Vaping THC From Electronic Cigarettes
Condition: Marijuana Dependence
MeSH terms: Marijuana Abuse
Study type: Interventional
Phase: Phase 3

Summary: 
      This study aims to understand THC pharmacology and the safety of cannabis vaping, including
      the pharmacology and safety of co-administration of nicotine and THC. The study is designed
      as a within-subjects single-blinded crossover study. Fourteen smokers of tobacco cigarettes
      and cannabis will switch between three conditions, namely: (a) vaping cannabis leaf, (b)
      vaping tobacco containing nicotine and (c) vaping a combination of cannabis leaf and tobacco
      containing nicotine. All participants will vape each product with the PAX loose-leaf
      vaporizer. The study will be conducted during three outpatient visits separated by at least
      48 hours. The order of treatment (cannabis leaf, tobacco with nicotine, cannabis leaf &
      tobacco with nicotine) will be counterbalanced between subjects. Subjects will be blinded to
      the content of the vaporizer on the study day but will be told during screening that they
      will vape cannabis alone, tobacco alone, and cannabis plus tobacco with nicotine.
    

Detailed description: 
      Electronic cigarettes (e-cigarettes) have proliferated at a rapid rate since their
      introduction into the US market in 2007, and their use as a form of nicotine delivery far
      outpaced the science base. Although the design of these devices continues to evolve, we have
      previously described nicotine intake, systemic retention, pharmacokinetics, and vaping
      behavior associated with self-administration of e-cigarettes. We demonstrated that while the
      shape of the plasma nicotine concentration-time curve for e-cigarettes is similar to tobacco
      cigarettes, the maximum plasma nicotine concentration is, on average, lower for e-cigarettes.
      During ad libitum access, e-cigarettes were vaped intermittently in groups of 2-5 puffs or
      single puffs such that plasma nicotine levels rose gradually and peaked at the end of the
      90-minute session. This differs from the rapid increase in plasma nicotine observed during
      controlled use of e-cigarettes or during tobacco cigarette smoking. Taken together, these
      results indicate that e-cigarettes have the potential to produce and sustain nicotine
      addiction but their use and abuse liability may differ from tobacco cigarettes.

      The study is designed as a within-subjects, single-blinded crossover study. Fourteen smokers
      of tobacco cigarettes and cannabis will switch between three conditions, namely: (a) vaping
      cannabis leaf, (b) vaping tobacco containing nicotine and (c) vaping a combination of
      cannabis leaf and tobacco containing nicotine. All participants will vape each product with
      the PAX loose-leaf vaporizer, which will be purchased by the study team. The cannabis leaf
      will be obtained through the National Institute on Drug Abuse Drug Supply Program. The
      tobacco-containing nicotine, used in conditions (b) and (c) will come from commercially
      available Marlboro brand cigarettes. The same amount of cannabis or tobacco will be used in
      all conditions.

      The study will be conducted during three outpatient visits separated by at least 48 hours.
      The order of treatment (cannabis leaf, tobacco with nicotine, cannabis leaf & tobacco with
      nicotine) will be counterbalanced between subjects. Subjects will be blinded to the content
      of the vaporizer on the study day but will be told during screening that they will vape
      cannabis alone, tobacco alone, and cannabis plus tobacco with nicotine.

      While scientists struggle to keep up with the latest electronic cigarette trends, the use of
      these devices for cannabis rather than nicotine is increasingly prevalent. Electronic
      cigarette use is not restricted to nicotine. Marijuana, the most widely used illicit drug has
      traditionally been combusted but the vaping of loose-leaf marijuana and THC oil has been
      increasing. the latest national data show that 7.6% of current marijuana users (past 30 days)
      and 9.9% of ever cannabis users (lifetime) administered THC through a vaporizer or electronic
      device (the study did not differentiate between vaporizers and electronic devices like
      e-cigarettes). The prevalence of vaped marijuana or THC is higher among younger adults.
      Prevalence of vaped marijuana/THC among 18-24 and 25-34 year-old ever marijuana users was
      19.3% and 16.3%, respectively, compared to 8.8% for 35-49 year-olds and 5.7% for those 50
      years and over. A recent study also showed high rates of cannabis vaping among high school
      students (18.0% among ever e-cigarette users). Smoking of a combination of tobacco and
      marijuana in cigarette form is also common, particularly in Europe. However, very little is
      known about the safety and pharmacokinetics of this co-administration making it a critical
      area of research.
    

Intervention name(s): Nicotine; Cannabis; PAX Loose Leaf Vaporizer
Intervention type(s): Drug; Drug; Device
Intervention description(s): Participants will vape tobacco leaves with nicotine out of the PAX device.; Participants will vape marijuana leaves with nicotine out of the PAX device.; In all three arms, the participant will be using the same PAX electronic cigarette device. The only difference is whether the participant will be vaping nicotine only, THC only, or nicotine and THC.
Other intervention name(s): Tobacco Leaf; Marijuana Leaf
Intervention MeSH terms: Nicotine
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Single (Participant)
Primary purpose: Other
Keywords: THC; Tobacco; Vaping