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Caffeine and Cocaine

This study has been completed.
National Institute on Drug Abuse (NIDA)
The University of Texas Health Science Center, Houston
Information provided by (Responsible Party):
Frederick Gerard Moeller, Virginia Commonwealth University Identifier:
First received: August 12, 2008
Last updated: January 5, 2016
Last verified: January 2016
This study is being done to find out if medicines that affect a neurotransmitter (chemical messenger) in the brain called adenosine improve behavioral problems that are related to drug abuse. Another purpose of the study is to find out how genes related to adenosine change how people respond to these medicines. More information about how these medicines change behaviors may be helpful to come up with new treatments for drug abuse.

Condition Intervention Phase
Cocaine Dependence
Drug: Caffeine
Drug: Placebo
Phase 1
Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor)
Primary Purpose: Basic Science
Official Title: Experiment 1: Adenosine Receptor A2A Antagonists and Cocaine Dependence

Resource links provided by NLM:

Further study details as provided by Virginia Commonwealth University:

Primary Outcome Measures:
  • impulsivity [ Time Frame: 3 weeks of treatment ]

Secondary Outcome Measures:
  • cocaine positive urines [ Time Frame: 3 weeks of treatment ]
  • cue reactivity [ Time Frame: 3 weeks of treatment ]

Enrollment: 67
Study Start Date: April 2008
Study Completion Date: October 2011
Primary Completion Date: July 2011 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: 1
Drug: Caffeine
300 mg for 7 days; then 600 mg for 7 days; then 900 mg for 7 days; followed by a 3 day taper. all dosing three times per day
Other Name: Vivarin
Placebo Comparator: 2
Drug: Placebo
3 times per day

Detailed Description:

Specific Aims:

Aim 1. To characterize the behavioral and subjective effects of acute caffeine administration in cocaine-dependent subjects, using laboratory measures of impulse control, drug discrimination (with d-amphetamine as the training dose), and subjective effects.

Hypotheses related to Aim 1:

  1. Subjects will show decreases in impulsivity (delay to reward and response inhibition) after acute oral doses of caffeine compared to placebo.
  2. Subjects will show some stimulant-like subjective effects following acute oral doses of caffeine, but not the euphoric effects that would predict abuse potential.
  3. Following training doses of placebo and 20 mg d-amphetamine, oral doses of caffeine will be discriminated as being different than 20 mg d-amphetamine and different from placebo.

Aim 2. To determine the effect of a 2-week trial of oral caffeine on laboratory measures of impulsivity and cue reactivity in cocaine dependent subjects.

Hypothesis related to Aim 2:

  1. Daily caffeine (600 - 900 mg) treatment will decrease impulsivity (delay to reward and response inhibition) compared to placebo.
  2. Daily caffeine (600 - 900 mg) treatment will decrease cocaine related cue reactivity compared to placebo.

Secondary Aims:

Secondary Aim 1. To examine the effect of 2-weeks of treatment with caffeine on cocaine use in cocaine dependent subjects.

Secondary hypothesis 1: Cocaine dependent subjects treated with caffeine will show a significant reduction in cocaine positive urine drug screens compared with cocaine dependent subjects treated with placebo.

Secondary Aim 2. To examine the relationship between gene polymorphisms for the A2A receptor gene and behavioral effects of caffeine Secondary hypothesis 2: Genetic variation in the adenosine A2A receptor gene (ADORA2A) will be associated with the behavioral effects of caffeine.


Ages Eligible for Study:   18 Years to 55 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Subjects who currently meet DSM-IV criteria for cocaine dependence.
  • At least one cocaine positive urine during screening.
  • Current regular consumption of caffeine.
  • Female subjects: a negative pregnancy test.

Exclusion Criteria:

  • Current or past DSM-IV Axis I disorder other than substance abuse/ dependence
  • Any significant non-psychiatric medical illness requiring ongoing medical treatment or which would preclude treatment with d-amphetamine or caffeine
  • Substance dependence other than cocaine within the last 3 months.
  • Positive breath alcohol.
  • Positive urine drug screen for drugs other than cocaine or THC at the time of behavioral testing
  • For female subjects: known pregnancy or a positive pregnancy test or current breast feeding.
  • Diagnosis of Adult Attention Deficit Disorder as determined by: a) meeting DSM-IV criteria for childhood ADHD, b) currently has impairing ADHD symptoms, c) ADHD symptoms can not have remitted at any period since childhood.
  • HIV positive.
  • I.Q. below 70.
  Contacts and Locations
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Please refer to this study by its identifier: NCT00733993

United States, Texas
The University of Texas Health Science Center, Houston
Houston, Texas, United States, 77030
Sponsors and Collaborators
Virginia Commonwealth University
National Institute on Drug Abuse (NIDA)
The University of Texas Health Science Center, Houston
Principal Investigator: Frederick G Moeller, MD The University of Texas Health Science Center, Houston
  More Information

Additional Information:
Responsible Party: Frederick Gerard Moeller, Professor - Division Chair, Addiction Psychiatry, Virginia Commonwealth University Identifier: NCT00733993     History of Changes
Other Study ID Numbers: DA09262  P50DA009262  DPMCDA 
Study First Received: August 12, 2008
Last Updated: January 5, 2016

Keywords provided by Virginia Commonwealth University:
substance abuse

Additional relevant MeSH terms:
Cocaine-Related Disorders
Substance-Related Disorders
Chemically-Induced Disorders
Mental Disorders
Central Nervous System Stimulants
Physiological Effects of Drugs
Phosphodiesterase Inhibitors
Enzyme Inhibitors
Molecular Mechanisms of Pharmacological Action
Purinergic P1 Receptor Antagonists
Purinergic Antagonists
Purinergic Agents
Neurotransmitter Agents
Anesthetics, Local
Central Nervous System Depressants
Sensory System Agents
Peripheral Nervous System Agents
Vasoconstrictor Agents
Dopamine Uptake Inhibitors
Neurotransmitter Uptake Inhibitors
Membrane Transport Modulators
Dopamine Agents processed this record on February 24, 2017