Combined Effects of Alcohol and Caffeine

February 23, 2016 updated by: Roland Griffiths, Johns Hopkins University
The purpose of this study is to investigate the effects of caffeine on the self-administration of alcohol. The study will also examine the combined effects of alcohol and caffeine on behavioral performance, participant ratings of behavioral performance, and self-reported subjective effects.

Study Overview

Detailed Description

The purpose of this study is to examine the effects of caffeine on alcohol self-administration. Volunteers will participate in 7 experimental sessions in which they will be given the opportunity to self-administer an alcohol + caffeine or alcohol + caffeine-placebo beverage. The first 6 sessions will involve exposure to the two beverage conditions in mixed order three times each (e.g., A, B, B, A, A, B). The seventh session will be a choice session in which the participant will make a single choice at the beginning of the session about which beverage they will consume that day. In addition to the primary outcomes of quantity of alcohol self-administered and beverage choice, three additional outcomes will be measured including: 1). indirect measures of reinforcing effects (e.g. subjective ratings of liking, well-being, take again); 2). an alcohol-sensitive behavioral measure; and 3). participant ratings of degree of behavioral impairment.

Study Type

Interventional

Enrollment (Actual)

20

Phase

  • 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 Locations

    • Maryland
      • Baltimore, Maryland, United States, 21224
        • Behavioral Pharmacology Research Unit

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

Ages Eligible for Study

21 years to 50 years (Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Very light or moderate consumer of caffeine (either daily or non-daily).
  • Social drinker of alcohol.
  • Has experience in lifetime of heavy alcohol consumption.
  • Read, write, and speak English fluently.

Exclusion Criteria:

  • Serious and unstable illnesses including current hepatic, renal, gastroenterologic, respiratory, cardiovascular (including ischemic heart disease, uncontrolled hypertension, and congestive heart failure), endocrinologic, neurologic (including stroke, transient ischemic attack, subarachnoidal bleeding, brain tumor, encephalopathy, and meningitis), or hematologic disease.
  • Parkinson's disease, seizure disorder, or history of significant head trauma.
  • Current psychiatric illness
  • Pregnant or nursing women or women who are not using an effective means of birth control.

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: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Alcohol self-administration
All participants will participate in seven sessions. In three sessions, each participant will consume a beverage containing alcohol and caffeine. In three separate sessions, participants will consume a beverage containing alcohol and caffeine-placebo. In the final session, all participants may choose which beverage they consume. Participants and research assistants will be blinded to inclusion of caffeine/caffeine-placebo in beverage, but each beverage will be labeled for identification (e.g., A or B).
14 g alcohol per 180 ml total beverage combined with 60 mg caffeine per 180 ml total beverage. The alcohol and caffeine will be mixed in a fruit punch beverage. Participants may self-administer as much beverage as they like with several constraints to assure safety (e.g., participants must stop drinking if their blood alcohol content is above .12 g/dl).
Other Names:
  • Alcohol 190 proof USP
  • Caffeine anhydrous USP
14 g alcohol per 180 ml total beverage combined with 2.2 mg quinine per 180 ml total beverage. The alcohol and quinine will be mixed in a fruit punch beverage. Participants may self-administer as much beverage as they like with several constraints to assure safety (e.g., participants must stop drinking if their blood alcohol content is above .12 g/dl).
Other Names:
  • Alcohol 190 proof USP
  • Quinine hydrochloride dihydrate

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Total beverage consumed
Time Frame: Measured during 2.5 hour drinking period
The primary outcome measure is the total volume of beverage consumed during alcohol + caffeine sessions and alcohol + caffeine-placebo sessions.
Measured during 2.5 hour drinking period

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Circular Lights Task
Time Frame: Approximately every 30 minutes of the 5.5 hour study period
The Circular Lights Task is a measure of behavioral performance
Approximately every 30 minutes of the 5.5 hour study period
The Biphasic Alcohol Effects Scale
Time Frame: Approximately every 30 minutes of the 5.5 hour study period
The Biphasic Alcohol Effects Scale (BAES: Martin et al., 1993) will be repeatedly administered to assess changes in subjective alcohol effects over time. This measure is a commonly used 14-item scale that assesses stimulant (7 items) and sedative (7 items) subjective effects of drugs on a 10-point likert scale
Approximately every 30 minutes of the 5.5 hour study period
Expired air breath alcohol measures
Time Frame: Approximately every 30 minutes during the 5.5 hour study period
Breath alcohol measures will be taken repeatedly in order to assess blood alcohol levels, as well as assure safe discharge. In order to prevent mouth alcohol contamination of breath alcohol measurements, participants will be required to abstain from drinking for 5 minutes before each measurement and to rinse their mouth out thoroughly with water immediately before breath alcohol measures.
Approximately every 30 minutes during the 5.5 hour study period
Subjective ratings 9-point likert scale
Time Frame: Approximately every 30 minutes during the 5.5 hour study period

The following three questions will be asked on a 9-point likert scale:

  1. How much do you like the beverage you have been drinking today?
  2. Rate your sense of "well-being" right now.
  3. How much money would you be willing to pay for a standard mixed drink serving (e.g., 8 oz.) of this beverage at a bar?
Approximately every 30 minutes during the 5.5 hour study period
Subjective ratings visual analogue scale
Time Frame: Approximately every 30 minutes during the 5.5 hour study period

The following two questions will be answered on a visual analogue scale:

  1. How much do you want another drinking right now?
  2. How intoxicated do you feel?
Approximately every 30 minutes during the 5.5 hour study period

Collaborators and Investigators

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

Investigators

  • Principal Investigator: Roland R Griffiths, Ph.D., Johns Hopkins University

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

January 1, 2011

Primary Completion (Actual)

January 1, 2015

Study Completion (Actual)

January 1, 2015

Study Registration Dates

First Submitted

February 1, 2011

First Submitted That Met QC Criteria

February 2, 2011

First Posted (Estimate)

February 3, 2011

Study Record Updates

Last Update Posted (Estimate)

February 24, 2016

Last Update Submitted That Met QC Criteria

February 23, 2016

Last Verified

February 1, 2016

More Information

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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