Vilazodone Treatment for Marijuana Dependence
Study Details
Study Description
Brief Summary
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.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
|
Phase 2 |
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 Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Experimental: Vilazodone Flexible dose up to 40 mg capsule daily |
Drug: Vilazodone
up to 40 mg capsule daily
Other Names:
|
| Placebo Comparator: Placebo Flexible dose up to 40 mg capsule daily |
Drug: Placebo
up to 40 mg capsule daily
|
Outcome Measures
Primary Outcome Measures
- Percent Marijuana-negative Urine Drug Screens (UDS) [8 weeks]
Participants submitted a urine sample weekly. Percentage of marijuana negative urine samples were calculated per group.
Secondary Outcome Measures
- Weekly Cannabis Use Sessions [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.
- Marijuana Craving and Withdrawal [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.
Eligibility Criteria
Criteria
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
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | Medical University of South Carolina | Charleston | South Carolina | United States | 29425 |
Sponsors and Collaborators
- Medical University of South Carolina
- National Institute on Drug Abuse (NIDA)
Investigators
- Principal Investigator: Aimee L McRae-Clark, PharmD, BCPP, Medical University of South Carolina
Study Documents (Full-Text)
None provided.More Information
Publications
None provided.- 16488
- R21DA034089
Study Results
Participant Flow
| Recruitment Details | Participants recruited between August, 2012 and August, 2014 primarily through media and internet advertisements. |
|---|---|
| Pre-assignment Detail |
| Arm/Group Title | Vilazodone | Placebo |
|---|---|---|
| Arm/Group Description | Flexible dose up to 40 mg capsule daily Vilazodone: 40 mg capsule daily | Flexible dose up to 40 mg capsule daily Placebo: 40 mg capsule daily |
| Period Title: Overall Study | ||
| STARTED | 41 | 35 |
| COMPLETED | 14 | 17 |
| NOT COMPLETED | 27 | 18 |
Baseline Characteristics
| Arm/Group Title | Vilazodone | Placebo | Total |
|---|---|---|---|
| Arm/Group Description | Flexible dose up to 40 mg capsule daily Vilazodone: 40 mg capsule daily | Flexible dose up to 40 mg capsule daily Placebo: 40 mg capsule daily | Total of all reporting groups |
| Overall Participants | 41 | 35 | 76 |
| Age (Count of Participants) | |||
| <=18 years |
0
0%
|
0
0%
|
0
0%
|
| Between 18 and 65 years |
41
100%
|
35
100%
|
76
100%
|
| >=65 years |
0
0%
|
0
0%
|
0
0%
|
| Sex: Female, Male (Count of Participants) | |||
| Female |
11
26.8%
|
5
14.3%
|
16
21.1%
|
| Male |
30
73.2%
|
30
85.7%
|
60
78.9%
|
| Region of Enrollment (participants) [Number] | |||
| United States |
41
100%
|
35
100%
|
76
100%
|
Outcome Measures
| Title | Percent Marijuana-negative Urine Drug Screens (UDS) |
|---|---|
| Description | Participants submitted a urine sample weekly. Percentage of marijuana negative urine samples were calculated per group. |
| Time Frame | 8 weeks |
Outcome Measure Data
| Analysis Population Description |
|---|
| [Not Specified] |
| Arm/Group Title | Vilazodone | Placebo |
|---|---|---|
| Arm/Group Description | Flexible dose up to 40 mg capsule daily Vilazodone: up to 40 mg capsule daily | Flexible dose up to 40 mg capsule daily Placebo: up to 40 mg capsule daily |
| Measure Participants | 41 | 35 |
| Measure Urine samples | 328 | 280 |
