November 10-15

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ACR Convergence 2023

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Home // Despite the availability and growing popularity of medical cannabis, more clinical evidence is needed

Despite the availability and growing popularity of medical cannabis, more clinical evidence is needed


3 minutes

Mary-Ann Fitzcharles, MD
Mary-Ann Fitzcharles, MD

You’ve probably noticed CBD products and CBD-specific stores popping up almost exponentially, but there’s still so much unknown about cannabis’ effects and potential.

“In today’s reality, patients are experimenting with its use,” said Mary-Ann Fitzcharles, MD, a rheumatologist and pain medicine specialist at McGill University in Montreal, Canada, during the Tuesday session Cannabinoids: The Science for Pain Therapy. “They are accessing cannabis, often by recreational use. Unfortunately, cannabis is being promoted by storefronts, and the big question is … ‘Is the cart before the horse?’” … But medical cannabis is here to stay. There’s a public perception that it’s absolutely safe, and from the medical community, we must move ahead and advocate for good science.”

With CBD and other products widely available, patients are turning to cannabis for a variety of uses, especially chronic pain, and report having positive effects from the use. But the clinical evidence available is a “mish-mash of studies,” using different products, different durations, different doses, and other variables, said Dr. Fitzcharles. Less than 200 patients have been studied in randomized controlled trials for patients with rheumatological conditions, she noted. Seventy-one patients were studied with fibromyalgia. The only product that has been studied is Nabilone (completely synthetic THC), and a Cochrane Review indicated there was no convincing unbiased evidence at this time.

Preclinical evidence for cannabinoids is compelling, showing it has an excellent effect on acute and chronic pain and inflammation, Dr. Fitzcharles noted, and despite the lack of clinical evidence, cannabis has been used for nearly 5,000 years as medicine and is considered one of the 50 traditional herbs in Chinese medicine.

David P. Finn, PhD, Professor of Pharmacology & Therapeutics Co-Director, Centre for Pain Research, National University of Ireland, Galway, reviewed the basic science around cannabinoids and pain.

David Finn, PhD
David Finn, PhD

There is a mixture of psychomimetic and depressant effects when taking cannabis, including a feeling of relaxation and well-being and increased appetite (the munchies). But Dr. Finn said that cannabis can impair short-term memory, motor coordination, and cause dry mouth, red eyes, in addition to paranoia, anxiety, and panic attacks.

Dr. Fitzcharles and her team published a physician statement on the use of medical cannabis. Those points included avoiding cannabis during pregnancy because it can potentially cause lower birth weight and preterm birth; not using cannabis under the age of 25 because minds are still developing at that age; caution for people who have had cardiovascular events; caution for people working settings requiring concentration, executive function, and alertness; and caution in elderly patients.

“Very often, I have patients coming into the clinic with grandchildren telling them, ‘Grandma, you need cannabis for your osteoarthritis in your knees,’” she said, explaining that most of the studies done are on younger patients, and the risks must be compounded in elderly patients. Those risks include cognitive impairment, cardiovascular events, and stability.

It is also a good idea to avoid cannabis while driving because you are more likely to weave in and out of lanes, and reaction times are impaired.

Dr. Fitzgerald said physicians need to educate patients about therapeutic dosing, thinking about it in grams per day. Many of the CBD products patients are buying, often a 30 ML bottle, on the market aren’t regulated, aren’t consistent, and are potentially contaminated.

“We really don’t want our patients to say, ‘A few drops of this, and a few puffs of that,’” she said.