In the news 05/05/21: Cannabis users don't get less exercise than non-users; cannabis as part of pediatric Ca Tx; and more
Cannabinoid research of note and findings of significance from the editors of the Canadian Journal of Medical Cannabis
How much do we know about patients who self-medicate with cannabis, independent of their physician's advice? Most doctors will reply, "Not enough."
How well do we understand the way cannabis use can interact with a patient's existing health conditions? Many practitioners are likely to repeat the previous answer.
This edition of CJMC Fortnightly summarizes recent research that looks for explanations to these questions and others.
If you're new to our e-newsletter, we're pleased to welcome you to our community. We're here every two weeks with an update on new findings about medical cannabis. I'm John Evans, senior editor of the Canadian Journal of Medical Cannabis (CJMC), a scientific publication produced in Toronto, Canada. CJMC also hosts the Real World Medicannabis symposia. Here's your report for this week.
Many young cancer patients using MC oils
One-fifth of children being treated for cancer at a single clinic were using cannabis products, primarily oils.
This finding comes from a survey of patients or caregivers of children with cancer attending a pediatric oncology clinic between Oct. 2019 and March 2020. A total of 64 respondents completed the anonymous 40 question paper survey.
Data breakdown
14 (22%) of participants used cannabis
Half the cannabis users reported that they were using it as a treatment for cancer, for symptom management, or both
The most frequent diagnosis among cannabis users was leukemia
The majority of leukemia patients were still receiving conventional cancer treatments as wellAll cannabis users reported symptom improvement
Five of the caregivers of cannabis users (36%) procured cannabis from their friends
Oil formulation was the most common form of cannabis used (86%)
Most participants received information on cannabis from another parent (29%) or a doctor (29%)
Monthly expenditures on cannabis varied widely, from less than CAD$50 to more than CAD$500
Bottom line
Cannabis use is relatively common in this pediatric cancer centre, though in many cases, the cannabis and information on it come from informal sources, and expenditures are inconsistent.
PRICING UPDATE: On April 21, 2021, medical cannabis company Cardiol Therapeutics Inc. announced a price reduction for its Cortalex 100 mg/mL THC-free CBD oral solution. The product, available in Canada through the Medical Cannabis by Shoppers program, is now priced at CDN$199 for 30 mL, half the price it was when it was introduced to the market. Cardiol is also offering an additional 40% reduction in cost for pediatric patients and their caregivers.
Risk of psychotic experience higher in cannabis users with genetic risk factors
A new study suggests that while cannabis users have higher rates of psychotic experiences than non-users, this elevated risk is more pronounced in individuals who have a high genetic predisposition to schizophrenia.
The investigators conducted a cross-sectional study of data from 109,308 participants in the U.K. Biobank. They examined how the polygenic risk of schizophrenia influenced the association between self-reported cannabis use and auditory hallucinations, visual hallucinations, persecutory delusions, and delusions of reference.
Findings
Across the cohort, there was a strong, dose-dependent relationship between cannabis use and all four types of psychotic experiences
The association was strongest with persecutory delusions
Cannabis users’ psychotic experiences tended to have an earlier onset and cause greater distress than non-users
Cannabis users’ psychotic experiences were less likely to lead to seeking help compared to non-users
Polygenic risk scores showed stronger associations between cannabis use and both kinds of hallucinations, as well as with delusions of reference and with psychotic experiences overall
Key take-aways
The findings confirm that cannabis use is a predictive risk factor for psychotic experiences and that individuals who are genetically predisposed to schizophrenia may be especially vulnerable to psychotic experiences as a result of using cannabis. They also support the potential for using polygenic risk scores to inform personalized harm reduction interventions, the authors write.
Insights from the world of medical cannabis research
Evidence-based guidelines or published research (or, in the absence of both, direct experience) is the best guide to detecting and managing unfamiliar medical conditions. Our encounter with a pediatric asthma patient who had developed a cannabis allergy provided us with just such an experience. My colleagues and I believe that this type of evidence, although anecdotal, is worth sharing. In addition to serving as a guidepost of sorts to help practitioners recognize similar cases, it offers important lessons that can be applied in clinical practice.
