Prevalence and self-reported reasons of cannabis use for medical purposes in USA and Canada

Rationale There has been increasing attention on cannabis use for medical purposes, but there is currently a lack of data on its epidemiology. Objectives To examine the epidemiology of self-reported cannabis use for medical purposes by (1) estimating its prevalence, (2) comparing gender and age differences, and (3) investigating what reasons they were used to manage. Methods Participants included 27,169 respondents (aged 16–65) who completed Wave 1 of The International Cannabis Policy Study (ICPS) conducted across Canada and the USA in 2018 via online surveys. Cannabis policy conditions were “US legal–recreational” (legal for both recreational and medical uses), “US legal–medical only”, “US illegal”, and “Canada–medical only”. Results The overall prevalence of self-reported ever cannabis use for medical purposes was 27%, with similar rates by sex and the highest prevalence in young adults. Prevalence was higher in US legal–recreational states (34%) than US illegal states (23%), US legal–medical only states (25%), and Canada (25%). The most common physical health reasons include use to manage pain (53%), sleep (46%), headaches/migraines (35%), appetite (22%), and nausea/vomiting (21%). For mental health reasons, the most common were for anxiety (52%), depression (40%), and PTSD/trauma (17%). There were 11% who reported using cannabis for managing other drug or alcohol use and 4% for psychosis. Conclusions A substantial proportion of the North American population self-reported cannabis use for medical purposes for a variety of medical reasons, including those living in jurisdictions without legal markets. Further research is needed to understand the safety and efficacy of these forms of medical cannabis use.

Medical cannabis use in Thailand after its legalization: a respondent-driven sample survey

Background Many countries now allow the consumption of cannabis or cannabinoids for medical purposes with varying approaches concerning products allowed and the regulatory frameworks prevailing their endowment. On 18 February 2019 Thailand passed legislation allowing the use of cannabis for medical purposes. This study aimed to examine patterns and purposes for consumption of medical cannabis, and consumers’ perceptions and opinions towards benefits and harms of cannabis and related policies in 2019–2020. Methods A cross-sectional study using a respondent-driven sampling (RDS) method was conducted in four sites across Thailand. Participants were 485 adults aged 18 years and over, living in the study region, who had used cannabis for medical purposes within the past 12 months. Face-to-face interviews using a structured questionnaire were used to collect data on (1) demographic characteristics, (2) pattern of consumption, (3) source of information and perception of benefits and harms of medical cannabis, and (4) opinion towards cannabis policies. Data were analyzed using RDS Analyst and presented as percentage and mean with 95% confidence interval (CI). Results Most participants (84.7%, 95% CI [78.9–90.5]) used an oral form of crude oil extract while 9.2% (95% CI [4.1–14.2]) used the raw form. The most common uses were for treatment of cancers (23.3%, 95% CI [16.1–30.4]), neuropsychiatric symptoms (22.8%, 95% CI [17.5–28.0]), and musculoskeletal pains (21.6%, 95% CI [16.7–26.6]). Illegal sources such as underground traders (54.5%, 95% CI [40.8–68.3]), friends and relatives (12.2%, 95% CI [6.2–18.3]), not-for-profit provider groups (5.2%, 95% CI [0.5–10.9]), and clandestine growers or producers (2.9%, 95% CI [0.6–5.3]) were the main suppliers. Most (>80%) perceived cannabis could treat cancers, chronic pains, insomnia, Parkinson’s disease and generalized anxiety disorder. Less than half perceived that cannabis could cause adverse conditions e.g., palpitation, panic, memory impairment and schizophrenic-like psychosis. Most respondents agreed or strongly agreed with the policies regarding permission to use cannabis for medical purposes (95.1%, 95% CI [92.0–98.2]), for the legal sale of medical cannabis products (95.9%, 95% CI [93.7–98.2]), and for people to grow cannabis for medical use (94.2%, 95% CI [91.8–96.5]). However, only two-thirds agreed with policies concerning the sales of cannabis (65.3%, 95% CI [56.9–73.7]) and home-grown cannabis for recreational purposes (61.3%, 95% CI [52.7–69.9]). Conclusion Our study reports the experiences of consumers of medical cannabis in the first year after its legalization in Thailand. Consumers reported various patterns and indications of consumption that were not supported by scientific evidence, but had positive perception of the results of consumption. These findings highlight ongoing policy challenges for Thailand and can be a lesson to be learned for other countries in the region.

A mixed methods analysis of cannabis use routines for chronic pain management

Background The wide heterogeneity of available cannabis products makes it difficult for physicians to appropriately guide patients. In the current study, our objective was to characterize naturalistic cannabis use routines and explore associations between routines and reported benefits from consuming cannabis. Methods We performed a mixed methods analysis of n=1087 cross-sectional survey responses from adults with self-reported chronic pain using cannabis for symptom management in the USA and Canada. First, we qualitatively analyzed responses to an open-ended question that assessed typical cannabis use routines, including administration routes, cannabinoid content, and timing. We then sub-grouped responses into categories based on inhalation (smoking, vaporizing) vs. non-inhalation (e.g., edibles). Finally, we investigated subgroups perceptions of how cannabis affected pain, overall health, and use of medications (e.g., substituting for opioids, benzodiazepines). Substitutions were treated as a count of medication classes, while responses for both pain and health were analyzed continuously, with − 2 indicating health declining a lot or pain increasing a lot and 2 indicating that health improved a lot or pain decreased a lot. Results Routines varied widely in terms of administration routes, cannabinoid content, and use timing. Overall, 18.8%, 36.2%, and 45% used non-inhalation, inhalation, and non-inhalation + inhalation routes, respectively. Those who used inhalation routes were younger (mean age 46.5 [inhalation] and 49.2 [non-inhalation + inhalation] vs. 56.3 [inhalation], F=36.1, p<0.001), while a higher proportion of those who used non-inhalation routes were female (72.5% non-inhalation vs. 48.3% inhalation and 65.3% non-inhalation + inhalation, X2=59.6, p<0.001). THC-rich products were typically used at night, while CBD-rich products were more often used during the day. While all participants reported similarly decreased pain, participants using non-inhalation + inhalation administration routes reported larger improvements in health than the non-inhalation (mean difference = 0.32, 95% CI: 0.07–0.37, p<0.001) and inhalation subgroups (mean difference = 0.22, 95% CI: 0.07–0.37, p=0.001). Similarly, the non-inhalation + inhalation group had significantly more medication substitutions than those using non-inhalation (mean difference = 0.62, 95% CI: 0.33–0.90, p<0.001) and inhalation administration routes (mean difference = 0.45, 95% CI: 0.22–0.69, p<0.001), respectively. Conclusions Subgrouping medical cannabis patients based on administration route profile may provide useful categories for future studies examining the risks and benefits of medical cannabis.

Case report: Medical cannabis—warfarin drug-drug interaction

Aim A case of an 85-year-old patient with concurrent use of warfarin and medical cannabis containing delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) is described. Warfarin continues to be a cornerstone of anticoagulation treatment despite the recent addition of FDA-approved anticoagulant agents. It is well known that warfarin has numerous drug interactions; however, much remains unknown about its interaction with THC and CBD. A literature review was conducted to identify documented cases of possible interactions between cannabis and warfarin. The case reports we identified noted that cannabis may potentially increase warfarin’s effect. Therefore, we aimed to determine why an effect was not seen on our patient’s warfarin dose despite daily use of medical cannabis. Case This case report describes an 85-year-old patient who despite starting an oromucosal medical cannabis regimen of THC and CBD (which provided 0.3 mg of THC and 5.3 mg CBD once daily and an additional 0.625 mg of THC and 0.625 mg CBD once daily as needed) had minimal INR fluctuations from October 2018 to September 2019. Conclusion Despite the introduction and use of medical cannabis therapy, with both THC and CBD components, an elderly patient with concurrent warfarin use did not see major INR fluctuations, in contrast to published literature. The potential for warfarin and THC/CBD interactions may be dependent on route of administration and dose of the cannabis product.

