Marijuana Dependence
Conditions
Keywords
Marijuana, Comparison between joints and blunts, Pharmacokinetic effects
Brief summary
The purpose of this study is to investigate whether or not marijuana blunts will produce comparable plasma THC levels as marijuana joints and if blunts will produce larger cardiovascular and subjective effects.
Detailed description
There has been a rapid increase in marijuana use during the 1990s, with the most recent generation often smoking marijuana in the form of 'blunts' as opposed to more traditional routes such as in pipes or in cigarette paper. A blunt is made by removing the tobacco from a cigar and replacing it with marijuana (Golub and Johnson, 1999). The cigar wrapper contains tobacco and nicotine, which may interact with the cardiovascular and subjective effects of the marijuana to produce a different set of effects and risks than cigarette paper. Anecdotally, marijuana smokers report that blunts are more potent than joints, yet there have been no controlled studies addressing whether blunts enhance the subjective-effects and health-related consequences of marijuana use. We are proposing to do a within-subject, placebo-controlled study directly comparing the cardiovascular, subjective and pharmacokinetic effects of marijuana smoked in blunts compared to identical quantities of marijuana smoked in cigarette paper. Research volunteers will be current blunt smokers. Each will participate in six, 4-hour outpatient sessions. After baseline data have been collected (heart rate, blood pressure, mood scales, exhaled carbon monoxide, plasma THC and nicotine levels), participants will take 3 puffs, 5 seconds in duration, from a NIDA marijuana cigarette containing 0.0, 1.8 and 3.6% THC or from a blunt containing an equivalent quantity and strength of marijuana. Participants will be blind to the type of marijuana cigarette smoked. We will measure plasma THC and nicotine, subjective mood ratings, and heart rate and blood pressure repeatedly over the course of 180 minutes following smoking. This study is the first controlled investigation of the consequences of this new method of marijuana smoking; the data obtained may be useful in guiding future development of marijuana pharmacotherapy.
Interventions
DRUGMarijuana blunt
Blunts were fabricated by cutting the bottom third off a Dutch Master® cigar, removing all of the cigar tobacco, and replacing it with all of the marijuana contained in a NIDA marijuana cigarette (ca. 800 mg).
DRUGmarijuana cigarette
Marijuana cigarettes were provided by the National Institute on Drug Abuse.
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 blunt marijuana use (minimum of twice/week) drug screen * 21-45 years of age * Practicing an effective form of birth control (condoms, diaphragm, birth control pill, IUD)
Exclusion criteria
* Current, repeated illicit drug use(excluding marijuana) * Heavy cigarette use (\> 10 cigarettes/day) * Presence of significant medical illness (e.g., diabetes, cardiovascular disease, hypertension) * Laboratory tests outside normal limits that are clinically unacceptable to the study physician (BP \> 140/90; hematocrit \< 34 for women, \< 36 for men) * Significant adverse reaction to marijuana * Current parole or probation * Pregnancy or current lactation * History of significant violent behavior * Major current Axis I psychopathology(e.g., mood disorder with functional impairment or suicide risk, anxiety disorder, schizophrenia) * History of heart disease * Current use of any over-the-counter or prescription
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Plasma THC | 180 minutes | Plasma THC levels were analyzed to determine pharmacokinetic differences between marijuana cigarettes vs marijuana blunts. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Subjective Effects on MRF | 180 minutes | Using the Marijuana Rating Form (MRF), subjective effects of Take Again, Liking, and Strong were assessed. The MRF is a visual analog scale allowing patients to indicate how they feel on a 100-mm line anchored with 'not at all' at the left end and 'extremely' at the right end, when prompted by a statement. |
| Subjective Effects on VAS | 180 minutes | Subjective VAS ratings of 'Good Drug Effect' and 'High' averaged across all post-smoking time points when marijuana was smoked as joints and blunts analyzed for all participants. Here, participants indicated how they were feeling on a 100-mm line anchored with 'not at all' at the left end and 'extremely' at the right end, when prompted by a statement |
| Carbon Monoxide | 180 minutes | Expired carbon monoxide averaged across all post-smoking time points when marijuana was smoked as joints and blunts for all participants. |
| Heart Rate | 180 minutes | Heart rate averaged across all post-smoking time points when marijuana was smoked as joints and blunts. |
Countries
United States
Participant flow
Recruitment details
Normal, healthy volunteers ages 21-45 were recruited through newspaper advertisements and those who met inclusion/exclusion criteria after an initial phone screen were invited to the laboratory for further screening.
Pre-assignment details
Prior to enrollment, participants gave written informed consent, received a psychiatric and medical evaluation, and provided a detailed drug use and medical history.
