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

NCT ID: NCT00713583

Last Updated: 2018-04-23

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: PHASE2
• Total Enrollment: 85 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2008-01-31
• Study Completion Date: 2011-12-31

Brief Summary

Cocaine dependence is a major public health problem and the development of a treatment for this disorder is a priority. To date, treatment interventions based on positive incentive principles have shown the strongest effects for improving substance use outcomes. One such example is contingency management (CM) interventions in which nondrug rewards are used to compete with cocaine. Recent evidence suggests that certain medications improve response to CM interventions, particularly agents that target dopamine reward systems in the brain. A promising dopamine-enhancing medication is levodopa. The study team has observed the strongest effects of levodopa when the medication is administered in the context of CM therapy, perhaps through mechanisms that enhance reward saliency. The proposed study is designed to further evaluate this promising treatment approach. Cocaine dependent outpatients will participate in a randomized, 2-group (levodopa vs. placebo), double-blind clinical trial. CM will be behavioral therapy platform for both treatment groups. The study will test the primary hypothesis that CM+levodopa will be more effective than CM+placebo in reducing cocaine use. This study is expected to validate the usefulness of a new behavioral-pharmacological treatment approach for cocaine dependence.

Conditions

Cocaine Dependence

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: QUADRUPLE

Study Groups

Levodopa pharmacotherapy

Levodopa pharmacotherapy (800mg levodopa and 200mg carbidopa per day), cognitive behavioral therapy (CBT), and contingency management (CM).

Group Type: EXPERIMENTAL

levodopa

Intervention Type: DRUG

800mg levodopa and 200mg carbidopa per day

Cognitive Behavioral Therapy

Intervention Type: BEHAVIORAL

Participants received individual cognitive behavioral therapy (CBT) in 50-minute weekly sessions. These sessions were manual-driven and based on the relapse prevention model proposed by Marlatt and Gordon (1985). Trained masters-level therapists, under the supervision of senior therapists and the principal investigator, worked with participants to teach them how to recognize and cope with risky situations that could influence their cocaine use through self-monitoring of situational craving and drug use stimuli, coping skills training, and lifestyle modifications.

Contingency Management

Intervention Type: BEHAVIORAL

An abstinence-based contingency management (CM) procedure was used. Participants earned vouchers according to the reward schedule recommended by Budney and Higgins (1998), beginning at $2.50 for the first cocaine-negative urine. For each consecutive cocaine-negative urine, voucher values increased by $1.25 with a $10 bonus given for provision of three consecutive cocaine-negative urines within a week. A cocaine-positive urine or failure to provide a scheduled urine sample resulted in a reset of the schedule to the initial value of $2.50. After provision of five negative urines, the voucher returned to the value prior to the reset. Participants were able to redeem their vouchers for small amounts of cash (≤$25) or gift cards for goods and services.

Placebo

Placebo, cognitive behavioral therapy (CBT), and contingency management (CM).

Group Type: PLACEBO_COMPARATOR

Placebo

Intervention Type: DRUG

Placebo

Cognitive Behavioral Therapy

Intervention Type: BEHAVIORAL

Participants received individual cognitive behavioral therapy (CBT) in 50-minute weekly sessions. These sessions were manual-driven and based on the relapse prevention model proposed by Marlatt and Gordon (1985). Trained masters-level therapists, under the supervision of senior therapists and the principal investigator, worked with participants to teach them how to recognize and cope with risky situations that could influence their cocaine use through self-monitoring of situational craving and drug use stimuli, coping skills training, and lifestyle modifications.

Contingency Management

Intervention Type: BEHAVIORAL

An abstinence-based contingency management (CM) procedure was used. Participants earned vouchers according to the reward schedule recommended by Budney and Higgins (1998), beginning at $2.50 for the first cocaine-negative urine. For each consecutive cocaine-negative urine, voucher values increased by $1.25 with a $10 bonus given for provision of three consecutive cocaine-negative urines within a week. A cocaine-positive urine or failure to provide a scheduled urine sample resulted in a reset of the schedule to the initial value of $2.50. After provision of five negative urines, the voucher returned to the value prior to the reset. Participants were able to redeem their vouchers for small amounts of cash (≤$25) or gift cards for goods and services.

