Master the ins-and-outs of medical cannabis! Dr. Julia Arnsten (@DrArnsten) will lead us through the initial evaluation of a patient interested in medical cannabis, summarize the state of evidence for the benefits and harms, lay out a schema for dosing and formulations, provide pearls on how to counsel patients, and more!
Claim free CME for this episode at curbsiders.vcuhealth.org!
Episodes | Subscribe | Spotify | Swag! | Top Picks | Mailing List | firstname.lastname@example.org | Free CME!
The Curbsiders are partnering with VCU Health Continuing Education to offer FREE continuing education credits for physicians and other healthcare professionals. Visit curbsiders.vcuhealth.org and search for this episode to claim credit. See info sheet for further directions. Note: A free VCU Health CloudCME account is required in order to seek credit.
Visit grammarly.com/CURB and get 20% off when you upgrade to Grammarly Premium.
Visit medmastery.com/curbsiders to claim a 15% lifetime discount on and of their subscriptions.
Visit Locumstory.com to learn more about locums
Go to GreenChef.com/curb130 and use code curb130 to get $130 off, plus free shipping
Cannabis is currently approved for medical use in 37 states (NCSL, 2022) Dr. Arnsten describes medical cannabis as a “pharmaceutical that can help people with specific symptoms using specific doses of the active ingredients in the cannabis plant.”
Terminology: “Marijuana” vs “cannabis”: The term “cannabis” refers to the cannabis plant, which contains various chemical substances, including THC, CBD, and other cannabinoids and terpenes (National Academies of Sciences, Engineering, and Medicine, 2017). The term “marijuana” is a “cultural rather than scientific term” with a particular history in the United States, linked to racism and xenophobia, according to Dr. Arnsten. Dr. Arnsten notes that the appropriate term to use is “cannabis” rather than “marijuana.”
Terminology: “Recreational use” vs “non-medical use“ or “adult use” – Dr. Arnsten prefers the terms “non-medical use” or “adult use” rather than “recreational use.” She stresses that over half of individuals who are purchasing cannabis in a dispensary without a medical card are buying it to treat a particular symptom like pain or insomnia.
In the United States, early use of cannabis in the medical setting was in the form of tinctures, which were widely prescribed by doctors during the 19th and early 20th centuries for a range of symptoms, including cough, pain, menstrual cramps, and neuralgia. Then, during Prohibition and the Great Depression, alcohol and cannabis were prohibited, and the government began an effort to “free society” from cannabis, according to Dr. Arnsten. The government attempted to link cannabis to immigrants from Mexico, and in this context the term “marijuana” was coined to associate cannabis with Mexican immigrants. Later in the twentieth century, the era of Nixon and the War on Drugs had a profound effect on the history of medical cannabis, ultimately resulting in wildly disproportionate rates of incarceration for cannabis offenses for people of color.
When taking the history of a patient interested in certification for medical cannabis, Dr. Arnsten notes that the following items are critical:
There are now tens of thousands articles on PubMed exploring the conditions in which medical cannabis may be useful. Five years ago, a panel from the National Academy of Science, Engineering, and Medicine convened to review this literature and develop a set of guidelines on medical cannabis use (National Academies of Sciences, Engineering, and Medicine, 2017.) The guideline panel identified three conditions for which the evidence is sufficient to consider recommending medical cannabis:
There are many other conditions for which patients can be certified for medical cannabis use that do not have as robust an evidence base as these three, and Dr. Arnsten notes that for many disease states the “use of cannabis and enthusiasm is ahead of the evidence.” She points out that the lists of conditions for which patients can be certified to receive medical cannabis are usually generated by politicians, not doctors, and vary from state to state.
The efficacy of cannabis for anxiety is less clear than for chronic pain (National Academies of Sciences, Engineering, and Medicine, 2017). Dr. Arnsten notes that the situation can be particularly complicated when a patient is using cannabis for both chronic pain and anxiety, as it can be difficult to tease out what they are medicating and how the cannabis is helping them. As the literature on cannabis use for anxiety develops further, Dr. Arnsten said that she suspects that THC will likely worsen anxiety in high doses but may be effective at low doses, while she suspects that CBD will likely be effective for anxiety.