Participants by arm
| Arm | Count |
|---|---|
| Marijuana marijuana blunt (0%, 1.8%, or 3.6% THC) vs. marijuana cigarette (0%, 1.8%, or 3.6% THC) | 24 |
| Total | 24 |
Withdrawals & dropouts
| Period | Reason | FG000 |
|---|---|---|
| Overall Study | Blood could not be drawn. | 2 |
| Overall Study | Did not inhale during smoking procedure. | 3 |
| Overall Study | Pregnancy | 1 |
| Overall Study | Protocol Violation | 5 |
Baseline characteristics
| Characteristic | Marijuana |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 0 Participants |
| Age, Categorical Between 18 and 65 years | 24 Participants |
| Age, Continuous | 25.5 years |
| Region of Enrollment United States | 24 participants |
| Sex: Female, Male Female | 12 Participants |
| Sex: Female, Male Male | 12 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 24 | 0 / 24 |
| other Total, other adverse events | 0 / 24 | 0 / 24 |
| serious Total, serious adverse events | 0 / 24 | 0 / 24 |
Outcome results
Primary
Plasma THC
Plasma THC levels were analyzed to determine pharmacokinetic differences between marijuana cigarettes vs marijuana blunts.
Time frame: 180 minutes
Population: Twenty four participants were included in this within-subjects analysis.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Marijuana Blunt 0% THC | Plasma THC | 6 ng/mL | Standard Deviation 1 |
| Marijuana Blunt 1.8% THC | Plasma THC | 53 ng/mL | Standard Deviation 2 |
| Marijuana Blunt 3.6% THC | Plasma THC | 70 ng/mL | Standard Deviation 2 |
| Marijuana Cigarette 0% THC | Plasma THC | 7 ng/mL | Standard Deviation 1 |
| Marijuana Cigarette 1.8% THC | Plasma THC | 80 ng/mL | Standard Deviation 3 |
| Marijuana Cigarette 3.6% THC | Plasma THC | 98 ng/mL | Standard Deviation 3 |
Secondary
Carbon Monoxide
Expired carbon monoxide averaged across all post-smoking time points when marijuana was smoked as joints and blunts for all participants.
Time frame: 180 minutes
Population: Twenty-four participants were included in this analysis.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Marijuana Blunt 0% THC | Carbon Monoxide | 5.9 ppm | Standard Deviation 0.5 |
| Marijuana Blunt 1.8% THC | Carbon Monoxide | 6.4 ppm | Standard Deviation 0.4 |
| Marijuana Blunt 3.6% THC | Carbon Monoxide | 5.8 ppm | Standard Deviation 0.5 |
| Marijuana Cigarette 0% THC | Carbon Monoxide | 5.5 ppm | Standard Deviation 0.4 |
| Marijuana Cigarette 1.8% THC | Carbon Monoxide | 5.9 ppm | Standard Deviation 0.5 |
| Marijuana Cigarette 3.6% THC | Carbon Monoxide | 5.3 ppm | Standard Deviation 0.4 |
Secondary
Heart Rate
Heart rate averaged across all post-smoking time points when marijuana was smoked as joints and blunts.
Time frame: 180 minutes
Population: Twenty-four participants were included in this analysis.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Marijuana Blunt 0% THC | Heart Rate | 70.5 BPM | Standard Deviation 0.5 |
| Marijuana Blunt 1.8% THC | Heart Rate | 72.5 BPM | Standard Deviation 0.4 |
| Marijuana Blunt 3.6% THC | Heart Rate | 73 BPM | Standard Deviation 0.5 |
| Marijuana Cigarette 0% THC | Heart Rate | 70.5 BPM | Standard Deviation 0.4 |
| Marijuana Cigarette 1.8% THC | Heart Rate | 72 BPM | Standard Deviation 0.5 |
| Marijuana Cigarette 3.6% THC | Heart Rate | 74 BPM | Standard Deviation 0.4 |
Secondary
Subjective Effects on MRF
Using the Marijuana Rating Form (MRF), subjective effects of Take Again, Liking, and Strong were assessed. The MRF is a visual analog scale allowing patients to indicate how they feel on a 100-mm line anchored with 'not at all' at the left end and 'extremely' at the right end, when prompted by a statement.