Interventions

levodopa

800mg levodopa and 200mg carbidopa per day

Intervention Type: DRUG

Placebo

Placebo

Intervention Type: DRUG

Cognitive Behavioral Therapy

Participants received individual cognitive behavioral therapy (CBT) in 50-minute weekly sessions. These sessions were manual-driven and based on the relapse prevention model proposed by Marlatt and Gordon (1985). Trained masters-level therapists, under the supervision of senior therapists and the principal investigator, worked with participants to teach them how to recognize and cope with risky situations that could influence their cocaine use through self-monitoring of situational craving and drug use stimuli, coping skills training, and lifestyle modifications.

Intervention Type: BEHAVIORAL

Contingency Management

An abstinence-based contingency management (CM) procedure was used. Participants earned vouchers according to the reward schedule recommended by Budney and Higgins (1998), beginning at $2.50 for the first cocaine-negative urine. For each consecutive cocaine-negative urine, voucher values increased by $1.25 with a $10 bonus given for provision of three consecutive cocaine-negative urines within a week. A cocaine-positive urine or failure to provide a scheduled urine sample resulted in a reset of the schedule to the initial value of $2.50. After provision of five negative urines, the voucher returned to the value prior to the reset. Participants were able to redeem their vouchers for small amounts of cash (≤$25) or gift cards for goods and services.

Intervention Type: BEHAVIORAL

Other Intervention Names

Sinemet

Eligibility Criteria

Inclusion Criteria

• between 18 and 60 years of age
• meet Diagnostic and Statistical Manual of Mental Disorders, 4th. Edition (DSM-IV) criteria for current cocaine dependence.
• be in acceptable health on the basis of interview, medical history and physical exam.

Exclusion Criteria

• current DSM-IV diagnosis of any psychoactive substance dependence other than cocaine, marijuana, or nicotine.
• have a DSM-IV axis I psychiatric disorder or neurological disease or disorder requiring ongoing treatment and/or making study participation unsafe.
• have significant current suicidal or homicidal ideation.
• have medical conditions contraindicating levodopa/carbidopa pharmacotherapy. Conditions include severe pulmonary disease (bronchial asthma, emphysema), cardiovascular disease (severe or history of myocardial infarction with residual arrhythmias), narrow angle glaucoma, melanoma, history of peptic ulcer, renal function impairment.
• taking medications known to have significant drug interactions with levodopa/carbidopa (e.g., monoamine oxidase (MAO) inhibitors, anticonvulsants, haloperidol, phenothiazines, selegiline, anesthetics).
• currently or recently (last 3 months) treated for substance use or another psychiatric condition.
• having conditions of probation or parole requiring reports of drug use to officers of the court.
• impending incarceration.
• pregnant or nursing for female patients.
• inability to read, write, or speak English.

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 60 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

National Institute on Drug Abuse (NIDA)

NIH

Sponsor Role: collaborator

The University of Texas Health Science Center, Houston

OTHER

Sponsor Role: lead

Responsible Party

Joy Schmitz

Professor - Psychiatry, Behavioral Sciences

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Joy M Schmitz, PhD

Role: PRINCIPAL_INVESTIGATOR

University of Texas at Houston

Locations

The University of Texas Health Science Center at Houston

Houston, Texas, United States

Countries

United States

Other Identifiers

1R01DA023608-01

Identifier Type: NIH

Identifier Source: secondary_id

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R01DA023608-01

Identifier Type: NIH

Identifier Source: secondary_id

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DPMCDA

Identifier Type: OTHER

Identifier Source: secondary_id

1R01DA023608-01

Identifier Type: NIH

Identifier Source: org_study_id

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