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Medical Marijuana Is a Dangerous Lie

Mosley, Mark MD, MPH

doi: 10.1097/01.EEM.0000695644.08448.0a
    Figure
    Figure:
    marijuana

    Marijuana is not a medical drug. It is a slang term for a plant of the Cannabis family that contains more than 60 different cannabinoid substances and more than 80 biologically active compounds. Using the term marijuana in place of THC would be like using willow tree in place of acetylsalicylic acid, the active ingredient in aspirin.

    Even worse would be creating a multibillion-dollar industry using the term medical willow tree for a product that may not even contain acetylsalicylic acid. The consequences of peddling the term medical marijuana are far graver, however, than simply confusing a whole plant with one of its active ingredients.

    The most commonly discussed compounds in the Cannabis plant are tetrahydrocannabinol (THC) and cannabidiol (CBD). THC is lipid-soluble, highly bound to the brain, and interacts with endogenous cannabinoid receptors, making it psychoactive. CBD does not attach to the cannabinoid receptors in the brain, and is not psychoactive.

    Only three Cannabis-related compounds are currently made for medical purposes, none of which has much scientific support. (JAMA. 2015;313[24]:2456; https://bit.ly/30BwkA5; Can Fam Physician. 2018;64[2]:e78; https://bit.ly/3hggTTU.) Delta-9-tetrahydrocannabinol is a synthetic cannabinoid called dronabinol (trade names: Marinol and Syndros). Its only FDA-approved indications are for weight gain in patients with HIV wasting syndrome and severe intractable nausea for chemotherapy patients.

    Another THC isomer synthetically made is nabilone (trade name: Cesamet), an oral drug for severe chemotherapy nausea and spasticity for multiple sclerosis patients. Insurance does not cover them, and dronabinol costs upwards of $1000 per month and nabilone close to $2000 per month. These THC-containing compounds are the only FDA-approved drugs for rare circumstances that are predominantly end-stage (compassionate use) where the clinical science is mostly anecdotal. (JAMA. 2015;313[24]:2456; https://bit.ly/30BwkA5.)

    The third compound is an oral cannabidiol compound with no THC in it, Epidiolex. It is only 13-19 percent bioavailable when taken orally. (Front Pharmacol. 2018;9:1365; https://bit.ly/2AudArL.) The FDA approved the drug for extremely rare intractable seizures in Dravet syndrome and Lennox-Gastaut syndrome. The drug's benefits are debatable. It decreased the frequency of seizures in these devastating syndromes, but showed no overall improvement in quality of life, and was not included in the European National Institute for Health and Care Excellence recommendations. (BMJ. 2019;366:l5280.) Epidiolex is also a pharmacologically monitored CBD drug with a much higher concentration of CBD than what is sold over the counter as CBD oil.

    These three compounds are the only medical Cannabis-related products, and all are synthetically made, FDA-approved, monitored for purity, safety, and consistency, and require a prescription. They are extremely expensive. Even under these conditions, there is poor science supporting their benefit. Perhaps future science will uncover more about the brain's cannabinoid receptors that will change these negative conclusions, but it will require good clinical science instead of “I've talked with patients who used marijuana for cancer, and it really helped!” No science currently proves medical benefit. It is not just a lie but a dangerous one to suggest there is anything medical about marijuana.

    The lie of medical marijuana is a classic example of availability bias. (JAMA. 2015;313[3]:241; https://bit.ly/2UEOVHR.) Five years ago, the idea that marijuana should be legal or that it might be medically beneficial to large segments of the population would have brought widespread laughter. Even those who were medical marijuana believers would have to admit that it was really an intentional misnomer to allow the legalization of recreational marijuana without feeling guilty.

    It is now taken for granted that a large portion of high school kids are vaping weed and that grandmothers are buying CBD oil for arthritis. The more it is talked about and advertised as normal and even therapeutic, the more it is accepted as true. It is inconsistent that everyone seems to be embracing the widespread availability of marijuana when opioids and THC have similar neurobiological effects.

    The brain has a natural cannabinoid system much like the intrinsic endogenous opioid receptors. Both increase dopamine, which registers as a reward and suppresses negative emotion and suffering. Exogenous opioids and exogenous cannabinoids also increase dopamine but to a much greater extent than endogenous pathways. When stimulated chronically, dopamine becomes down-regulated. Cannabinoids, completely separate from any pain-relieving properties, which initially decreased suffering, anxiety, and negative mood make one hypersensitive to suffering, anxiety, and negative mood.

    THC is known for its acute immediate effects of slow thinking and difficulty with problem-solving, altered time and sense misperception, and memory difficulties can cause psychosis when used at higher doses. (N Engl J Med. 2014;370[23]:2219; https://bit.ly/3hmxTrM.) Marijuana used chronically is correlated with lower life satisfaction, poorer mental health, poorer relationships, decreased IQ, and low resilience. Mentally ill people in particular tend to self-medicate with marijuana, which paradoxically increases their anxiety and psychosis. It is reported that 20 percent of pregnant women under 24 use marijuana, though its effects on the fetal brain are unknown. (JAMA. 2017;318[24]:2490; https://bit.ly/3hnJoiE.)

    Other associations include COPD, increased motor vehicular collisions, Cannabis hyperemesis syndrome, childhood overdoses from edibles, a gateway to harder drugs, and decreased school and work performance. Illicitly made marijuana can be laced with K2, fentanyl, and embalming fluid. (N Engl J Med. 2014;370[23]:2219; https://bit.ly/3hmxTrM.) It is true that overdosing on marijuana is rarely life-threatening, unlike opioids, but addiction and mental illness could actually be worse than opioids due to availability.

    Now that a farm bill in December 2018 allowed hemp to be produced and marketed, many more of our farmers are growing marijuana for the billion-dollar CBD oil market, a basically worthless compound based on no science. Many people are marketing and using CBD products off-label, and some are selling and promoting them illegally in human and veterinary medicine. CBD will not contribute to addiction or mental illness, but it will continue to blur the line of what is meant by medical marijuana, and will dramatically increase demand and political will for legalizing medical and recreational marijuana, which for all pragmatic purposes become the same.

    This political and medical schizophrenia is strange. If preventing addiction and helping the mentally ill is a moral and social imperative regarding opioids, why isn't it for THC and marijuana? Medical marijuana is not an answer to chronic pain control, and any suggestion that using marijuana will help one use opioids less is an imaginary hope not based on good science.

    We are already receiving reports of the possible cardiotoxicity of marijuana with high THC content. (Trends Cardiovasc Med. 2019;29[7]:403.) The opioid crisis will be followed by the Cannabis crisis because no matter the safeguards in place for the safer distribution of marijuana in any form, people who crave the dopamine from exogenous opioids or cannabinoids will fall into the same pattern of a brain reward system gone wrong. The difference between exogenous opioids and cannabinoids is that opioids have a proven scientific role in medicine and surgery; THC and marijuana do not.

    Dr. Mosleyis an emergency physician in Wichita, KS.

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