Dr. Arnsten stresses that the major barrier to rigorously analyzing the potential therapeutic benefits of cannabis is the current status of cannabis as a Schedule 1 substance (Ross et al, 2022). This fact means that conducting medical research on cannabis is extraordinarily difficult and demands “lots of perseverance.” Dr. Arnsten notes that cannabis for research must be acquired through the federal government (and there are questions about whether this cannabis is actually the same as cannabis acquired from proprietary companies), and that getting research studies on cannabis off the ground often requires 4-5 years of paperwork. As a result of these barriers to research, answers to important questions about the therapeutic efficacy of cannabis are not available.
According to Dr. Arnsten, CBD has few side effects of which we are aware. High doses of CBD (for instance, doses used for severe seizure disorders) have been linked to liver enzyme abnormalities (Ewing et al, 2019; Samanta, 2019). However, doses of CBD used by most patients are generally benign.
THC, on the other hand, has several important adverse effects:
When determining the appropriate starting dosage of medical cannabis for a patient who is already using cannabis, Dr. Arnsten will start with a thorough history of how often the person buys cannabis and how much they usually purchase (Ross et al, 2022). One ounce (1 oz) of cannabis is equal to 28,000 mg total cannabinoids. Most street cannabis is estimated to be about 10% THC. Thus, if a person is using 1 oz of cannabis per month, this means they are using 28,000 mg total cannabinoids (or 2,800 mg THC per month), which is equivalent to 930 mg total cannabinoids daily (or 93 mg THC daily) (Ross et al, 2022).
For patients currently using cannabis, Dr. Arnsten recommends a therapeutic dose of medical cannabis equal to 50% or less of what they are currently taking (so for someone using 1 oz of cannabis per month, this would be 40-50 mg of THC, taken in 10-20 mg doses every 4-8 hours) (Ross et al, 2022). She will initially start a lower dose for the first 2-3 days of medical cannabis use, and then incrementally increase until the therapeutic dose is reached.
Different formulations of cannabis are available with different proportions of THC:CBD: in New York, the formulations are 1:1 THC:CBD or 20:1 THC:CBD (formulations can vary state-to-state). Dr. Arnsten recommends that the cannabis formulation be tailored to the individual based on their cannabis use at time of assessment: if they have no or minimal cannabis use, a 1:1 THC:CBD formulation of medical cannabis should be used, while if they use cannabis more heavily, a 20:1 THC:CBD formulation of medical cannabis would be preferred initially to help treat their pain (with a plan to transition eventually to a 1:1 formulation) (Ross et al, 2022). In patients with heavier baseline cannabis use, Dr. Arnsten says that a harm reduction approach should be adopted, with the aim to get patients on a lower dose that helps them but doesn’t put them at risk.
In titrating medical cannabis dosage, Dr. Arnsen encourages patients to keep a diary of how much medical cannabis they take and how they feel each time. Then, over the next 4-6 weeks, she works to find a dose that works best for them.
Dr. Arnsten encourages use of tinctures or edibles (including pills, gel caps, or gummies), and discourages smoking or baked goods. During her conversations with patients, she provides counseling on why smoking cannabis is harmful, explaining how cannabis rolled in joints with tobacco or wrapped in tobacco paper can expose patients to the risks of tobacco. Additionally, even if tobacco is not involved, long-term cannabis smoking can have harmful pulmonary effects, including respiratory symptoms and more frequent chronic bronchitis episodes (Tetrault et al, 2007; National Academies of Sciences, Engineering, and Medicine, 2017).
If patients are smoking cannabis at baseline, Dr. Arnsten will explain to them that the goal is to stop smoking cannabis and move entirely to the medical product. She acknowledges that this may not happen immediately, though she tells her patients that they should abstain from smoking cannabis for at least 24 hours prior to starting the medical product, so that they can understand the effect of the medical product.
