Are vaporizers a lower-risk alternative to smoking cannabis?

How have cannabis use and related indicators changed since legalization of cannabis for non-medical purposes? Results of the Canadian Cannabis Survey 2018-2022

BACKGROUND

Cannabis use for non-medical purposes was legalized and regulated in Canada through the Cannabis Act in October 2018. This paper examined trends in use of cannabis for non-medical purposes and related indicators from pre- to post-legalization in Canada (2018-2022).

METHODS

Data from 5 years of the Canadian Cannabis Survey, an annual web-based survey administered to Canadians 16 years of age or older, were used in the analysis (n2018=12,952; n2019=11,922; n2020=10,821; n2021=10,733; n2022=10,048). Cannabis measures include questions about use, types of products, sources, risk perceptions and beliefs, and exposure to public education campaigns and health warnings. Adjusted logistic regression models tested differences in outcomes over time.

RESULTS

Past 12-month cannabis consumption increased among Canadians from 22 % in 2018 to 27 % in 2022 (AOR=1.41;99 % CI:1.28-1.54). Similarly, daily/almost daily (DAD) consumption increased from 5 % in 2018 to 7 % in 2022 (AOR=1.36;99 % CI:1.16-1.59). Consumption of dried flower, hash/kief, and concentrates/extracts (e.g., wax, shatter, budder) decreased since 2018, whereas consumption of edibles, beverages and vape pens/cartridges increased (p < 0.001). Legal purchasing increased from 4 % in 2018 to 69 % in 2022, while accessing cannabis through social and illegal sources decreased over time (p < 0.001).

CONCLUSION

More Canadians are reporting cannabis consumption since legalization and regulation of cannabis for non-medical purposes, continuing a pre-existing trend despite an increase in awareness of the risks of consuming cannabis. Trends in product use indicate a transition from dried flower and concentrates/extracts towards consumption of cannabis foods, drinks and vape pens/cartridges. The legal market is increasingly displacing the illicit cannabis market in Canada.

Overview: Chronic Pain and Cannabis-Based Medicines

Chronic pain is primarily conceptualized as a disease in its own right when it is associated with emotional distress and functional impairment. Pathophysiologically, dysfunction of the cortico-mesolimbic connectome is of major importance, with overlapping signals in the nociceptive and stress systems. The endocannabinoid system plays an important role in the central processing of nociceptive signals and regulates the central stress response. Clinically, there is moderate evidence that cannabis-based medicines (CBM) can contribute to a significant reduction in pain, especially the associated pain affect, and improvement in physical function and sleep quality in a proportion of patients with chronic pain. The analgesic effect appears to be largely independent of the cause of pain. In this context, CBM preferentially regulates stress-associated pain processing.

Cardiovascular and Respiratory Effects of Cannabis Use by Route of Administration: A Systematic Review

Aim: Knowledge of the cardiovascular and respiratory effects of cannabis use by route of administration is unclear. This evidence is necessary to increase clinical and public health awareness given the recent trend in cannabis legalization, normalization, and surge in the availability and usage of various forms of cannabis products. Methods: Search was conducted in Web of Science, ProQuest, Psych INFO, Scopus, Embase, and Medline databases, and subsequently in the references of retrieved articles. Peer-reviewed articles published between 2009 and 2023, that reported on cardiovascular and respiratory effects of cannabis use by route of administration were included. Studies with no report of the route of administration and combined use of other illicit substances were excluded. The review was guided by Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Results: Of the 1873 articles retrieved, 42 met inclusion criteria encompassing six case reports, 21 reviews, and 15 empirical studies. Four administration routes were identified: smoking, vaping, oral ingestion, and dabbing. Smoking was the most common route of administration and was associated with both respiratory effects, such as bronchitis, dyspnea, and chronic obstructive lung disease, and cardiovascular effects including tachycardia, ventricular arrhythmias, and myocardial infarction. Cannabis edibles were associated with minimal respiratory effects. Tachycardia was the most common cardiovascular effect and was associated with all routes of administration. Conclusion: Cannabis use does cause cardiovascular and respiratory effects, but the conclusion remains tentative of the cardiovascular and respiratory effects by route of administration due to methodological limitations of the studies.

Clinical outcome data of anxiety patients treated with cannabis-based medicinal products in the United Kingdom: a cohort study from the UK Medical Cannabis Registry

RATIONALE

Cannabis-based medicinal products (CBMPs) have been identified as novel therapeutics for generalised anxiety disorder (GAD) based on pre-clinical models; however, there is a paucity of high-quality evidence on their effectiveness and safety.

