Rheumatologists ‘must acknowledge the real-world need’ to understand medical cannabis use
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Despite a lack of “gold standard” evidence surrounding cannabis use for musculoskeletal pain, rheumatologists must not turn a blind eye to how such products are used by their patients in the real world, according to researchers.
“Most evidence for the medical use of cannabinoids in rheumatic diseases has been accrued from patient surveys, cohort studies and a handful of randomized controlled trials, often using the few pharmaceutical products available, and often at doses that have not been titrated to effect,” Mary-Ann Fitzcharles, MB, ChB, of the department of rheumatology and the Alan Edwards Pain Management Unit at McGill University, in Montreal, told Healio. “Therefore, the gold standard of high-quality evidence is not currently available.”
“However, even in the absence of ideal studies, physicians must acknowledge the real-world need to understand medical cannabis use, especially as somewhere between 15% to 30% of our patients are either currently using or have tried medical cannabis,” she added. “As the astronomer Carl Sagan once said, ‘Absence of evidence is not evidence of absence.’”
To better understand these real-world issues, and offer advice to rheumatologists about talking to patients about medical cannabis, Fitzcharles, alongside Hance Clarke, MD, of the pain research unit and the transitional pain service at Toronto General Hospital and the University of Toronto, and colleagues conducted a review of the current evidence as it pertain to musculoskeletal pain.
According to their findings, which they published in Current Rheumatology Reports, data show that although some patients report improvements in pain and associated symptoms, there are adverse effects to be considered. In addition, there is significant uncertainty among both patients and providers about the nature of available evidence and the use of medical cannabis in the rheumatology setting.
However, despite these concerns, Clarke and Fitzcharles stated they are encouraged by ongoing research that may provide more clarity on medical cannabis use. Ongoing communication between patients, providers and the wider research community is necessary to ensure safe and optimal use of these products, they said.
Healio sat down with Clarke and Fitzcharles to discuss the rationale for their review, the pitfalls in interpreting the currently available evidence and pointers for rheumatologists who need to talk to their patients about cannabinoid use.
Healio: Why did you decide to study medical cannabinoids in rheumatology in the first place? What were you hoping to achieve?
Fitzcharles: My colleagues and I, in the rheumatology and pain medicine community, have been impressed by the number of people with rheumatic diseases either trying cannabis on their own or requesting information on the use of cannabis for certain symptoms — mostly pain, but also sleep disturbance.
Pain management today for many rheumatic conditions is suboptimal. This is particularly noticeable for those with fibromyalgia and osteoarthritis of the lower limbs, where we know that persistent pain is only partially improved with current recommended strategies. Nonpharmacologic treatments that include multidisciplinary approaches, exercise, good lifestyle practices and selective drug treatments are often not sufficiently effective for many patients.
Clarke: In this climate of prevalent use or interest among our patients, it is the responsibility of the medical community to understand the effects of cannabinoids, using the best evidence available to competently counsel patients in a spirit of shared decision making without bias. As Canada has a history of medical cannabis access dating back to 2018, Canadian physicians have become more comfortable with this dialogue and have experience with the patient-reported effects, but also acknowledge the need for a true scientific understanding of cannabis’ effects.
In view of the restrictions and difficulties in conducting the usual randomized trials needed for drug approval, we have accumulated the current knowledge regarding cannabis use by means of patient surveys as a next best method of understanding cannabis’ role in rheumatology care.
Healio: Why is there so little evidence on cannabinoids in rheumatology?
Clarke: Traditional evidence-based study, via randomized clinical trials, has been hindered for a number of reasons. These include the illegal status of cannabis in many countries, regulations governing the exact product — down to the exact chemical composition required by regulatory authorities — available for studies, and the diversity that is intrinsic to a plant product that contains hundreds of molecules.
In addition, there was in the past a stigma associated with cannabis in light of its use as an illegal recreational product. This stigma discouraged many patients from using cannabis, divulging its use or even participating in survey studies. This stigma is now much less prevalent, which has allowed for more interest in study participation among patients.
Fitzcharles: Challenges still persist, as many patients have already tried cannabis on their own, formulated their own opinion and may therefore be less willing to participate in formal study.
Healio: What are some of the trials that are now under way that you believe may change the landscape? What diseases or conditions are they studying?
Clarke: Most clinical trials currently underway are focused on the two conditions that often present the greatest challenges in pain management — fibromyalgia and lower limb osteoarthritis.
According to information on ClinicalTrials.gov, we are encouraged to note that almost all studies are assessing oral or topical preparations of cannabis. Inhalation is generally not recommended for many health reasons. However, it is notable that the patient-preferred method of administration in the United States is inhalation.
We will be particularly interested to see the results of products containing mostly cannabidiol (CBD), which has less psychoactive effects than THC, and also eagerly await results of topical preparations. Meanwhile, topical agents are greatly attractive to older persons who are often already on various oral preparations for associated comorbidities.
Healio: What clarity do you hope will come from the current research?
Fitzcharles: There are three big questions. Does cannabis work to reduce symptoms? If it works, what is the best preparation? And will prolonged use result in long-term side effects that are not at this time evident for medical use?
Healio: What side effects come with cannabinoid use for musculoskeletal pain, and how should rheumatologists be addressing these incidents?
Clarke: Patients are very attuned to the adverse effects of medications, and this is likely the reason that approximately one-third to a half of patients trying medical cannabis discontinue use.
The most prevalent immediate side effect is “just not feeling right,” being a little dizzy, a little floaty and just not in full control of psychomotor functions. Many patients therefore only use cannabis at night, especially when they do not intend to drive. Additional troublesome side effects include dry mouth, somnolence, fatigue and nausea. Occasionally, some patients may report increased anxiety.
Fitzcharles: Side effects such as dizziness or poor balance have potential to increase the risk for falls or other accidents, and should be noted particularly in the elderly or in those using other psychotropic medications, or substances such as alcohol. A much rarer side effect — if taken in high quantities — that rheumatologists should also keep in mind is cannabis-induced hyperemesis syndrome. Emesis can also occur with abrupt cessation in individuals consuming high amounts of THC.
Healio: You mentioned that many rheumatology patients are already using cannabinoids to manage pain, fatigue, help with sleep, etc. How should rheumatologists be talking with these patients about these products?
Clarke: Medical cannabis should be treated as any other medication used by a patient. There should be medical-record documentation of the product being used — including concentration of CBD and THC — the amount being used, timing of use, and both the efficacy and side effects. Inhalation should be strongly discouraged. Products that have the “flavor” of not being for truly medical use, such as a cannabis-laced cookie or gummies, should also be discouraged, as this type of administration detracts from the notion of a therapeutic product.
Fitzcharles: A trial of medical cannabis should be critically evaluated, as for any other medication, and if deemed not sufficiently effective, or with unacceptable side effects that outweigh efficacy, the product should be discontinued. Clinical care should remain in the domain of the physician with a full knowledge of the patient, and should not be delegated to a health care professional whose function is only to prescribe cannabis.
References:
Clarke H, et al. Curr Rheumatol Rep. 2024;doi:10.1007/s11926-024-01162-9.
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