Canadians' use of cannabis for therapeutic purposes since legalization of recreational cannabis: a cross-sectional analysis by medical authorization status.

BACKGROUND: There has been a precipitous decline in authorizations for medical cannabis since non-medical cannabis was legalized in Canada in 2018. This study examines the demographic and health- and medical cannabis-related factors associated with authorization as well as the differences in medical cannabis use, side effects, and sources of medical cannabis and information by authorization status. METHODS: Individuals who were taking cannabis for therapeutic purposes completed an online survey in early 2022. Multivariable logistic regression was used to determine odds ratios (OR) and 95% confidence intervals (CI) of demographic and health- and medical cannabis-related variables associated with holding medical cannabis authorization. The differences in medical cannabis use, side effects, and sources of information by authorization status were determined via t-tests and chi-squared analysis. RESULTS: A total of 5433 individuals who were currently taking cannabis for therapeutic purposes completed the study, of which 2941 (54.1%) currently held medical authorization. Individuals with authorization were more likely to be older (OR ≥ 70 years vs. < 30 years, 4.85 (95% CI, 3.49-6.76)), identify as a man (OR man vs. woman, 1.53 (1.34-1.74)), have a higher income (OR > $100,000/year vs. < $50,000 year, 1.55 (1.30-1.84)), and less likely to live in a small town (OR small town/rural vs. large city, 0.69 (0.59-0.81)). They were significantly more likely to report not experiencing any side effects (29.9% vs. 23.4%; p < 0.001), knowing the amount of cannabis they were taking (32.1% vs. 17.7%; p < 0.001), obtaining cannabis from regulated sources (74.1% vs. 47.5%; p < 0.001), and seeking information about medical cannabis from healthcare professionals (67.8% vs. 48.2%; p < 0.01) than individuals without authorization. CONCLUSIONS: These findings offer insight into the possible issues regarding equitable access to medical cannabis and how authorization may support and influence individuals in a jurisdiction where recreational cannabis is legalized, highlighting the value of a formal medical cannabis authorization process.

Medical cannabis authorization patterns, safety, and associated effects in older adults.

BACKGROUND: Use of medical cannabis is increasing among older adults. However, few investigations have examined cannabis use in this population. METHODS: We assessed the authorization patterns, safety, and effects of medical cannabis in a sub-analysis of 201 older adults (aged ≥ 65 years) who completed a 3-month follow-up during this observational study of patients who were legally authorized a medical cannabis product (N = 67). Cannabis authorization patterns, adverse events (AEs), Edmonton Symptom Assessment Scale-revised (ESAS-r), and Brief Pain Inventory Short Form (BPI-SF) data were collected. RESULTS: The most common symptoms for which medical cannabis was authorized were pain (159, 85.0%) and insomnia (9, 4.8%). At baseline and at the 3-month follow-up, cannabidiol (CBD)-dominant products were authorized most frequently (99, 54%), followed by balanced products (76, 42%), and then delta-9-tetrahydrocannabinol (THC)-dominant products (8, 4.4%). The most frequent AEs were dizziness (18.2%), nausea (9.1%), dry mouth (9.1%), and tinnitus (9.1%). Significant reductions in ESAS-r scores were observed over time in the domains of drowsiness (p = .013) and tiredness (p = .031), but not pain (p = .106) or well-being (p = .274). Significant reductions in BPI-SF scores over time were observed for worst pain (p = .010), average pain (p = .012), and overall pain severity (p = 0.009), but not pain right now (p = .052) or least pain (p = .141). CONCLUSIONS: Overall, results suggest medical cannabis was safe, well-tolerated, and associated with clinically meaningful reductions in pain in this sample of older adults. However, the potential bias introduced by the high subject attrition rate means that all findings should be interpreted cautiously and confirmed by more rigorous studies.

Cannabidiol use and effectiveness: real-world evidence from a Canadian medical cannabis clinic.

