Analysis of Cannabis Smoke Obtained under Different Combustion Conditions

Fehr, Kevin O’Brien; Kalant, H.

doi:10.1139/y72-111

Cited by 41 publications

(18 citation statements)

References 3 publications

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“…It appears that habitual heavy marijuana smokers can increase the amount absorbed and this is attributed to more efficient smoking techniques (12,13). Table 1 indicates some of the variation found by various researchers (12,(16)(17)(18)(19)(20) who investigated the amount of THC lost during smoking, with 69% regarded as the maximum available for absorption via mainstream smoke from a smoking machine (16). However, as much as 50% of the active drug in cigarettes can be lost due to pyrolysis.…”

Section: Absorption Smoked Cannabismentioning

confidence: 99%

Pharmacokinetics of Cannabinoids

McGilveray

2005

Pain Research and Management

166

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Delta-9-tetrahydrocannabinol (∆-9-THC) is the main psychoactive ingredient of cannabis (marijuana). The present review focuses on the pharmacokinetics of THC, but also includes known information for cannabinol and cannabidiol, as well as the synthetic marketed cannabinoids, dronabinol (synthetic THC) and nabilone. The variability of THC in plant material (0.3% to 30%) leads to variability in tissue THC levels from smoking, which is, in itself, a highly individual process. THC bioavailability averages 30%. With a 3.55% THC cigarette, a peak plasma level of 152±86.3 ng/mL occured approximately 10 min after inhalation. Oral THC, on the other hand, is only 4% to 12% bioavailable and absorption is highly variable. THC is eliminated from plasma in a multiphasic manner, with low amounts detectable for over one week after dosing. A major active 11-hydroxy metabolite is formed after both inhalation and oral dosing (20% and 100% of parent, respectively). THC is widely distributed, particularly to fatty tissues, but less than 1% of an administered dose reaches the brain, while the spleen and body fat are long-term storage sites. The elimination of THC and its many metabolites (from all routes) occurs via the feces and urine. Metabolites persist in the urine and feces for several weeks. Nabilone is well absorbed and the pharmacokinetics, although variable, appear to be linear from oral doses of 1 mg to 4 mg (these doses show a plasma elimination half-life of approximately 2 h). As with THC, there is a high first-pass effect, and the feces to urine ratio of excretion is similar to other cannabinoids. Pharmacokineticpharmacodynamic modelling with plasma THC versus cardiac and psychotropic effects show that after equilibrium is reached, the intensity of effect is proportional to the plasma THC profile. Clinical trials have found that nabilone produces less tachycardia and less euphoria than THC for a similar antiemetic response.Key Words: Cannabinoids; Inhalation; Nabilone; Pharmacodynamics; Pharmacokinetics Pharmacocinétique des cannabinoïdesLe delta-9-tétrahydrocannabinol (∆-9-THC) est le principal ingrédient psychoactif du cannabis (marijuana). Le présent article de synthèse s'attarde à la pharmacocinétique du THC, mais inclut également des données sur le cannabinol et le cannabidiol, de même que sur les cannabinoïdes de synthèse sur le marché, soit le dronabinol (THC synthétique) et le nabilone. La variabilité des taux de THC dans la substance végétale (0,3 % à 30 %) donne lieu à des taux tissulaires variables de THC après l'inhalation, qui en soi, est déjà un processus hautement individuel. La biodisponibilité du THC est en moyenne de 30 %. Avec une cigarette dont la teneur en THC est de 3,55 % un pic plasmatique de 152 ± 86,3 ng/mL s'obtient environ 10 minutes après l'inhalation. D'autre part, le THC oral n'est biodisponible que dans une proportion de 4 à 12 % et son absorption est très variable. Le THC est éliminé du plasma de façon multiphasique, de faibles quantités étant décelables encore dans les sept jours suivant ...

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Section: Absorption Smoked Cannabismentioning

confidence: 99%

Pharmacokinetics of Cannabinoids

McGilveray

2005

Pain Research and Management

166

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“…It can also be vaporized [12]. THC is present in smoke inhaled by the user but also in the smoke dispersed in the environment [13][14][15]. This is especially true if the user is using joints and blunts where the smoke billows out of it directly.…”

Section: Pharmacokinetic and Pharmacodynamic Considerationsmentioning

confidence: 99%

Does "Hotboxing?" Get You High and Can You Test Positive? - A Brief Review of Second-Hand Cannabis Exposure, Intoxication and Urine Drug Screens

Gnanasegaram¹,

Ganpat²,

Stanciu³

2017

J Alcohol Drug Depend

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Cannabis use is on the rise with higher and higher potencies of marijuana being cultivated. Current legislatures make it easier, and legal, for users to use, especially around nonusers. When such second-hand smoke occurs in poorly ventilated confinements, nonusers may inhale some of the smoke, resulting in absorption of cannabinoids. Some degree of intoxication may occur but most importantly, detectable levels of the drug in blood and urine. Often screening is used by employers, law enforcement agencies, physicians and substance abuse providers. Clinicians hence need to be mindful of such factors when patients deny use despite positive tests. Here we review available evidence, with emphasis on current data based on today's trends.Clinical background: "I have not smoked marijuana since before I was drafted" 23 year-old NFL player Josh Gordon stated as his explanation for testing positive above the 15 ng/mL THC threshold the NFL considers a failed test. In his appeal he stated he was around individuals using marijuana. His "A" sample tested at 16 ng/mL and his "B" sample tested at 13.63 ng/mL. The two should be consistent since it comes from the same specimen. His legal team was able to dispute the results and reduce his sentence to 8 months as he was the "victim of breathing second hand smoke" (ESPN, 2014).

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“…c. Effects on Pulmonary System Inhaling the smoke of marijuana cigarettes (or  9 -THC) produces acute bronchodilation in healthy subjects and asthmatics, bronchodilation that may last at least one hour (Tashkin et al 1977;Vachon et al, 1973). It is important to note that cannabis smokers have a higher lung cancer risk than tobacco consumers because of the high aromatic hydrocarbons content in marijuana smoke, which has higher concentrations of irritant substances, such as sterols, terpenes, among others (Fehr and Kalant, 1972). Comparing a normal about five times tobacco cigarette with a marijuana cigarette, it is estimated that the latter produces more carboxyhemoglobin, with consequent maintenance increase in the respiratory tract (Benson & Bentley, 1995, Wu et al, 1988.…”

Section: Pharmacodynamic Effectsmentioning

confidence: 99%