Impact of Harvest Time and Pruning Technique on Total CBD Concentration and Yield of Medicinal Cannabis

The definition of optimum harvest and pruning interventions are important factors varying inflorescence yield and cannabinoid composition. This study investigated the impact of (i) harvest time (HT) and (ii) pruning techniques (PT) on plant biomass accumulation, CBD and CBDA-concentrations and total CBD yield of a chemotype III medical cannabis genotype under indoor cultivation. The experiment consisted of four HTs between 5 and 11 weeks of flowering and three PTs-apical cut (T); removal of side shoots (L) and control (C), not pruned plants. Results showed that inflorescence dry weight increased continuously, while the total CBD concentration did not differ significantly over time. For the studied genotype, optimum harvest time defined by highest total CBD yield was found at 9 weeks of flowering. Total CBD-concentration of inflorescences in different fractions of the plant’s height was significantly higher in the top (9.9%) in comparison with mid (8.2%) and low (7.7%) fractions. The T plants produced significantly higher dry weight of inflorescences and leaves than L and C. Total CBD yield of inflorescences for PTs were significantly different among pruned groups, but do not differ from the control group. However, a trend for higher yields was observed (T > C > L).

UK Medical Cannabis Registry palliative care patients cohort: initial experience and outcomes

Introduction Palliative care aims to improve quality of life through optimal symptom control and pain management. Cannabis-based medicinal products (CBMPs) have a proven role in the treatment of chemotherapy-induced nausea and vomiting. However, there is a paucity of high-quality evidence with regards to the optimal therapeutic regimen, safety, and effectiveness of CBMPs in palliative care, as existing clinical trials are limited by methodological heterogeneity. The aim of this study is to summarise the outcomes of the initial subgroup of patients from the UK Medical Cannabis Registry who were prescribed CBMPs for a primary indication of palliative care, cancer pain and chemotherapy-induced nausea and vomiting, including effects on health-related quality of life and clinical safety. Methods A case series from the UK Medical Cannabis Registry of patients, who were receiving CBMPs for the indication of palliative care was undertaken. The primary outcome consisted of changes in patient-reported outcome measures including EQ-5D-5L, General Anxiety Disorder-7 (GAD-7), Single-Item Sleep Quality Scale (SQS), Pain Visual Analog Scale (VAS) and the Australia-Modified Karnofsky Performance Scale at 1 and 3 months compared to baseline. Secondary outcomes included the incidence and characteristics of adverse events. Statistical significance was defined by p-value< 0.050. Results Sixteen patients were included in the analysis, with a mean age of 63.25 years. Patients were predominantly prescribed CBMPs for cancer-related palliative care (n = 15, 94%). The median initial CBD and THC daily doses were 32.0 mg (Range: 20.0–384.0 mg) and 1.3 mg (Range: 1.0–16.0 mg) respectively. Improvements in patient reported health outcomes were observed according to SQS, EQ-5D-5L mobility, pain and discomfort, and anxiety and depression subdomains, EQ-5D-5L index, EQ-VAS and Pain VAS validated scales at both 1-month and 3-months, however, the changes were not statistically significant. Three adverse events (18.75%) were reported, all of which were either mild or moderate in severity. Conclusion This small study provides an exploratory analysis of the role of CBMPs in palliative care in the first cohort of patients since CBMPs legalisation in the UK. CBMPs were tolerated with few adverse events, all of which were mild or moderate and resolved spontaneously. Further long-term safety and efficacy studies involving larger cohorts are needed to establish CBMPs role in palliative care, including comparisons with standard treatments.