Time frame: 180 minutes
Population: Twenty four participants were included in this within-subjects analysis.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Marijuana Blunt 0% THC | Subjective Effects on MRF | Liking | 18 Ratings (mm) | Standard Deviation 0.4 |
| Marijuana Blunt 0% THC | Subjective Effects on MRF | Take Again | 23 Ratings (mm) | Standard Deviation 0.5 |
| Marijuana Blunt 0% THC | Subjective Effects on MRF | Strong | 10 Ratings (mm) | Standard Deviation 0.5 |
| Marijuana Blunt 1.8% THC | Subjective Effects on MRF | Liking | 30 Ratings (mm) | Standard Deviation 0.5 |
| Marijuana Blunt 1.8% THC | Subjective Effects on MRF | Take Again | 28 Ratings (mm) | Standard Deviation 0.4 |
| Marijuana Blunt 1.8% THC | Subjective Effects on MRF | Strong | 17 Ratings (mm) | Standard Deviation 0.4 |
| Marijuana Blunt 3.6% THC | Subjective Effects on MRF | Liking | 33 Ratings (mm) | Standard Deviation 0.4 |
| Marijuana Blunt 3.6% THC | Subjective Effects on MRF | Take Again | 36 Ratings (mm) | Standard Deviation 0.5 |
| Marijuana Blunt 3.6% THC | Subjective Effects on MRF | Strong | 29 Ratings (mm) | Standard Deviation 0.5 |
| Marijuana Cigarette 0% THC | Subjective Effects on MRF | Liking | 10 Ratings (mm) | Standard Deviation 0.5 |
| Marijuana Cigarette 0% THC | Subjective Effects on MRF | Take Again | 12 Ratings (mm) | Standard Deviation 0.4 |
| Marijuana Cigarette 0% THC | Subjective Effects on MRF | Strong | 5 Ratings (mm) | Standard Deviation 0.4 |
| Marijuana Cigarette 1.8% THC | Subjective Effects on MRF | Liking | 45 Ratings (mm) | Standard Deviation 0.4 |
| Marijuana Cigarette 1.8% THC | Subjective Effects on MRF | Take Again | 45 Ratings (mm) | Standard Deviation 0.5 |
| Marijuana Cigarette 1.8% THC | Subjective Effects on MRF | Strong | 30 Ratings (mm) | Standard Deviation 0.5 |
| Marijuana Cigarette 3.6% THC | Subjective Effects on MRF | Take Again | 54 Ratings (mm) | Standard Deviation 0.4 |
| Marijuana Cigarette 3.6% THC | Subjective Effects on MRF | Strong | 42 Ratings (mm) | Standard Deviation 0.4 |
| Marijuana Cigarette 3.6% THC | Subjective Effects on MRF | Liking | 55 Ratings (mm) | Standard Deviation 0.5 |
Secondary
Subjective Effects on VAS
Subjective VAS ratings of 'Good Drug Effect' and 'High' averaged across all post-smoking time points when marijuana was smoked as joints and blunts analyzed for all participants. Here, participants indicated how they were feeling on a 100-mm line anchored with 'not at all' at the left end and 'extremely' at the right end, when prompted by a statement
Time frame: 180 minutes
Population: Twenty-four participants were included in this analysis.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Marijuana Blunt 0% THC | Subjective Effects on VAS | Good Drug Effect | 10 Ratings (mm) | Standard Deviation 0.5 |
| Marijuana Blunt 0% THC | Subjective Effects on VAS | High | 7 Ratings (mm) | Standard Deviation 0.4 |
| Marijuana Blunt 1.8% THC | Subjective Effects on VAS | Good Drug Effect | 29 Ratings (mm) | Standard Deviation 0.4 |
| Marijuana Blunt 1.8% THC | Subjective Effects on VAS | High | 10 Ratings (mm) | Standard Deviation 0.5 |
| Marijuana Blunt 3.6% THC | Subjective Effects on VAS | Good Drug Effect | 33 Ratings (mm) | Standard Deviation 0.5 |
| Marijuana Blunt 3.6% THC | Subjective Effects on VAS | High | 20 Ratings (mm) | Standard Deviation 0.4 |
| Marijuana Cigarette 0% THC | Subjective Effects on VAS | Good Drug Effect | 4 Ratings (mm) | Standard Deviation 0.4 |
| Marijuana Cigarette 0% THC | Subjective Effects on VAS | High | 3 Ratings (mm) | Standard Deviation 0.5 |
| Marijuana Cigarette 1.8% THC | Subjective Effects on VAS | Good Drug Effect | 28 Ratings (mm) | Standard Deviation 0.5 |
| Marijuana Cigarette 1.8% THC | Subjective Effects on VAS | High | 23 Ratings (mm) | Standard Deviation 0.4 |
| Marijuana Cigarette 3.6% THC | Subjective Effects on VAS | Good Drug Effect | 37 Ratings (mm) | Standard Deviation 0.4 |
| Marijuana Cigarette 3.6% THC | Subjective Effects on VAS | High | 30 Ratings (mm) | Standard Deviation 0.5 |