Cannabis and pain management

This Cannabis Education series episode will focus on the intersection of cannabis use and pain, reviewing the scientific literature. Additionally, this episode will highlight the adverse events and challenges to the utilization of cannabis for pain.

Speakers

• Samer Narouze, MD, PhD, chairman, Center for Pain Medicine at Western Reserve Hospital
• Ali J. Zarrabi, MD, internist and palliative medicine physician
• Jesse Ehrenfeld, MD, immediate past president, American Medical Association
• Michael Suk, MD, JD, MPH, MBA, professor and chair, Musculoskeletal Institute and the Department of Orthopedic Surgery, Geisinger Health System; chair, AMA Board of Trustees

Listen to the episode on the go on Apple Podcasts, Spotify or anywhere podcasts are available.

Dr. Ehrenfeld: Welcome to Moving Medicine, a podcast by the American Medical Association. Today’s episode is part of the Cannabis Education series, brought to you by the AMA Cannabis Task Force. 

I'm Dr. Jesse Ehrenfeld, senior associate dean, tenured professor of anesthesiology, and director of the Advancing a Healthier Wisconsin Endowment at the Medical College of Wisconsin. I'm also the immediate past president of the AMA and co-chair of the AMA Cannabis Task Force. Michael, take it away!

Dr. Suk: Thanks, Jesse. I'm Dr. Michael Suk, professor and chair of the Musculoskeletal Institute and the Department of Orthopedic Surgery at Geisinger Health System. I'm chair of the AMA Board of Trustees and your co-chair of the AMA Cannabis Task Force.

Through expert discussions and insights, this podcast series features information that can help physicians of all specialties understand cannabis and the health effects of cannabis use.

Dr. Ehrenfeld: The AMA forms mission-specific task forces like this one to tackle current medical issues in our nation. Make your voice heard by becoming a member today. Visit ama-assn.org/more. And now, on to the show.

Joining me today to talk about cannabis and pain is Dr. Samer Naruse, board member of the American Society of Regional Anesthesia and Pain Medicine, founder of the American Interventional Headache Society and chairman of the Center for Pain Medicine at Western Reserve Hospital. I also have Dr. Ali John Zarabi, member of the American Academy of Hospice and Palliative Medicine and an assistant professor in the Department of Family and Preventive Medicine at Emory University. Thank you both so much for joining me.

Dr. Narouze: Thank you for having me.

Dr. Zarrabi: Thank you for having us.

Dr. Ehrenfeld: So there seems to be growing interest related to cannabis products for pain. Can I start with Dr. Naruse, what can you tell us about the evidence for cannabis in the treatment of pain?

Dr. Narouze: This is a very good question. Let me start by saying that chronic pain is really very common. It affects millions of people in our country. It leads to significant disability, impaired function. So, every pain patient has the right to access effective and safe pain medications to improve function and limit disability.

That being said, there are many options for those patients with chronic pain. There are conserved treatments, non-pharmacological options, physical therapy, chiropractors. There is multiple groups of pharmacological medications, non-opioids and opioids in severe cases. So, there is a whole spectrum of options available for those patients suffering with chronic pain. When it comes to cannabis, cannabinoids, unfortunately, the evidence is not really strong yet.

We might have more evidence in the coming years, I'm expecting this. But so far, although we have really good basic science about the physiological effects of the molecules, the impact of the plant on the body, however, this did not translate to clinical research or good quality clinical research yet. We're still lacking significant advances in the clinical research.

So, for now, I would say in general, yes, it could be an option for chronic pain patients if they failed other conserved treatment or traditional options. Every patient is different. Every patient has a different story. The treatment should be really individualized, tailored to the patient's needs and expectations and outcomes.

Dr. Ehrenfeld: And am I correct in thinking that, you know, the research is still evolving, we don't have the highest quality studies, but the effect sizes are small and that there hasn't been a clear panacea for the use of these medications in treatment of pain. Is that a fair statement?

Dr. Narouze: You are correct. Because it's still scheduled as a class one. It's not FDA-approved yet. It's only approved in most of the states for medicinal use and other indications. So, because of this schedule one status, there had been shortage of good quality randomized control trials to give us the answer that we're looking for.

Most of the data that we have are from anecdotal reports, registries, cohort of patients. There are some RCT trials, but really low quality, low patient number involved, risk of bias. We don't know exactly what the patient was on during those trials because they take the cannabis plants, they are smoking it, there's different in the smoking patterns. You know, for example, you can have a smoke and you can have a deep inhalation. You can increase the dose by doing this behavior while smoking. So, we really cannot tell for sure how much the patient was on.

So, pooling all this data into like what we call meta-analysis or systematic review is not really right. We are not comparing the actual dose of molecule from one study to the other study. That's why we always call there is a high risk of bias. But in general, there are promising indicators for the potential use of some cannabis products in specific situations.

Dr. Ehrenfeld: Very helpful. Dr. Zarabi, could you expand more on the intersection of specifically cancer pain and cannabis use, which we seem to hear a lot about these days?

