Psychopathology Screener and review by Study Physician as necessary
  • Absence of any major medical, cardiovascular, endocrine, and neurological condition as determined by self-reported responses to the Medical History Screener
  • In possession of a valid drivers' license with at least two years of driving experience
  • English-speaking (able to provide consent and complete questionnaires)
  • Written Informed Consent

Exclusion Criteria:

  • AUDIT score of >8 requires Study Physician review
  • Use of compounded GLP-1 RA
  • History of or current substance use disorder as determined by self-reported responses to the Internalizing, Externalizing, and Substance Use Disorder Screener, Drug Use Disorders Identification Test, Alcohol Use Disorder Identification Test
  • Pregnancy or lactation (pregnancy test, if needed)
  • Use of medications that may impact cognitive ability or potentiate alcohol (e.g., mood stabilizers, sedatives)
  • Use of medications that are known to significantly delay gastric emptying as determined by Study Physician
  • History of pancreatitis, severe gastroparesis, or personal or family history of medullary thyroid or multiple endocrine neoplasia syndrome type 2

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Healthy adults on Tirzepatide
Participants will complete a screening and enrollment visit, one study visit, and a follow-up correspondence over the course of approximately 4 weeks.
Drug: Acute Ethanol Dose
Time 0, participants will self-administer an oral ethanol beverage (vodka and sugar-free cherry Kool aid) calculated to reach a peak Breath Alcohol Concentration (BrAC) of 0.08 g/dL using the Widmark formula. A total time of 30 minutes will be given for completion of beverage consumption. This will be followed by a breakfast.
Other Names:
  • vodka

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Maximum Ethanol Concentration (Cmax)
Time Frame: prior to dosing (-25 minutes), start of dosing (0 minutes), 15 minutes, 30 minutes, 60 minutes, 90 minutes, 120 minutes, 150 minutes, 180 minutes, 240 minutes, 300 minutes, 350 minutes
Cmax will be determined from visual inspection of the concentration-time plots.
prior to dosing (-25 minutes), start of dosing (0 minutes), 15 minutes, 30 minutes, 60 minutes, 90 minutes, 120 minutes, 150 minutes, 180 minutes, 240 minutes, 300 minutes, 350 minutes
Time to Maximum Ethanol Concentration (Tmax)
Time Frame: prior to dosing (-25 minutes), start of dosing (0 minutes), 15 minutes, 30 minutes, 60 minutes, 90 minutes, 120 minutes, 150 minutes, 180 minutes, 240 minutes, 300 minutes, 350 minutes
Tmax will be determined from visual inspection of the concentration-time plots.
prior to dosing (-25 minutes), start of dosing (0 minutes), 15 minutes, 30 minutes, 60 minutes, 90 minutes, 120 minutes, 150 minutes, 180 minutes, 240 minutes, 300 minutes, 350 minutes
Ethanol Elimination Rate: Blood samples
Time Frame: prior to dosing (-25 minutes), start of dosing (0 minutes), 15 minutes, 30 minutes, 60 minutes, 90 minutes, 120 minutes, 150 minutes, 180 minutes, 240 minutes, 300 minutes, 350 minutes
Data derived from blood samples.
prior to dosing (-25 minutes), start of dosing (0 minutes), 15 minutes, 30 minutes, 60 minutes, 90 minutes, 120 minutes, 150 minutes, 180 minutes, 240 minutes, 300 minutes, 350 minutes
Ethanol Elimination Rate: Breath tests
Time Frame: prior to dosing (-25 minutes), 30 minutes, 60 minutes, 90 minutes, 120 minutes, 150 minutes, 180 minutes, 240 minutes, 300 minutes, 350 minutes
Data derived from breath alcohol test.
prior to dosing (-25 minutes), 30 minutes, 60 minutes, 90 minutes, 120 minutes, 150 minutes, 180 minutes, 240 minutes, 300 minutes, 350 minutes
Ethanol Elimination Rate: Urine samples
Time Frame: prior to dosing (-25 minutes), 60 minutes, 120 minutes, 180 minutes, 240 minutes, 300 minutes
Data derived from urine samples.
prior to dosing (-25 minutes), 60 minutes, 120 minutes, 180 minutes, 240 minutes, 300 minutes

