Effectiveness of Tiagabine for Cocaine Dependence in Methadone-Maintained Individuals - 1

January 11, 2017 updated by: National Institute on Drug Abuse (NIDA)

Tiagabine for the Treatment of Cocaine Dependence in Methadone-Maintained Individuals

Many opioid-dependent individuals are also dependent on cocaine. Methadone is a widely used and effective method for treating opioid dependence. However, it is not effective in treating other drugs of abuse. The purpose of this study is to determine the effectiveness of another drug, tiagabine, for treating cocaine dependence in opioid-dependent individuals already receiving methadone treatment.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

For over 30 years, methadone has been used to treat opioid addiction. Since methadone is effective in reducing withdrawal symptoms, it is used as a method of detoxification for opiate addicts. However, methadone is not effective in treating other drugs of abuse, such as cocaine. Tiagabine is a drug that enhances levels of gamma aminobutyric acid (GABA), a chemical found in the brain and spinal cord. The objective of this study is to determine the effectiveness of tiagabine in modifying cocaine-using behavior and reducing opiate withdrawal symptoms among newly admitted methadone-treated patients.

This 16-week, double-blind, placebo-controlled clinical trial will involve 120 participants who are both cocaine- and opioid- dependent. Participants will be randomly assigned to receive either tiagabine or placebo, while concurrently receiving methadone treatment. Baseline cocaine use will be determined during the first two weeks of treatment. The study will include three overlapping phases. The first phase will include a one-week fixed methadone induction (Week 1), as well as flexible methadone stabilization (Weeks 2-13). Phase two will consist of a 12-week treatment period (Weeks 2-13). This will consist of tiagabine induction and stabilization. Phase three will include a 4-week taper, detoxification, or transfer period (Weeks 14-17). After completion of treatment, a 3-month follow-up visit will occur.

Study Type

Interventional

Enrollment (Actual)

80

Phase

  • Phase 2

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

18 years to 65 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Currently not enrolled in methadone-maintenance treatment
  • Demonstration of current opioid dependence as determined by the study physician, a self-reported history of opioid dependence for one year, and a positive urine test for opiates
  • Current cocaine abuser with self-reported use of cocaine at least 1 time each week within the month prior to study entry, positive urine screen for cocaine, and score greater than 3 on the Severity Dependence Scale
  • Women of childbearing age are eligible under the following conditions: negative pregnancy test at initial screening, adequate contraceptive use throughout the study, monthly pregnancy tests, and acknowledgement of fetal toxicity risks due to medication

Exclusion Criteria:

  • Current diagnosis of other drug or alcohol dependence (other than opiates, cocaine, or tobacco)
  • Serious medical illness (e.g., major heart, kidney, endocrine, or liver disease, or serious neurological disorders, including history of seizures)
  • Current diagnosis of a serious psychiatric illness or history of psychosis, schizophrenia, or bipolar type I disorder
  • Suicidal or homicidal thoughts
  • Currently taking psychotropic medications
  • Women who are pregnant, nursing, refuse to use a reliable form of contraception, or refuse monthly pregnancy testing
  • Greater than 3 times the normal level in liver screening function test (SGOT or SGPT)

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: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Placebo Comparator: 2
Matching placebo
Drug: Tiagabine
The tiagabine group will start receiving tiagabine 4mg in the evening of the first day on week 2. The dose will be titrated every third day, until the target dose of 32mg/day is achieved by week 5. The study medication must be titrated to 32 mg/day or to the subject's maximum tolerated dose (MTD).
Other Names:
  • Gabatril
Experimental: 1
Tiagabine
Drug: Tiagabine
The tiagabine group will start receiving tiagabine 4mg in the evening of the first day on week 2. The dose will be titrated every third day, until the target dose of 32mg/day is achieved by week 5. The study medication must be titrated to 32 mg/day or to the subject's maximum tolerated dose (MTD).
Other Names:
  • Gabatril

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Thrice weekly Urine toxicology
Time Frame: 13 weeks
13 weeks

Secondary Outcome Measures

Outcome Measure
Time Frame
Self reports of cocaine and opioid use.
Time Frame: 13 weeks
13 weeks
Opioid withdrawal symptoms
Time Frame: 13 weeks
13 weeks
Adverse events
Time Frame: 13 weeks
13 weeks
cocaine craving
Time Frame: 13 weeks
13 weeks

Collaborators and Investigators

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

Sponsor

National Institute on Drug Abuse (NIDA)

Investigators

  • Principal Investigator: Gerardo Gonzalez, M.D., Yale 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

December 1, 2004

Study Completion (Actual)

April 1, 2007

Study Registration Dates

First Submitted

August 4, 2005

First Submitted That Met QC Criteria

August 4, 2005

First Posted (Estimate)

August 11, 2005

Study Record Updates

Last Update Posted (Estimate)

January 12, 2017

Last Update Submitted That Met QC Criteria

January 11, 2017

Last Verified

December 1, 2007

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • NIDA-17782-1
  • DPMC (Other Identifier: NIDA)
  • R01-17782-1

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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