Expand your consciousness around medical cannabis (aka marijuana) with expert Dr Donald Abrams, Chief of the Hematology-Oncology Division at San Francisco General Hospital and a Professor of Clinical Medicine at the University of California San Francisco. We explain the cannabinoid system, THC, CBD aka cannabidiol, limitations surrounding cannabis research, current and future medical uses for medical cannabis (marijuana), and potential conditions it may benefit. We take a deep dive on the potential harms of medical cannabis and how to counsel patients on safe use. Plus, the return past guest and new correspondent, Dr Molly Heublein, Assistant Professor of Medicine from UCSF. Thanks to Dr Heublein for writing and producing this episode and it’s show notes!
Clinical case from Kashlak Memorial: MM is a 62 yo woman with a history of osteoarthritis and breast cancer, now on an aromatase inhibitor. She struggles with aching and stiffness in her hands, shoulders, knees, and hips. A friend suggested she try medical marijuana. She wants her provider’s opinion on if this is safe and effective.
Cannabis and Marijuana are both terms for the whole plant/flower. Dr Abrams prefers the term cannabis due to stigma around marijuana, but we will use the terms interchangeably here. Tetrahydrocannabinol (THC) and Cannabidiol (CBD) are the best studied cannabinoids (active components of cannabis), but there are an estimated 140 biologically active components in the marijuana plant. CBD is less psychoactive than THC since this compound does not bind to cannabinoid receptors in the brain. Cannabis is available as herbal cannabis products (e.g. “weed”, oils, edibles), or as synthetic cannabinoids like dronabinol (synthetic delta-9 THC).
The pharmacodynamics of cannabis differ by route of ingestion. Orally, cannabis has low and variable bioavailability with a peak plasma concentration in ~2.5 hours, and a half-life of 20-30 hours. Delta-9 THC undergoes 1st pass metabolism through the liver and is converted to an even more psychoactive 11-hydroxy metabolite. When inhaled cannabis achieves peak plasma concentration within 2.5 minutes, dissipates rapidly over 30 minutes, and has less psychoactive effects since it largely avoids 1st pass metabolism by the liver. The body has it’s own endocannabinoid system with many of the effects from THC and CBD occurring via agonism or antagonism at cannabinoid receptors, CB1 and CB2. Fun fact: CB1 is the most densely populated receptor in the brain and responsible for many of the mood, motor, and cognitive effects of cannabis!
Cannabis cannot be prescribed without a schedule one license, but in California, cannabis can be “recommended” for specific indications by physicians. A letter of support is written and the patient brings this to the dispensary. At the dispensary, the “budtender” can recommend specific strains or preparations based on patient’s situation. Patients discover the most effective product by trial and error. In California, marijuana dispensaries offer a wide range of products: under the tongue sprays, tinctures, topical salves, suppositories, and snacks…even potato chips! There is no data about the bioavailability/metabolism of these products. The reported THC/CBD ratio reported by dispensary products is often incorrect.
Please note that in some states, only CBD is legal. Check your local laws here for specifics of how it works in your area.
Marijuana’s classification as a schedule one drug limits its ability to be studied as it is listed as a drug of abuse with no medical benefit. NIDA (National Institute on Drug Abuse) primarily funds research into the harms of cannabis, rather than benefits, so the literature around its uses is limited.
Goal: Listeners will have a greater knowledge of medical marijuana and the evidence behind its use for various medical conditions.
After listening to this episode listeners will…
Disclosures: Dr Abrams reports acting as a Scientific Advisor to ABcann, AXIM Biotechnologies, Inc, Maui Wellness Group, Scriptyx, and Tikun Olam.
01:30 Picks of the week
03:40 Guest bio
05:11 Getting to know our guest
11:03 Clinical case
11:40 Limitations for cannabis research
12:59 Discussion of THC and cannabidiol
14:50 Smoking versus ingesting cannabis products
16:40 Recap of cannabinoid mechanism of action
18:30 Cannabis and cannabinoid products available
20:20 Synthetic THC (dronabinol)
21:46 How “recommending” cannabis and dispensaries work
25:46 Conditions that respond to medical cannabis
29:15 Potential harms of medical cannabis
34:51 Future directions of cannabinoid medicine research
37:24 Cannabis induced hyperemesis syndrome
39:00 Possible lung cancer risk
40:12 Take home points
42:54 The Curbsiders recap and share their views on the medical cannabis controversy
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