Vilazodone Treatment for Marijuana Dependence

July 8, 2016 updated by: Aimee McRae-Clark, Medical University of South Carolina
Marijuana is the most commonly used illicit drug, yet few clinical trials have evaluated pharmacotherapy treatments for marijuana dependence. This study will evaluate the efficacy of vilazodone for reducing marijuana use in marijuana-dependent adults. A contingency management intervention (CM)and motivational enhancement therapy (MET)will be incorporated to encourage study engagement and retention, and genomic DNA will be extracted to characterize subjects according to polymorphisms of genes potentially relevant to the activity of vilazodone. It is hypothesized that vilazodone combined with MET and CM will reduce the percent of marijuana-positive urine drug screen results in marijuana-dependent individuals as compared to a placebo treatment combined with MET and CM.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

The purpose of this study is to determine if the medication vilazodone is effective in helping frequent marijuana smokers cut down or stop using marijuana. Vilazodone is FDA approved for the treatment of depression- in this study, vilazodone's effect on marijuana dependence is being investigated.

Participation in the study takes 10 visits over a period of approximately two to three months. The first visit is a screening visit to determine if participants are eligible to participate. After the initial assessment visit, the weekly visits take about 30 minutes, with the exception of three therapy sessions which take approximately 60-90 minutes. The three therapy sessions will focus on participant's marijuana use and reasons they may have for stopping or cutting down on use. After completing an initial therapy session, participants will be randomly selected to receive the study medication, either vilazodone or placebo (a capsule that does not contain any active medication). Participants will have weekly study visits with a clinician. At each study visit, they will be asked to fill out forms and answer specific questions concerning their substance use, anxiety symptoms, and feelings in general. They will be providing urine samples to check for illegal drugs of abuse including marijuana and other drugs. They will also have blood samples drawn during to determine if you are taking the medication as directed.

Study Type

Interventional

Enrollment (Actual)

76

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • South Carolina
      • Charleston, South Carolina, United States, 29425
        • Medical University of South Carolina

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

16 years to 63 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Must meet DSM-IV criteria for marijuana dependence
  • Must be between the ages of 18 and 65 years old
  • If female and of childbearing potential, must agree to use acceptable method of birth control for duration of the trial.
  • Cannabis-positive urine drug screen at screening
  • Must consent to random assignment
  • Must be able to read and provide informed consent

Exclusion Criteria:

  • Women who are pregnant, nursing, or plan to become pregnant during course of study
  • Must not have a history of or current psychotic disorder, bipolar disorder, or eating disorder
  • Must not pose a current suicidal or homicidal risk
  • Must not have evidence or history of serious medical disease
  • Must not require concomitant therapy with psychotropic medication or CYP3A4 inhibitors
  • Must not be currently dependent on other substances, with the exception of nicotine;
  • Patients who, in the investigator's opinion, would be unable to comply with study procedures or assessments

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
Experimental: Vilazodone
Flexible dose up to 40 mg capsule daily
Drug: Vilazodone
up to 40 mg capsule daily
Other Names:
  • Viibryd
Placebo Comparator: Placebo
Flexible dose up to 40 mg capsule daily
Drug: Placebo
up to 40 mg capsule daily

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Percent Marijuana-negative Urine Drug Screens (UDS)
Time Frame: 8 weeks
Participants submitted a urine sample weekly. Percentage of marijuana negative urine samples were calculated per group.
8 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Weekly Cannabis Use Sessions
Time Frame: 8 weeks
Self-report of weekly cannabis use sessions was measured using the Time Line Followback, a calendar-based instrument designed to assess substance consumption.
8 weeks
Marijuana Craving and Withdrawal
Time Frame: 8 weeks
The Marijuana Craving Questionnaire (MCQ) is intended to measure marijuana craving in adults. It measures symptoms on four subscales: expectancy, purposefulness, emotionality, and compulsivity. The scale rates individual items from 1 (least craving) - 7 (most craving) with a composite scoring range of 12-84 and possible subscale scoring range of 3-21. It was administered weekly to all participants. Reported here is the mean MCQ purposefulness subscale score across 8 weeks.
8 weeks

Collaborators and Investigators

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

Sponsor

Medical University of South Carolina

Collaborators

National Institute on Drug Abuse (NIDA)

Investigators

  • Principal Investigator: Aimee L McRae-Clark, PharmD, BCPP, Medical University of South Carolina

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

August 1, 2012

Primary Completion (Actual)

August 1, 2015

Study Completion (Actual)

February 1, 2016

Study Registration Dates

First Submitted

April 5, 2012

First Submitted That Met QC Criteria

April 6, 2012

First Posted (Estimate)

April 10, 2012

Study Record Updates

Last Update Posted (Estimate)

August 10, 2016

Last Update Submitted That Met QC Criteria

July 8, 2016

Last Verified

July 1, 2016

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 16488
  • R21DA034089 (U.S. NIH Grant/Contract)

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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