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The Effects of GABA Enhancing Medications on Individuals Addicted to Cocaine - 3

This study has been terminated.
(Study has been completed)
National Institute on Drug Abuse (NIDA)
Information provided by (Responsible Party):
Mehmet Sofuoglu, Yale University Identifier:
First received: September 1, 2005
Last updated: July 7, 2015
Last verified: July 2015
Gamma-aminobutyric acid (GABA) is a type of neurotransmitter, which is a chemical that transmits information within and from the brain to all parts of the body. By lowering the level of another neurotransmitter called dopamine, GABA may have the ability to diminish cocaine cravings in addicts. The purpose of this study is to gather information on the interaction between cocaine and selected GABA enhancing medications in individuals addicted to cocaine. This may lead to future clinical studies using GABA medications to treat cocaine addiction.

Condition Intervention
Cocaine Abuse Cocaine-Related Disorders Drug: Pregabalin Drug: placebo

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple (Participant, Care Provider, Investigator)
Primary Purpose: Treatment
Official Title: The Effects of GABA Medications on Cocaine Responses in Humans

Resource links provided by NLM:

Further study details as provided by Mehmet Sofuoglu, Yale University:

Primary Outcome Measures:
  • Analog rating scale for drug effects; measured during each experimental session [ Time Frame: one week ]
  • Physiological response to cocaine; measured during each experimental session [ Time Frame: one week ]

Enrollment: 72
Study Start Date: September 2004
Study Completion Date: September 2006
Primary Completion Date: September 2006 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: pregabalin
pregabalin compared to placebo
Drug: Pregabalin
pregabalin compared to placebo
Other Name: lyrica
Placebo Comparator: Placebo
Placebo compared to pregabalin
Drug: placebo
sugar pill compared to pregabalin
Other Name: sugar pill

Detailed Description:

GABA is an inhibitory neurotransmitter that is found primarily in the brain. High GABA levels result in low levels of dopamine, another neurotransmitter that is the brain's "feel good" chemical and which plays a primary role in cocaine drug addiction. Cravings for cocaine can be reduced by lowering dopamine levels. This makes GABA-altering medications a potential treatment for cocaine addiction. This study will involve five GABA enhancing medications: tiagabine, topiramate, valproic acid, baclofen, and progesterone. The purpose of the study is to evaluate the interaction between GABA medications and cocaine in terms of safety and craving responses. In turn, these findings may guide future cocaine pharmacotherapy trials.

This 6-day inpatient study will begin with an orientation session to familiarize participants with study procedures. The evening of Day 1, all participants will receive placebo medication. On Days 2 through 4, participants will receive one of five GABA medications. The GABA medications will be given in gradually increasing doses to attain therapeutic levels while maintaining safety and minimizing side effects. Three experimental cocaine sessions will take place; one while the participants are receiving the placebo medication and two while the participants are receiving the GABA medications. During these sessions, cocaine will be administered intravenously in three increasing doses, each separated by 30-minute intervals. This will allow the participants' subjective and physiological responses during cocaine administration to return to baseline levels before the next dose. Blood will be drawn after each dose; heart rate, blood pressure, and an ECG will be monitored throughout the sessions. At the end of each session, questionnaires will be administered to assess the effects of cocaine and related mood states, as well as allow the participants to report any adverse events, depression, craving, or withdrawal symptoms.

This study is now closed and published.


Ages Eligible for Study:   18 Years to 45 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Meets DSM-IV criteria for cocaine dependence
  • History of smoked or intravenous cocaine use on average of at least once a week over a 6 month period
  • Positive urine test for cocaine
  • No current medical problems
  • Normal electrocardiogram
  • If female, willing to use contraception throughout the study

Exclusion Criteria:

  • Seeking treatment for cocaine dependence
  • Current major psychiatric illness, including mood disorder, psychotic disorder, or anxiety disorder
  • Current dependence on alcohol or any drugs other than cocaine or nicotine
  • History of major medical illness, including liver disease, suspected or known cancer, thrombophlebitis, or other medical conditions that are considered unsafe for study participants by the investigator
  • Known allergy to study medications
  • Pregnant or breastfeeding
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT00142883

United States, Connecticut
VA Connecticut Healthcare System
West Haven, Connecticut, United States, 06516
Sponsors and Collaborators
Yale University
National Institute on Drug Abuse (NIDA)
Principal Investigator: Thomas R Kosten, MD Yale University
  More Information

Responsible Party: Mehmet Sofuoglu, Principle Investigator, Yale University Identifier: NCT00142883     History of Changes
Other Study ID Numbers: NIDA-18197-3
P50DA018197-03 ( U.S. NIH Grant/Contract )
DPMC ( Other Identifier: NIDA )
Study First Received: September 1, 2005
Last Updated: July 7, 2015

Keywords provided by Mehmet Sofuoglu, Yale University:
addiction, crack, cocaine

Additional relevant MeSH terms:
Cocaine-Related Disorders
Substance-Related Disorders
Chemically-Induced Disorders
Mental Disorders
Sensory System Agents
Peripheral Nervous System Agents
Physiological Effects of Drugs
Calcium Channel Blockers
Membrane Transport Modulators
Molecular Mechanisms of Pharmacological Action
Anti-Anxiety Agents
Tranquilizing Agents
Central Nervous System Depressants
Psychotropic Drugs
Anesthetics, Local
Vasoconstrictor Agents
Dopamine Uptake Inhibitors
Neurotransmitter Uptake Inhibitors
Dopamine Agents
Neurotransmitter Agents processed this record on August 22, 2017