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Behavioral Therapy Combined With Carbidopa/Levodopa for the Treatment of Cocaine Dependence

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
ClinicalTrials.gov Identifier: NCT00218075
Recruitment Status : Completed
First Posted : September 22, 2005
Last Update Posted : January 5, 2016
Information provided by (Responsible Party):

September 16, 2005
September 22, 2005
January 5, 2016
March 2000
October 2007   (Final data collection date for primary outcome measure)
Cocaine use
Same as current
Complete list of historical versions of study NCT00218075 on ClinicalTrials.gov Archive Site
  • Medication compliance
  • treatment retention
  • severity of addiction-related problems
Medication compliance, treatment retention, and severity of addiction-related problems
Not Provided
Not Provided
Behavioral Therapy Combined With Carbidopa/Levodopa for the Treatment of Cocaine Dependence
Behavioral Strategies to Maximize the Efficacy of Pharmacotherapy for Cocaine Dependence: Relapse Prevention With Contingency Management Procedures
Cocaine dependence is a major public health problem; an effective primary treatment for cocaine dependent individuals has yet to be found. The purpose of this study is to examine the effectiveness of levodopa and carbidopa in treating cocaine dependent individuals. In addition, this study will examine the effects of incentive rewards for treatment compliance.

Cocaine is a strong central nervous system stimulant that is widely abused throughout the United States. Due to its widespread use, it is important to develop an effective treatment for cocaine dependence. Levodopa is a medication that is used alone or in combination with carbidopa to treat Parkinson's disease. The purpose of this study is to determine the possible interactions between behavioral interventions and carbidopa/levodopa in order to treat cocaine dependent individuals.

This study will last 12 weeks and will involve two phases. The first phase will include three therapy conditions: 1) clinical management only, 2) clinical management and relapse prevention therapy, and 3) clinical management, relapse prevention therapy, and contingency management. All of the conditions in the first phase will be evaluated incrementally under active and placebo conditions while participants receive carbidopa/levodopa.

The second phase of the study will examine the contingency management procedure applications. Each of the three contingency management procedure applications targets specific behaviors that, when reinforced, may interact with carbidopa/levodopa to produce clinical benefits. Participants will receive relapse prevention therapy combined with a contingency management procedure that targets clinic attendance, medication compliance, and cocaine abstinence. Study visits will occur weekly throughout the study. In addition, participants will complete a one-year follow-up visit.

Phase 2
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double
Primary Purpose: Treatment
  • Cocaine Abuse
  • Cocaine-Related Disorders
  • Drug: Levodopa
  • Drug: Carbidopa
  • Behavioral: Clinical Management
  • Behavioral: Relapse Prevention Therapy
  • Behavioral: Contingency Management
Not Provided
Not Provided

*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
October 2007
October 2007   (Final data collection date for primary outcome measure)

Inclusion Criteria:

  • Meets DSM-IV criteria for current cocaine dependence
  • Provides at least one positive urine test for cocaine during study screening
  • Good general health, based on a physical exam, lab tests, and an electrocardiogram
  • Reads and writes English at a sixth grade level

Exclusion Criteria:

  • Current Axis I depressive, psychotic, or anxiety disorder
  • Currently in jail
  • Pregnant or breastfeeding
  • Requires certain medications
Sexes Eligible for Study: All
18 Years to 55 Years   (Adult)
Contact information is only displayed when the study is recruiting subjects
United States
P50DA009262 ( U.S. NIH Grant/Contract )
Not Provided
Not Provided
Not Provided
Joy Schmitz, The University of Texas Health Science Center, Houston
The University of Texas Health Science Center, Houston
  • National Institute on Drug Abuse (NIDA)
  • University of Texas
Principal Investigator: John Grabowski, PhD University of Texas
The University of Texas Health Science Center, Houston
January 2016

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP