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- Page navigation anchor for RE: Youth tetrahydrocannabinol (THC) vaping and drivingRE: Youth tetrahydrocannabinol (THC) vaping and driving
This review is an excellent contribution to cannabis and traffic accident prevention research. However, reviews ‘lack of focus and information on youth tetrahydrocannabinol (THC) vaping and driving'. Recently, Canada has approved cannabis for medicinal and non-medicinal use. These changes have also spawned novel cannabis products and formulations including THC vape products (2). Vaporization is an increasingly popular method for cannabis administration, among youths. According to recent research youth cannabis use is increasing in Canada. Vaporization is an increasingly popular method for cannabis administration, among youths (3, 4).
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It should be noted that during 2019-2020, both CMAJ and BC Medical Journal reported serious cases of e-cigarette-related lung injury. These cases were predominantly related to THC vaping. Evidence from the recent US/Canada outbreak of e-cigarette, or vaping, associated lung injury (EVALI)-cases of life-threatening pulmonary illnesses caused by THC-containing vaping products. The Government advise that the Canadians should not use vaping products that contain cannabis (According to a recent Canadian Pediatric Society position statement-usually with higher concentrations of THC than traditional dried cannabis)- https://www.cps.ca/en/documents/position/protecting-children-and-adolesc...)-...Competing Interests: None declared.References
- Sarah B. Windle, Crystal Sequeira, Kristian B. Filion, et al. Impaired driving and legalization of recreational cannabis. CMAJ 2021;193:E481-E485.
- (2). Spindle TR, Cone EJ, Schlienz NJ, et al. Acute Effects of Smoked and Vaporized Cannabis in Healthy Adults Who Infrequently Use Cannabis: A Crossover Trial. JAMA Netw Open. 2018;1(7):e184841. doi:10.1001/jamanetworkopen.2018.4841.
- (3). Fataar F, Hammond D. The Prevalence of Vaping and Smoking as Modes of Delivery for Nicotine and Cannabis among Youth in Canada, England and the United States. Int J Environ Res Public Health. 2019 Oct 25;16(21):4111. doi: 10.3390/ijerph16214111. PMID
- (4). Stanwick R. E-cigarettes: Are we renormalizing public smoking? Reversing five decades of tobacco control and revitalizing nicotine dependency in children and youth in Canada. Paediatr Child Heal, 2015;20(2):101-05.
- (5). Chadi N, Minato C, Stanwick R. Cannabis vaping: Understanding the health risks of a rapidly emerging trend. Paediatr Child Health. 2020 Jun;25(Suppl 1):S16-S20. doi: 10.1093/pch/pxaa016. Epub 2020 Jun 15. PMID: 33390752; PMCID: PMC7757764.
- Page navigation anchor for RE: Residual blood THC levelsRE: Residual blood THC levels
We read your recent review article with interest. However, the article lacks information to guide appropriate legislative revisions and current legislative enhancement strategies to prevent THC and driving in Canada. This is mainly due to lack of accurate information regarding chronic cannabis users and their residual blood THC levels.
Our recent systematic review examined studies on blood THC levels in heavy cannabis users following monitored abstinence of at least 4 hours. The findings of our review suggest that chronic cannabis users may have blood THC levels that persist above the per se limits of 2 ug/L and 5 ug/L despite prolonged abstinence (2). A number of studies reported blood THC levels above 2 ug/L that could persist up to 6 days despite abstinence, with the longest reported duration being 30 days (2, 3). In addition, high THC levels of above 5 ug/L over several days is also a significant finding that informs our knowledge of blood cannabinoid concentrations in heavy users during sustained abstinence.
The current interpretation of THC levels in long-term cannabis users may need to be reconsidered based on the evidence that THC levels may be higher and persist for longer than previously described. Some studies have reported a rapid fall in blood THC levels within an hour or two within smoking and a prolonged terminal elimination phase. During the latter, the blood THC concentrations fall to a residual level of up to 2 to 3 ug/L and decline slowly...
Show MoreCompeting Interests: None declared.References
- (1). Sarah B. Windle, Crystal Sequeira, Kristian B. Filion, et al. Impaired driving and legalization of recreational cannabis. CMAJ 2021;193:E481-E485.
- (2). Peng YW, Desapriya E, Chan H, R Brubacher J. "Residual blood THC levels in frequent cannabis users after over four hours of abstinence: A systematic review.". Drug Alcohol Depend. 2020 Nov 1;216:108177. doi: 10.1016/j.drugalcdep.2020.108177. Epub 202
- (3)Karschner EL, Swortwood MJ, Hirvonen J, Goodwin RS, Bosker WM, Ramaekers JG, et al. Extended plasma cannabinoid excretion in chronic frequent cannabis smokers during sustained abstinence and correlation with psychomotor performance. Drug Testing & Anal
- (4). Bergamaschi MM, Karschner EL, Goodwin RS, Scheidweiler KB, Hirvonen J, Queiroz RH, Huestis MA. Impact of prolonged cannabinoid excretion in chronic daily cannabis smokers' blood on per se drugged driving laws. Clin Chem. 2013 Mar;59(3):519-26. doi: 1
- Page navigation anchor for RE: Impaired driving and legalization of recreational CannabisRE: Impaired driving and legalization of recreational Cannabis
During my research for my book "Cannabis and Kids" I came across a worrisome study, albeit with only 9 subjects, but the article was in Aviation Space Environmental Medicine Mar 1991 62(3) 221-227 - pilots subjected to a single joint were largely incapable of properly passing flight simulation challenges (7/9 inadequate) 24 HOURS after smoking (and this was with lower potency weed back then) and of the 7, only 1 reported feeling any high. We have a lot of work to do!
Dr. Tom Bell MD CCFP FCFPCompeting Interests: None declared.References
- Sarah B. Windle, Crystal Sequeira, Kristian B. Filion, et al. Impaired driving and legalization of recreational cannabis. CMAJ 2021;193:E481-E485.