| Number [percentage of UDS] |
5.5
|
3.6
|
| Title | Weekly Cannabis Use Sessions |
|---|---|
| Description | Self-report of weekly cannabis use sessions was measured using the Time Line Followback, a calendar-based instrument designed to assess substance consumption. |
| Time Frame | 8 weeks |
Outcome Measure Data
| Analysis Population Description |
|---|
| [Not Specified] |
| Arm/Group Title | Vilazodone | Placebo |
|---|---|---|
| Arm/Group Description | Flexible dose up to 40 mg capsule daily Vilazodone: 40 mg capsule daily | Flexible dose up to 40 mg capsule daily Placebo: 40 mg capsule daily |
| Measure Participants | 41 | 35 |
| Mean (95% Confidence Interval) [weekly cannabis sessions] |
10
|
9.9
|
| Title | Marijuana Craving and Withdrawal |
|---|---|
| Description | 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. |
| Time Frame | 8 weeks |
Outcome Measure Data
| Analysis Population Description |
|---|
| [Not Specified] |
| Arm/Group Title | Vilazodone | Placebo |
|---|---|---|
| Arm/Group Description | Flexible dose up to 40 mg capsule daily Vilazodone: 40 mg capsule daily | Flexible dose up to 40 mg capsule daily Placebo: 40 mg capsule daily |
| Measure Participants | 41 | 35 |
| Mean (95% Confidence Interval) [units on a scale] |
8.9
|
11.3
|
Adverse Events
| Time Frame | ||||
|---|---|---|---|---|
| Adverse Event Reporting Description | ||||
| Arm/Group Title | Vilazodone | Placebo | ||
| Arm/Group Description | Flexible dose Vilazodone: up to 40 mg capsule daily | Flexible dose Placebo: up to 40 mg capsule daily | ||
All Cause Mortality |
||||
| Vilazodone | Placebo | |||
| Affected / at Risk (%) | # Events | Affected / at Risk (%) | # Events | |
| Total | / (NaN) | / (NaN) | ||
Serious Adverse Events |
||||
| Vilazodone | Placebo | |||
| Affected / at Risk (%) | # Events | Affected / at Risk (%) | # Events | |
| Total | 0/41 (0%) | 0/35 (0%) | ||
Other (Not Including Serious) Adverse Events |
||||
| Vilazodone | Placebo | |||
| Affected / at Risk (%) | # Events | Affected / at Risk (%) | # Events | |
| Total | 25/41 (61%) | 28/35 (80%) | ||
| Gastrointestinal disorders | ||||
| Diarrhea | 5/41 (12.2%) | 10 | 3/35 (8.6%) | 3 |
| Nausea | 13/41 (31.7%) | 17 | 5/35 (14.3%) | 8 |
| Other GI | 3/41 (7.3%) | 3 | 1/35 (2.9%) | 1 |
| Vomiting | 5/41 (12.2%) | 8 | 0/35 (0%) | 0 |
| General disorders | ||||
| Allergies | 1/41 (2.4%) | 1 | 4/35 (11.4%) | 5 |
| Other | 10/41 (24.4%) | 17 | 10/35 (28.6%) | 13 |
| Musculoskeletal and connective tissue disorders | ||||
| Musculoskeletal | 5/41 (12.2%) | 7 | 6/35 (17.1%) | 6 |
| Nervous system disorders | ||||
| Dizzy/lightheaded | 4/41 (9.8%) | 5 | 2/35 (5.7%) | 2 |
| Dream disturbance | 3/41 (7.3%) | 3 | 1/35 (2.9%) | 1 |
| Headache | 8/41 (19.5%) | 12 | 4/35 (11.4%) | 10 |
| Insomnia | 4/41 (9.8%) | 5 | 5/35 (14.3%) | 5 |
| Respiratory, thoracic and mediastinal disorders | ||||
| Upper Respiratory Infection | 1/41 (2.4%) | 1 | 7/35 (20%) | 7 |
| Congestion | 4/41 (9.8%) | 4 | 9/35 (25.7%) | 9 |
Limitations/Caveats
More Information
Certain Agreements
Principal Investigators are NOT employed by the organization sponsoring the study.
There is NOT an agreement between Principal Investigators and the Sponsor (or its agents) that restricts the PI's rights to discuss or publish trial results after the trial is completed.
Results Point of Contact
| Name/Title | Aimee McRae-Clark, PharmD |
|---|---|
| Organization | MUSC |
| Phone | 843-792-5216 |
| mcraeal@musc.edu |
- 16488
- R21DA034089