Comparison Between Marijuana Smoked in Cigarette Paper Versus Cigar Paper

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.

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.

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).

Plasma THC levels were analyzed to determine pharmacokinetic differences between marijuana cigarettes vs marijuana blunts.

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 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

Expired carbon monoxide averaged across all post-smoking time points when marijuana was smoked as joints and blunts for all participants.

Heart rate averaged across all post-smoking time points when marijuana was smoked as joints and blunts.

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