BACKGROUND: Cannabidiol (CBD) is a primary component in the cannabis plant; however, in recent years, interest in CBD treatments has outpaced scientific research and regulatory advancement resulting in a confusing landscape of misinformation and unsubstantiated health claims. Within the limited results from randomized controlled trials, and lack of trust in product quality and known clinical guidelines and dosages, real-world evidence (RWE) from countries with robust regulatory frameworks may fill a critical need for patients and healthcare professionals. Despite growing evidence and interest, no real-world data (RWD) studies have yet investigated patients' reports of CBD impact on symptom control in the common expression of pain, anxiety, depression, and poor wellbeing. The objective of this study is to assess the impact of CBD-rich treatment on symptom burden, as measured with a specific symptom assessment scale (ESAS-r). METHODS: This retrospective observational study examined pain, anxiety, depression symptoms, and wellbeing in 279 participants over 18 years old, prescribed with CBD-rich treatment at a network of clinics dedicated to medical cannabis in Quebec, Canada. Data were collected at baseline, 3 (FUP1), and 6 (FUP2) month after treatment initiation. Groups were formed based on symptom severity (mild vs moderate/severe) and based on changes to treatment plan at FUP1 (CBD vs THC:CBD). Two-way mixed ANOVAs were used to assess ESAS-r scores differences between groups and between visits. RESULTS: All average ESAS-r scores decreased between baseline and FUP1 (all ps < 0.003). The addition of delta-9-tetrahydrocannabinol (THC) during the first follow-up had no effect on symptom changes. Patients with moderate/severe symptoms experienced important improvement at FUP1 (all ps < 0.001), whereas scores on pain, anxiety, and wellbeing of those with mild symptoms actually increased. Differences in ESAS-r scores between FUP1 and FUP2 were not statistically different. CONCLUSION: This retrospective observational study suggests CBD-rich treatment has a beneficial impact on pain, anxiety, and depression symptoms as well as overall wellbeing only for patients with moderate to severe symptoms; however, no observed effect on mild symptoms. The results of this study contribute to address the myths and misinformation about CBD treatment and demand further investigation.

The model of care at a leading medical cannabis clinic in Canada.

Medical cannabis access has been legalized in more than 30 countries worldwide and popularity among patients is increasing rapidly. Cannabinoid-based treatments have been shown to be beneficial for several symptoms such as chemotherapy-induced nausea and vomiting, spasticity, chronic pain, intractable seizures and insomnia, yet high-quality clinical trials are still limited. As millions of patients now have legal access to medical cannabis, little information is available about the development of best clinical practices and an effective medical cannabis clinic model. A medical cannabis clinic is an innovative and emergent practice model that may be necessary to bridge the gap between patient and healthcare provider interest and existing barriers to the prescription of medical cannabis treatments, such as limited medical education, lack of high-quality clinical research and challenging or evolving regulatory frameworks. In this paper, we describe the model of care and organization of a dedicated medical cannabis clinic operating in Quebec, Canada since 2014. We share the principles of medical cannabis practice, including the structure of its medical and support team, clinic organisation and procedure guidelines. Key clinic statistics and patient demographics are shared with year by year comparison. Operating since 2014, the clinic has endured a rapidly changing regulatory landscape in Canada, overcoming numerous challenges including medical and social stigma, limited funding, resources and institutional support combined with a high demand for services. To support medical cannabis leaders globally, an important knowledge-sharing is required. The clinic has expanded to a network of four clinic sites across Quebec and offers continuing education and preceptorships to health care providers and trainees as well as research services to both academic and industry partners. The description of the clinic offers guidance on medical cannabis treatment and care and discusses possible solutions to associated challenges. The clinic model of care can be adapted to different healthcare settings and regulatory frameworks; it may assist physicians and health care providers in the development of medical cannabis clinics or the implementation of best practices as medical cannabis access continues to evolve.

Authorization Patterns, Safety, and Effectiveness of Medical Cannabis in Quebec.

Introduction: Despite increasing demand for data, little is known about the authorization patterns, safety, and effectiveness of medical cannabis products. Materials and Methods: We conducted a 2 year observational study of adult patients who were legally authorized a medical cannabis product from a single licensed producer; we captured and analyzed authorized cannabis use patterns by cannabinoid profile (tetrahydrocannabinol [THC]-dominant; cannabidiol [CBD]-dominant; and balanced (THC:CBD) and clinical outcomes using standardized outcome measures every 3 months for 12 months at a network of medical cannabis clinics in Quebec, Canada. Results: We recruited 585 patients (average age 56.5 years), of whom 61% identified as female and 85% reported pain as their primary complaint. Over 12 months, there was a significant increase in the number of products authorized (Z=2.59, p=0.01). The proportion of authorizations for a THC-dominant or CBD-dominant product increased relative to the proportion of authorizations for a balanced (THC:CBD) product (all p<0.01). Symptom improvement over time was observed for pain, tiredness, drowsiness, anxiety, and well-being. Patients authorized THC-dominant products exhibited less symptom improvement for anxiety and well-being relative to those authorized CBD-dominant or balanced (THC:CBD) products. Medical cannabis was well tolerated across all product profiles. Conclusion: These real-world data reveal changes in medical cannabis authorization patterns and suggest that symptom improvement may vary by cannabinoid profile over 12 months of follow-up.

Medical cannabis in supportive cancer care: lessons from Canada.