Dr. Zarrabi: Absolutely. So, depending on the epidemiological study, about a fifth to a fourth of cancer patients use cannabis products. And what I wish to speak about is the evidence for cannabis use in cancer and seriously ill populations, as well as approaches to harm reduction for patients who choose, really regardless of a medical recommendation, to use cannabis products to manage the symptoms and stress of their serious illness or whatever psychosocial challenges that they wish to medicate. 

So as a physician, my role is to advocate for my patient's quality of life, which includes mitigating actual or potential harms. And I've cared for thousands of patients now in my palliative care practice over the past several years who use cannabis products. And most tell me that cannabis products have helped them with their symptoms, particularly neuropathy, insomnia and appetite.

And this cohort includes some who have also told me that it's helped them more than any traditional pharmaceutical. And at the same time, I've seen patients be harmed by cannabis use. I've had patients fall. I can provide one anecdote of a patient who was using high dose cannabis suppositories ostensibly to cure her cancer and was unable to receive chemotherapy because she became too frail, and nobody knew the reason was because of the cannabis suppositories. And when they were stopped, she was able to resume treatment.

I've seen people develop delirium, lethargy, somnolence that prevents them from meaningfully interacting with the world. And for these reasons, I think it's incumbent upon us to protect our patients by meeting them where they are regarding their use of cannabis while also closely monitoring them for potential harms. And while I generally don't review evidence-based guidelines directly with my patients, I think it's important for us clinicians to be aware of where they stand.

And for example, the Multinational Association of Supportive Care in Cancer recently issued guidelines based on a systematic review of randomized control trials and systematic reviews in cancer populations. And they recommended against the use of cannabinoids for cancer-related pain as there's little evidence to support cannabinoids as an effective adjuvant or analgesic to cancer pain.

Furthermore, a Cochrane review from 2023 reviewed 14 double-blind randomized control trials involving plant-derived THC products and synthetic THC products and found that they were ineffective in relieving moderate to severe opioid refractory cancer pain. And Dr. Ehrenfeld, just one last point, acknowledging this, when my patients come in and tell me that products with THC have improved, let's say, a constellation of symptoms and reduced the number of pharmaceuticals that they take, or it's reduced generally their pill burden. You know, I won't tell them, “Well, you're wrong. The evidence doesn't support how you feel.” And that would rupture our therapeutic relationship. And similar to what Dr. Narouze alluded to, I think there's still quite a bit of research needed to explore the impact of cannabis on pain functioning, catastrophizing, ruminating in quality of life. What the evidence helps me with as a clinician is providing me with an orientation that really like any medicine, that cannabis may also cause harm. And that's something that we need to watch out for.

Dr. Ehrenfeld: Dr. Zarrabi, thank you so much. Really helpful perspectives and obviously cultivating, supporting that physician-patient relationship is so critical in making sure that we can have honest conversations with our patients about how these products are or are not being used is really, really important. So, Dr. Narouze, as we think about patient-centered approaches in this area, what concerns do you have around adverse events related to cannabis use for pain?

Dr. Narouze: Yes, cannabis is not yet a mainstream pain medicine. Definitely pediatrics, young adolescents, are high risk for adverse events for THC because of the potential negative effect on brain development. So, in general, we do not recommend it for younger than 18-years-old, better 25-years-old. And also, pregnant ladies because of the potential effect on the newborn.

And additionally, most of the clinical trials showed that there are significant side effects associated with the use of cannabis. And usually, it depends on how do you use it, how frequent, how much. So, if you're smoking or vaping a lot, you might have chronic cough, CPD issues. In general, cannabis leads to impaired senses, impaired sense of time, impaired memory, lack of coordination, impaired movement, and depending on the dose, with high doses you can get into hallucinations, delirium or even frank psychosis. 

With heavy users, long-term users, almost everyday users, they might run into what we call cannabis withdrawal symptoms with the discontinuation of the product. This usually manifests as lack of sleep, insomnia, sweating, irritability, they can shiver, stomach upset. Although they are not as strong as withdrawal symptoms from other substances, but we should educate our patient about the possibility of this, and physicians as well should be aware of this.

Dr. Ehrenfeld: I think that's an important point worth reiterating that there is, I think, pretty clear consensus across most medical specialties that cannabis ought to be avoided in those who are pregnant, particularly because of the risk to a developing fetus. You know, we hear all of these risks and it's hard because we don't have a full picture of what's happening because of the limitations around the evidence regarding cannabis and its effects. 

But if I come back to you, Dr. Zarrabi. You made earlier comments about engaging with patients, right? And helping them help us understand what's happening. Tell us how you achieve that therapeutic alliance in your practice and if there are any populations where you specifically see some opportunities around cannabis and pain use.

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Dr. Zarrabi: Sure, so in my clinical practice, oftentimes patients will come in having already tried a cannabis product, or they've never tried one, but they've read or heard something about it. And for both groups, I generally ask, what have you heard that makes you interested in trying it? Often, I hear that they wish to use it for pain.

