Marijuana Dependence
Conditions
Keywords
Baclofen, Marijuana Dependence, Marijuana Withdrawal
Brief summary
The purpose of this study is to determine if baclofen dose-dependently decreases marijuana's direct effects and symptoms of marijuana withdrawal and thus decreases marijuana relapse.
Detailed description
Only a small percentage of dependent-marijuana smokers who are seeking treatment for their marijuana use are able to achieve sustained abstinence. The objective of this study is to investigate the interaction between marijuana and the potential treatment medication, baclofen, with the direct goal of using this information to improve marijuana treatment outcome. GABAB agonists such as baclofen have been shown to attenuate the self-administration of cocaine, heroin, alcohol and nicotine (see Cousins et al., 2002; Haney et al., 2006). Baclofen also appears to decrease withdrawal symptoms in heroin and alcohol abusers (Akhondzadeh et al., 2000; Addolorato et al., 2000). The purpose of this study is to determine if baclofen dose-dependently decreases marijuana's direct effects and symptoms of marijuana withdrawal and thus decreases marijuana relapse in our laboratory model. For the purposes of this model, relapse is defined as a return to marijuana use after a period of abstinence. The study will utilize an inpatient/outpatient, counter-balanced design, with each participant maintained on each of three medication conditions for 16 days: placebo and baclofen (60, 90 mg/day). Participants will begin taking capsules during the outpatient phase so that the dose can be incremented up to the maintenance dose prior to the first inpatient day. Further, clinical studies have shown that baclofen is most effective at decreasing cocaine's effects when administered for several weeks. During the inpatient study phases, participants will have the opportunity to self-administer placebo or active marijuana 6 times per day. This study will provide important information of the effect of baclofen as a potential treatment medication for marijuana dependence.
Interventions
DRUGBaclofen
Baclofen (60mg/day or 90 mg/day): Packaged medication in size 00 opaque capsules with riboflavin filler. Study capsules (0, 20, 30mg) were administered 3 times per day (0900, 1530, 2200).
DRUGMarijuana
Marijuana: Participants each received a single marijuana cigarette (provided by the National Institute on Drug Abuse) at each smoking occasion. Marijuana cigarettes were stored frozen in an airtight container and humidified at room temperature for 24 h prior to use.
DRUGPlacebo
Sponsors
National Institute on Drug Abuse (NIDA)
New York State Psychiatric Institute
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
DOUBLE (Subject, Investigator)
Eligibility
Sex/Gender
ALL
Age
21 Years to 45 Years
Healthy volunteers
Yes
Inclusion criteria
* Current marijuana use: average of 3 marijuana cigarettes at least 4 times per week for the past 4 weeks * Able to perform study procedures * 21-45 years of age * Women practicing an effective form of birth control (condoms, diaphragm, birth control pill, IUD)
Exclusion criteria
* Current, repeated illicit drug use (other than marijuana) * Presence of significant medical illness(e.g., diabetes, cardiovascular disease, hypertension, examination, laboratory clinically significant laboratory abnormalities) * History of heart disease * Request for drug treatment * Current parole or probation * Pregnancy or current lactation * Recent history of significant violent behavior * Major current Axis I psychopathology(e.g., major depressive disorder, bipolar disorder, suicide risk, schizophrenia) * Current use of any prescription or over-the-counter medication
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Measure of Relapse: Change in Money Spent Between Baseline and Relapse Phase | Days 1-3 (Baseline) and Days 6-8 (Relapse Phase) | This is a measure of marijuana self-administration and relapse since each initial puff costs $7 and is a burden to overcome just to smoke. Over each 3 day period, the puffs chosen by each participant is averaged for a single value. |
Countries
United States
Participant flow
Pre-assignment details
13 participants were enrolled, but 10 participants were randomized. Three volunteers (1 female, 2 male) dropped out of the study during the marijuana abstinence phase (two were on baclofen and one was on placebo).
Participants by arm
| Arm | Count |
|---|---|
| All Study Participants Participants received placebo, baclofen (60mg) and baclofen (90mg) and smoked Marijuana (5.3% THC). | 10 |
| Total | 10 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 | FG002 | FG003 | FG004 | FG005 |
|---|---|---|---|---|---|---|---|
| Intervention 1 (8 Days) | Withdrawal by Subject | 0 | 2 | 0 | 0 | 1 | 0 |
Baseline characteristics
| Characteristic | All Study Participants |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 0 Participants |
| Age, Categorical Between 18 and 65 years | 10 Participants |
| Region of Enrollment United States | 10 Participants |
| Sex: Female, Male Female | 1 Participants |
| Sex: Female, Male Male | 9 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk |
|---|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — | — / — |
| other Total, other adverse events | 2 / 13 | 0 / 13 | 0 / 13 |
| serious Total, serious adverse events | 0 / 13 | 0 / 13 | 0 / 13 |
Outcome results
Primary
Measure of Relapse: Change in Money Spent Between Baseline and Relapse Phase
This is a measure of marijuana self-administration and relapse since each initial puff costs $7 and is a burden to overcome just to smoke. Over each 3 day period, the puffs chosen by each participant is averaged for a single value.
Time frame: Days 1-3 (Baseline) and Days 6-8 (Relapse Phase)
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Baclofen 60, Marijuana | Measure of Relapse: Change in Money Spent Between Baseline and Relapse Phase | 7.15 dollars spent on marijuana | Standard Deviation 1.85 |
| Placebo, Marijuana | Measure of Relapse: Change in Money Spent Between Baseline and Relapse Phase | 9.77 dollars spent on marijuana | Standard Deviation 2.3 |
| Baclofen 90, Marijuana | Measure of Relapse: Change in Money Spent Between Baseline and Relapse Phase | 7.25 dollars spent on marijuana | Standard Deviation 2.1 |