For those who are accustomed to smoking cannabis and are transitioning to tinctures or edibles, Dr. Arnsten will explain to them that they should expect a different experience. The effect timing is one notable difference; while patients will usually feel an effect from smoking in about 5 minutes, tinctures and edibles usually take between 60 and 90 minutes to take effect. She recommends that patients take edibles a couple of hours before they go to bed, so they have time to see how it is affecting them.
Dr. Arnsten emphasizes that there are notable disparities in access to medical cannabis. To undergo the certification process, an individual needs to have Internet access, access to a healthcare provider, and to pay a fee for the evaluation / certification process (Ross et al, 2022). At Montefiore, Dr. Arnsten has developed an embedded program within primary care so patients don’t need to pay for the evaluation process (Ross et al, 2022). However, they still are required to pay for the product when they get to the dispensary, which many can’t afford (Ross et al, 2022): Dr. Arnsten notes that only about half of the people that her program certifies end up going to the dispensary and purchasing the product. In order to save money, many patients also space out their medical cannabis supply over a longer period of time, and often don’t end up getting up to a therapeutic dose and thus may not experience full therapeutic efficacy. Additionally, Dr. Arnsten notes that this cumbersome system has spawned the growth of many predatory programs such as online and telephone certifiers that take advantage of people. She stresses that pushing for more equity in access to medical cannabis is critical.
In the medical community, there is interest in whether medical cannabis can reduce use of opioids. Results from ecological studies investigating whether prescription of opioids is lower in states that have legalized medical cannabis have been conflicting. However, Dr. Arnsten notes that these studies have not addressed the real question, which is: for a given patient, does starting medical cannabis lead to use of less opioids? This question has yet to be answered, and is the subject of an ongoing research study at Montefiore (Cunningham et al, 2020.)
Listeners will receive updates on the current state of medical cannabis and recognize potential benefits and harms.
After listening to this episode listeners will be able to…
Dr. Arnsten reports no relevant financial disclosures. The Curbsiders report no relevant financial disclosures.
Watto MF, Arnsten J, Gandhi MM, Williams PN. “#335 LIVE! Medical Cannabis: Is it still dope?”. The Curbsiders Internal Medicine Podcast. http://thecurbsiders.com/episode-list. May 30, 2022.
The Curbsiders are partnering with VCU Health Continuing Education to offer FREE continuing education credits for physicians and other healthcare professionals. Visit curbsiders.vcuhealth.org and search for this episode to claim credit.
Got feedback? Suggest a Curbsiders topic. Recommend a guest. Tell us what you think.
We love hearing from you.
Yes, you can now join our exclusive community of core faculty at Kashlak Memorial Hospital along with all the perks:
Close this notice to consent.
Excellent podcast, wished it would extend for another hour! I practice outpatient psychiatry and addiction medicine in a tribal location. Our state has just approved legalization of cannabis, and we are awaiting decisions within the tribe regarding how this will affect our providers and patients. This is truly a broad topic! I will share this with peers to help open more productive discussions about how we can safely and effectively incorporate medical cannabis into the excellent program we are currently engaged in. One immediate question: You said there would be a link to patient evaluation forms that are being utilized at Montefiore, though I haven't found one. Can this be made available? and please bring back Dr Arnsten for more! Thanks for what you guys do!
Just emailed you :)
Hello! Thank you for a wonderful podcast! I am having a hard time accessing the NEJM catalyst article. Any help you can provide would be appreciated.
Hi! We just emailed you :)
Hi Matthew. I (finally) had a chance to listen to this podcast. As you know, concussion management is evolving rapidly. There are now specific treatments (mostly physical therapy) for problems with vision and balance, neck pain, etc. The physical exam for vestibular-opthalmologic can help determine what types of treatment should be offered.
Great info! Thanks for listening Richard!