Dr. Nathan Rabinovitch, Denver, Colo.-based physician. (CJMC 2019; 1(3):18).
Cannabis users are not exercise-slackers
Contrary to stereotype, data show that cannabis use is not associated with decreased exercise among young and middle-aged adults.
This is the conclusion of a retrospective data review of the two most recent waves of the U.S. National Longitudinal Study of Adolescent to Adult Health (Wave IV, 2008–2009; n=14,784 and Wave V, 2016–2018; n=12,043).
Characteristics considered
Any form of exercise or sport within the past seven days
Number of days participating in each of seven specific types of exercise or sport
Current use of cannabis
Frequency of cannabis use in the prior 30 days
Findings
The investigators found no significant association between cannabis use and exercise, particularly for fixed-effects models. Contrary to much of existing literature, the investigators note, the only significant estimates they found suggest a positive relationship, even among individuals who used cannabis heavily during the past 30 days.
Insights from the world of medical cannabis researchPotentially, if cannabis were to be proven safe in clinical trials in the IBD [inflammatory bowel disease] population—and that is a big if—it could possibly be used for symptom management and therefore as an adjunct therapy with an existing drug such as [adalimumab]. But it would have to be used in conjunction with the existing medication and not replace it.
This is important because many people with Crohn’s disease self-medicate, which raises safety concerns. The IBD and Crohn’s disease population is commonly diagnosed relatively early in life, which can make MC [medical cannabis] use problematic for some people. For example, because cannabis is known to alter brain development, it is strongly contraindicated in pregnant women or in early childhood.
Keith Sharkey, PhD, professor of physiology and pharmacology and Crohn's and Colitis Canada Chair in IBD Research at the University of Calgary (CJMC 2020; 2(1):14)
Heart arrhythmia raises hospital death risk
Hospitalized cannabis users who have cardiac arrhythmia are 4.5 times as likely to die in hospital than cannabis users without the heart condition, according to a report presented at EHRA 2021, an online scientific congress of the European Society of Cardiology.
The study was conducted using the U.S. National Inpatient Sample database, which covers 97% of the U.S. population.
Study population
2,457,544 adult cannabis users admitted to hospital from 2016 to 2018
187,825 (7.6%) of included patients had an arrhythmia
Atrial fibrillation was the most common form of arrhythmia, followed by abnormally slow heart rate and abnormally fast heart rate
Arrhythmic patients had a higher average age: 50.5 years vs. 38.3 years for those without an arrhythmia
Arrhythmic patients had more co-existing health conditions
Risk findings
After adjusting for age, sex, race, income, presence of diabetes, heart failure, chronic kidney disease, obesity, and the hospital's location, the investigators found that cannabis users with arrhythmia were 4.5 times as likely to die in hospital. They had longer average hospital stays than those without arrhythmia (5.7 days vs. 5.1 days).
Bottom line
In a press release, the study’s lead author Dr. Sittinun Thangjui said: “Our study highlights that heart rhythm disorders may be a warning sign for an increased risk of death in people who use cannabis. More studies are needed to confirm our results. In the meantime, it seems sensible to screen these patients for arrhythmias if they present to hospital so that those with a heart rhythm problem can be closely monitored.” Dr. Thangjui practices at the Bassett Healthcare Network in Cooperstown, N.Y.
The next edition of CJMC Fortnightly will be distributed on Wednesday, May 19. Sign up for a free subscription by clicking the link below. Here’s your editor’s LinkedIn account. Feel free to e-mail me with suggestions and questions.
If you are a healthcare provider and you found this newsletter valuable, you may wish to request a subscription to the Canadian Journal of Medical Cannabis, our quarterly Medical Cannabis research publication, at www.cjmc.ca