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Biphasic Alcohol Effects Scale (BAES) Score
Time Frame: 5 minutes, 35 minutes, 65 minutes, 95 minutes, 125 minutes, 185 minutes, 245 minutes, 290 minutes, 340 minutes
The BAES has 2 subscales: Stimulant scored from 0-70 and Sedative scored from 0-70. Higher scores indicate higher stimulant or sedative effects.
5 minutes, 35 minutes, 65 minutes, 95 minutes, 125 minutes, 185 minutes, 245 minutes, 290 minutes, 340 minutes
Risk Perception and Safety Appraisal (RPSA) Score
Time Frame: 5 minutes, 35 minutes, 65 minutes, 95 minutes, 125 minutes, 185 minutes, 245 minutes, 290 minutes, 340 minutes
To quantify cognitive and affective dimensions of risk perception, participants will complete the RPSA questionnaire assessing cognitive and affective risk perception, behavioral risk willingness, metacognitive calibration, and consequence awareness. This RPSA has been designed by the study team to provide a low burden (12-item), repeatable measure of cognitive, affective, and behavioral dimensions of risk perception, and direct quantification of willingness to engage in safety sensitive behavior. Scores range from 0-100 where higher scores indicate increased risk perception.
5 minutes, 35 minutes, 65 minutes, 95 minutes, 125 minutes, 185 minutes, 245 minutes, 290 minutes, 340 minutes
Divided Attention Task (DAT)
Time Frame: prior to dosing (-20 minutes), 10 minutes, 100 minutes, 220 minutes
Participants will be asked to complete a computer-based DAT on a laptop in their room. The DAT requires participants to track a moving stimulus on a computer screen while simultaneously monitoring numbers located in the corners of the screen. Participants must respond to target numbers as they appear, and the task quantifies the mean distance of the mouse cursor from the center of the target stimulus.
prior to dosing (-20 minutes), 10 minutes, 100 minutes, 220 minutes
Digital Symbol Substitution Task (DSST)
Time Frame: prior to dosing (-20 minutes), 10 minutes, 100 minutes, 220 minutes
Participants will be asked to complete a computer-based DSST on a laptop in their room. The DSST asks participants to recreate patterns of various shapes presented on a computer screen using the keyboard. The total number of correct patterns are recorded within 90 seconds.
prior to dosing (-20 minutes), 10 minutes, 100 minutes, 220 minutes
Paced Serial Addition Task (PSAT)
Time Frame: prior to dosing (-20 minutes), 10 minutes, 100 minutes, 220 minutes
Participants will be asked to complete a computer-based PSAT on a laptop in their room. The PSAT has participants view a string of single-digit numbers and calculate the sum of the two most recently presented numbers. The total number of correct trials out of 90 will be recorded.
prior to dosing (-20 minutes), 10 minutes, 100 minutes, 220 minutes

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Wisconsin, Madison

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Heather Barkholtz, PhD, UW School of Pharmacy
  • Principal Investigator: Michael Chen, MD, UW School of Medicine and Public Health

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
October 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
March 1, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
March 1, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
August 5, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 5, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
August 11, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
August 11, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 5, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 2026-1120
  • Protocol Version 7/20/26 (Other Identifier: UW Madison)
  • Pharmacy | Pharmacy Practice (Other Identifier: UW Madison)
  • ICTR TBCR Pilot Award (Other Identifier: UW Madison)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Data, including transcriptions of audio-recordings of the driving simulator experiments and biological specimens, will be stored for future use. The original digital audio recordings will not be banked for future use, only the transcription documents containing only experiment-relevant words spoken by the participant will be kept. Only members of the study team will have access to the data and specimens. Prior to banking, identifiers (including linking codes) will be removed from the data and biological specimens. Since identifiers will be removed from the data and biological specimens, participants will not be able to withdraw their banked data and specimens from future research use. Data will be released only as anonymized aggregates after careful consideration and approval of one of the study PIs. No genetic testing will take place on any banked biological specimen.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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