Cannabis Dependence
Conditions
Keywords
cannabis dependence, marijuana dependence, guanfacine
Brief summary
The purpose of this study is to determine whether guanfacine represents a tolerable, potentially effective pharmacotherapy option for cannabis dependence. Interested in seeing whether guanfacine treatment reduces marijuana consumption, withdrawal symptoms, and craving as compared to baseline.
Detailed description
Cannabis use disorders remain the most common illicit drug use disorder and options for treatment remain limited. Compared to other abusable substances, there has been little investigation of pharmacotherapies for cannabis dependence and no effective pharmacotherapy for cannabis dependence has been developed yet. As such, the development of effective cannabis dependence pharmacotherapy is an important unmet public health need. Lofexidine, an alpha-2 agonist, is effective in treating opioid withdrawal and shows promise as cannabis use disorder pharmacotherapy, though its use may be limited by a cumbersome (thrice daily) dosing regimen. An alpha-2-agonist with a longer half-life, such as guanfacine, may have some of the same benefits as lofexidine at comparable doses, but its easier (once daily) dosing regimen may promote compliance and treatment retention. The purpose of this study is therefore to determine whether guanfacine represents a tolerable, potentially effective pharmacotherapy option for cannabis dependence. This pilot study can also provide the basis for subsequently conducting a larger study aimed at determining efficacy with the appropriate randomized, placebo-controlled design.
Interventions
DRUGGuanfacine
Guanfacine, 4mg given once daily
Sponsors
New York State Psychiatric Institute
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 60 Years
Healthy volunteers
No
Inclusion criteria
* Men and women between the ages of 18-60 who meet DSM-IV criteria for current marijuana dependence * Individuals must report using marijuana at least 20 days in the past 30 days and have a positive urine test for THC on the day of study entry. * Individual must describe marijuana as their primary drug of abuse. * Individuals must be capable of giving informed consent and capable of complying with study procedures.
Exclusion criteria
* Meets DSM-IV-TR criteria for schizophrenia, schizoaffective illness, psychotic disorder other than transient psychosis due to drug abuse, major depression, bipolar illness or psychiatric disorders (other than substance abuse) which require psychiatric intervention. * Unstable medication conditions, such as poorly controlled diabetes or hypertension (\>140/90 mmHg), which might make participation hazardous. * Individuals with liver enzyme function tests greater than three times normal, or acute hepatitis * Individuals with a history of a seizure disorder * Individuals with current suicidal risk. * Individuals who are cognitively impaired * Bradycardia (\< 50 beats/minute), hypotension (sitting or standing BP \< 90/50), or symptoms attributable to low BP (i.e. lightheadedness or dizziness on standing). * Nursing mothers and pregnant women. Women of child bearing age will be included in the study provided that they are not pregnant, based on the results of a blood pregnancy test drawn at the time of screening. They must also agree to use a method of contraception with proven efficacy and agree not to become pregnant during the study. To confirm this, urine pregnancy tests will be repeated monthly. Women will be provided a full explanation of the potential dangers of pregnancy while on the study medication. If a woman becomes pregnant, the study medication will be discontinued. * Individuals who are physiologically dependent on any other drugs (excluding nicotine) that would require a medical intervention * Individuals with known sensitivity to alpha-2 Agonists * Individuals with coronary vascular disease as indicated by history or suspected by abnormal ECG or history of cardiac symptoms * Individuals currently being treated with antihypertensive medication, including alpha-2 agonists * Individuals currently taking medications that may interact adversely with guanfacine. * Individuals who are court-mandated to treatment.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Reduction in Mean Number of Days of Cannabis Use Per Week | Daily cannabis use reported during the 8 week trial or the length of the patient's participation | The reduction in cannabis consumption quantified by the number of days of cannabis use per week was assessed, as measured by the Time Line followback, reported week 1 compared to week 8. |
Countries
United States
Participant flow
Recruitment details
Participants responded to newspapers, radio and public service announcements in the New York City area, and reported at least 20 days of use in the past 30 days.
Participants by arm
| Arm | Count |
|---|---|
| Guanfacine Guanfacine, 4mg given once daily
Guanfacine: Guanfacine, 4mg given once daily | 22 |
| Total | 22 |
Baseline characteristics
| Characteristic | Guanfacine |
|---|---|
| Age, Continuous | 36.1 years STANDARD_DEVIATION 10.3 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 2 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 20 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 4 Participants |
| Race (NIH/OMB) Asian | 0 Participants |
| Race (NIH/OMB) Black or African American | 5 Participants |
| Race (NIH/OMB) More than one race | 6 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 2 Participants |
| Race (NIH/OMB) White | 5 Participants |
| Sex: Female, Male Female | 8 Participants |
| Sex: Female, Male Male | 14 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | — / — |
| other Total, other adverse events | 14 / 22 |
| serious Total, serious adverse events | 0 / 22 |
Outcome results
Primary
Reduction in Mean Number of Days of Cannabis Use Per Week
The reduction in cannabis consumption quantified by the number of days of cannabis use per week was assessed, as measured by the Time Line followback, reported week 1 compared to week 8.
Time frame: Daily cannabis use reported during the 8 week trial or the length of the patient's participation
Population: intent-to-treat sample
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Guanfacine | Reduction in Mean Number of Days of Cannabis Use Per Week | week 1 | 4.1 days of use per week | Standard Deviation 0.6 |
| Guanfacine | Reduction in Mean Number of Days of Cannabis Use Per Week | week 8 | 3.1 days of use per week | Standard Deviation 0.9 |