Medical cannabis, or cannabinoid-based products, continues to grow in popularity globally, driving the evolution of regulatory access frameworks; cancer patients and caregivers often rely on guidance from their physicians regarding cannabinoid-based treatments. But the majority of healthcare practitioners still feel unprepared and insufficiently informed to make reasonable, evidence-based recommendations about medical cannabis. More than 30 countries worldwide have now legalized access to medical cannabis; yet various nations still face arduous regulatory challenges to fulfill the needs of patients, healthcare practitioners, and other medical stakeholders. This has affected the deployment of comprehensive medical cannabis access programs adapted to cultural and social realities. With a 20-year history of legal medical cannabis access and nearly 400,000 registered patients under its federal access program, Canada serves as a model for countries which are developing their regulatory frameworks. The Canadian clinical experience in cannabinoid-based treatments is also a valuable source of lessons for healthcare professionals who wish to better understand the current evidence examining medical cannabis for oncology patients.

Cannabis in palliative care: current challenges and practical recommendations.

Pain and symptom control challenges are common in palliative care, and the search for other therapeutic strategies is ongoing. Unfortunately, patients and their caregivers are receiving little information or support from healthcare providers regarding the increasingly popular cannabinoid-based medicines (CBM). Clinicians, meanwhile, feel understandably perplexed by the discrepancy between the available evidence and the rapid interest in which patients and their families have demonstrated for CBM. There is an urgent need to address the many challenges that are delaying the appropriate integration of CBM into clinical practice, notwithstanding the obvious need for a solid general knowledge of pharmacology, mechanism of action and available clinical evidence supporting its use. The authors will address these challenges and provide practical recommendations regarding patient assessment for the use of CBM. The authors will also make suggestions regarding patient expectations in order to define clear objectives, review the necessary precautions prior to initiating treatment, aid in selecting the appropriate strain and route of administration as well as establishing proper titration and monitoring protocols. The authors will also discuss the lesser known but potentially therapeutic psychoactive effects of cannabis. As this class of therapeutic agents are likely to play a major role in palliative medicine in the near future, clinicians would benefit from familiarizing themselves with CBM and we can expect that patients and their caregivers will appreciate receiving support in their search for safe and effective therapeutic alternatives.

A temporal model of cofilin regulation and the early peak of actin barbed ends in invasive tumor cells.

Cofilin is an important regulator of actin polymerization, cell migration, and chemotaxis. Recent experimental data on mammary carcinoma cells reveal that stimulation by epidermal growth factor (EGF) generates a pool of active cofilin that results in a peak of actin filament barbed ends on the timescale of 1 min. Here, we present results of a mathematical model for the dynamics of cofilin and its transition between several pools in response to EGF stimulation. We describe the interactions of phospholipase C, membrane lipids (PIP(2)), and cofilin bound to PIP(2) and to F-actin, as well as diffusible cofilin in active G-actin-monomer-bound or phosphorylated states. We consider a simplified representation in which the thin cell edge (lamellipod) and the cell interior are represented by two compartments that are linked by diffusion. We demonstrate that a high basal level of active cofilin stored by binding to PIP(2), as well as the highly enriched local milieu of F-actin at the cell edge, is essential to capture the EGF-induced barbed-end amplification observed experimentally.

Complex dynamics of osteoclast formation and death in long-term cultures.

BACKGROUND: Osteoclasts, cells responsible for bone resorption, contribute to the development of degenerative, metabolic and neoplastic bone diseases, which are often characterized by persistent changes in bone microenvironment. We aimed to investigate the dynamics of osteoclast formation and death in cultures that considerably exceeded the length of standard protocol and to design a mathematical model describing osteoclastogenesis. METHODOLOGY/PRINCIPAL FINDINGS: RAW 264.7 monocytic cells fuse to form multinucleated osteoclasts upon treatment with pro-resorptive cytokine RANKL. We have found that in long-term experiments (15-26 days), the dynamics of changes in osteoclast numbers was remarkably complex and qualitatively variable in different experiments. Whereas 19 of 46 experiments exhibited single peak of osteoclast formation, in 27 experiments we observed development of successive waves of osteoclast formation and death. Periodic changes in osteoclast numbers were confirmed in long-term cultures of mouse bone marrow cells treated with M-CSF and RANKL. Because the dynamics of changes in osteoclast numbers was found to be largely independent of monocytes, a two-species model of ordinary differential equations describing the changes in osteoclasts and monocytes was ineffective in recapitulating the oscillations in osteoclast numbers. Following experimental observation that medium collected from mature osteoclasts inhibited osteoclastogenesis in fresh cultures, we introduced a third variable, factor f, to describe osteoclast-derived inhibitor. This model allowed us to simulate the oscillatory changes in osteoclasts, which were coupled to oscillatory changes in the factor f, whereas monocytes changed exponentially. Importantly, to achieve the experimentally observed oscillations with increasing amplitude, we also had to assume that osteoclast presence stimulates osteoclast formation. CONCLUSIONS/SIGNIFICANCE: This study identifies the critical role for osteoclast autocrine regulation in controlling long-term dynamic of osteoclast formation and death and describes the complementary roles for negative and positive feedback mediators in determining the sharp dynamics of activation and inactivation of osteoclasts.