And among my cancer patients, many wish to try it with the hope that it could treat or cure their cancer, though there is absolutely no evidence for that. Among my patients who've tried a cannabinoid, I asked them, what did it do for them? How did it make you feel? I asked them where they obtained it, and then oftentimes there's hesitancy and then I remind them that I'm not law enforcement. I'm a physician and that's why I want to know where they obtained it. And usually, it's from family and friends or from a dispensary. I asked them what kind of formulation is it? Is it a vape? Is it an oil? Is it a gummy or an edible? If patients are using oral regimens, I asked them the dose that they're taking. I think this is really important for patients coming into any really clinical practice when they're telling a clinician that they're using cannabis. I actually asked them if they're using something from a dispensary to bring it in.

I actually never touch the product or hold it in my hand because I don't want to be in possession of a schedule one drug. So, I have the patients actually show me the labeling. Oftentimes these bottles will have a concentration, particularly milligrams in a bottle from which you can calculate the actual concentration of a liquid or any oral agent. So, if a patient is taking say five drops of a THC oil, you can actually approximate the milligram content that they're using.

And then you ask, how often are you using it? How may it be helping? Is there anything that it might not be helping with or causing problems with? When we queried our own patients in our practice and published this, about one in five patients reported that they had withdrawal symptoms, or they worried about having withdrawal symptoms if they were to stop their use.

Sometimes I offer patients a urine drug screen so we can know their cannabinoid, particularly if it's not purchased from a dispensary, is laced with anything, and my patients are quite open to this. I ask caregivers, friends, family members to weigh in on my patient's cannabis use. What do they think cannabis is doing for them? And some anecdotes are, I've had patients say that cannabis is wonderful, and it makes them feel great. However, a caregiver will say that they haven't really been engaging with anyone in the family, they're sitting at home feeling high all day and dozing off. I've had other patients living with chronic pain tell me that they're not sure cannabis is doing really anything, whereas their spouse will say that their mood is much better, or they appear to be coping better with their pain. And I find data from caregivers to be very useful. 

Just a couple more things. I review common adverse events or side effects with patients, including drowsiness, dry mouth, fatigue, dizziness, anxiety, nausea. I make patients aware of this. However, I don't really lead with this. My perspective is unless someone is using any substance that has a high risk of, or a very high risk of harm, I try to optimize the placebo effect without emphasizing the nocebo. So, for example, if a patient is intent on using a cannabinoid for pain, I often express hope that it will help them while tempering it with a focus on safer use. Store your cannabis in a safe place, away from children and pets. Don't drive on cannabis or use heavy machinery for at least six hours after use. I don't lead with, well, the cannabis is likely to harm you because that may compromise my relationship with the patient and would also compromise my ability to adjudicate if the patient is actually being harmed by cannabis.

Dr. Ehrenfeld: Dr. Narouze, Dr. Zarrabi, thanks again for sharing your knowledge of cannabis use and pain. Could I just ask each of you to summarize some key points you'd like our audience and listeners to leave with, and I'll start with Dr. Naruse and then turn it over to Dr. Zarabi.

Dr. Narouze: I would like to summarize by saying that cannabis for sure is not a first-line treatment for chronic pain. For now, we should all agree to try as much as possible to avoid recommending these products for teenagers and pregnant women and patients with significant mental illnesses until we have more data to support this. Thanks.

Dr. Zarrabi: And my summary is the majority of states now have cannabis available to its citizens in the form of medical or adult use. Our patients are or will use cannabis products with or without our recommendation. And given the near ubiquity of cannabis products out there and the frequent use of cannabinoids to treat health related issues, we as clinicians need to think about cannabis like any other pharmaceutical. We need to know the onset of action, duration and drug interactions.

We need to know about general dosing and psychotropic effects that, for example, a patient can come in with one milligram of THC compared to 10, and we should expect to know what that would do for the patient. We need to study it seriously.

Like all substances, they can cause both harm and good, depending on context. And we, as physicians, when considering how to approach any medicine, need to take into account the patient sitting in front of us and the context in which they would use it. And cannabis is no different.

Dr. Ehrenfeld: Dr. Zarabi, Dr. Narouze, thank you so much for being a part of this important session on cannabis use and pain. It's a part of our cannabis educational series brought to you by the AMA Cannabis Taskforce. Again, I'm Jesse Ehrenfeld, immediate-past-president of the AMA and co-chair of the AMA Cannabis Task Force. I hope our listeners will join us for another episode in our Cannabis Education series. Thank you.

Dr. Ehrenfeld: Don’t miss the next episode in this series—be sure to subscribe to Moving Medicine on your favorite podcast platform. This content is for educational and informational purposes only and does not constitute medical or legal advice. The viewpoints expressed in this podcast are those of the participants and do not reflect the views and policies of the AMA, unless otherwise indicated. 

Dr. Suk: And this has been Moving Medicine. Thanks for listening.

Disclaimer: The viewpoints expressed in this podcast are those of the participants and/or do not necessarily reflect the views and policies of the AMA.