OBJECTIVES

This study aimed to evaluate the clinical outcomes of patients with GAD treated with dried flower, oil-based preparations, or a combination of both CBMPs.

METHODS

A prospective cohort study of patients with GAD (n = 302) enrolled in the UK Medical Cannabis Registry prescribed oil or flower-based CBMPs was performed. Primary outcomes were changes in generalised anxiety disorder-7 (GAD-7) questionnaires at 1, 3, and 6 months compared to baseline. Secondary outcomes were single-item sleep quality scale (SQS) and health-related quality of life index (EQ-5D-5L) questionnaires at the same time points. These changes were assessed by paired t-tests. Adverse events were assessed in line with CTCAE (Common Terminology Criteria for Adverse Events) v4.0.

RESULTS

Improvements in anxiety, sleep quality and quality of life were observed at each time point (p < 0.001). Patients receiving CBMPs had improvements in GAD-7 at all time points (1 month: difference -5.3 (95% CI -4.6 to -6.1), 3 months: difference -5.5 (95% CI -4.7 to -6.4), 6 months: difference -4.5 (95% CI -3.2 to -5.7)). Thirty-nine participants (12.9%) reported 269 adverse events in the follow-up period.

CONCLUSIONS

Prescription of CBMPs in those with GAD is associated with clinically significant improvements in anxiety with an acceptable safety profile in a real-world setting. Randomised trials are required as a next step to investigate the efficacy of CBMPs.

Exploring Consumer Preferences for Cannabis Vaping Products to Support Public Health Policy: A Discrete Choice Experiment

BACKGROUND

Phase two of cannabis legalisation in Canada brought cannabis vaping products to the market. This decision was controversial due to an outbreak of vaping cannabis use-associated lung injury. This resulted in three provinces banning the sale of cannabis vaping products causing inequitable access. This study sought to explore consumer preferences for cannabis vaping products to inform cannabis policy.

METHODS

We used a discrete choice experiment to explore consumer preferences for attributes of cannabis vaping products. Attributes included type of device, price, tetrahydrocannabinol (THC) potency, vape liquid content, product recommendations and Health Canada regulation. Participants lived in Canada, were aged ≥ 19 years, and had purchased a cannabis vape in the last 12 months. A multinomial logit (MNL) model was used for the base model, and latent class analysis to assess preference sub-groups.

RESULTS

In total, 384 participants completed the survey; the MNL model showed that price and potency were the most important attributes. A three-group latent class model showed that ~ 40% of the sample was driven primarily by Health Canada Regulation and were willing to pay $56 more for a product that was regulated compared to one that was not. About 33% of the sample was driven by price, and 26% was driven by type of device.

CONCLUSION

While regulated status by Health Canada was most important to some consumers (~ 40%), nearly 60% of the sample were willing to make trade-offs in regulated status for products with a lower price. Therefore, policymakers need to consider the broader public health implications of banning cannabis vapes in some regions.

In what settings and social contexts do young adults vape or smoke cannabis? Findings from a web-based diary pilot study

BACKGROUND

Vaping is an increasingly common mode of cannabis use among young adults. Despite potential to inform targeted prevention, settings and social contexts where young adults vape and/or smoke cannabis have rarely been investigated. We addressed this question in a diverse young adult sample.

METHODS

Data were collected weekly in a web-based daily diary format for six weeks. The analytic sample consisted of the 108 participants (of the 119 enrolled) who used cannabis during the assessment period (mean age = 22.06; 23.78% college students; 65.74% female; 5.56% Asian, 22.22% Black, 16.67% Latinx, 2.78% Multi-racial or Other and 52.77% White). Cannabis use was queried separately for vaping and smoking; respondents reported all settings (14 options) and social contexts (7 options) where they used.

RESULTS

For both vaping and smoking cannabis, the most common settings were home (vaping: 56.97%, smoking: 68.72% [significantly lower for vaping]), friend's home (vaping: 22.49%, smoking: 21.49%), and car (vaping: 18.80%, smoking: 12.99%). The most common social contexts were with friends (vaping: 55.96%, smoking: 50.61%), with significant other (vaping: 25.19%, smoking: 28.53%), and alone (vaping: 25.92%, smoking: 22.62%). Compared to non-students, college students reported vaping on a significantly higher proportion (27.88% vs. 16.50%) of cannabis use days.

CONCLUSIONS

Very similar patterns in settings and social contexts were observed for vaping as smoking and in prevalence of vaping and smoking cannabis across demographic groups. The few notable exceptions have implications for vaping related public health measures: targeting reducing vaping outside the home, particularly in cars, and implementing prevention programming on college campuses.