Medical Marijuana (Medical Cannabis)

  • Medical Author:
    Erica Oberg, ND, MPH

    Dr. Erica Oberg, ND, MPH, received a BA in anthropology from the University of Colorado, her doctorate of naturopathic medicine (ND) from Bastyr University, and a masters of public health (MPH) in health services research from the University of Washington. She completed her residency at the Bastyr Center for Natural Health in ambulatory primary care and fellowship training at the Health Promotion Research Center at the University of Washington.

  • Medical Editor: John P. Cunha, DO, FACOEP
    John P. Cunha, DO, FACOEP

    John P. Cunha, DO, FACOEP

    John P. Cunha, DO, is a U.S. board-certified Emergency Medicine Physician. Dr. Cunha's educational background includes a BS in Biology from Rutgers, the State University of New Jersey, and a DO from the Kansas City University of Medicine and Biosciences in Kansas City, MO. He completed residency training in Emergency Medicine at Newark Beth Israel Medical Center in Newark, New Jersey.

Medical marijuana facts

  • Medical marijuana is a plant-based medicine from the Cannabis sativa or Cannabis indica species with three major active compounds: THC, CBD, and CBN.
  • Medical marijuana is used for
  • The health benefits of medical marijuana include relief from pain and muscle spasm, nausea associated with chemotherapy, and anorexia.
  • Benefits are seen in immune function, neuroplasticity, emotional and mood regulation, vascular health and digestive function. Research is limited but studies of the endocannabinoid system suggest benefits may include neuroprotection (in MS, epilepsy, other movement disorders), and benefit in a number of mood and anxiety disorders.
  • The side effects of medical marijuana are minimal when used at low doses and include dry mouth and fatigue. At higher doses, side effects include dizziness, paranoia, and psychoactive effects.

Medical Marijuana Types and Uses For Treatment

Medical marijuana or medical cannabis refers to any part of the marijuana plant that is used to treat health problems. Medical marijuana is not used to get "high." Some of the uses for medical marijuana are

  • to control pain,
  • to ease nausea,
  • to treat loss of appetite,
  • to treat some symptoms of multiple sclerosis, and...

What is medical marijuana or medical cannabis?

Medical marijuana is the medical use of the Cannabis sativa or Cannabis indica plant to relieve symptoms of, or treat diseases and conditions. The Cannabis plant was used medically for centuries around the world until the early 1900s. Medical marijuana facts can be difficult to find because strong opinions exist, both pros and cons. Medical uses and emerging research on off-label uses are summarized in this article.

What are THC and CBD?

THC or tetrahydrocannabinolis the psychoactive compound in marijuana. It is responsible for the "high" people feel. There are two man-made drugs called dronabinol (Marinol) and nabilone (Cesamet) that are synthetic forms of THC. They are FDA-approved to prevent nausea and vomiting in people receiving chemotherapy.

CBD or cannabidiol is another compound in marijuana that is not psychoactive. CBD is thought to be responsible for the majority of the medical benefits.

Epidiolex is a CBD oil extract that is undergoing clinical trials for epilepsy.

THC:CBD: Nabiximols (Sativex) is a specific plant extract with an equal ratio of THC:CBD. It is approved as a drug in the UK and elsewhere in Europe for the treatment of multiple sclerosis, spasticity, neuropathic pain, overactive bladder and other indications.

Medical marijuana products are available with a huge range of THC and CBD concentrations. Expert opinion states that 10mg of THC should be considered "one serving" and a person new to medical marijuana should inhale or consume no more until they know their individual response.

What are the uses for medical marijuana?

Medical uses of marijuana include both studied and approved uses and off-label uses. In a recent research survey, the most common reasons people use medical marijuana are for

  • pain,
  • anxiety,
  • depression,
  • muscle spasticity, and
  • inflammatory bowel diseases such as Crohn's disease.

More research has been conducted on the compound CBD. Medical CBD is anti-inflammatory, anticonvulsant, antioxidant, neuroprotective, and anxiolytic, antipsychotic, and anti-emetic. The CBD compound in medical marijuana appears to be neuroprotective in Huntington's, Parkinson's, and Alzheimer's disease, fetal hypoxia, and other neurodegenerative conditions and movement disorders.

What are the health benefits of medical marijuana?

There are over 60 peer-reviewed research studies examining the benefits of medical marijuana. Sixty-eight percent of these studies found benefit while 8% found no benefit. Twenty-three percent of the studies were inconclusive or neutral. Most research has been conducted on the compound CBD. The benefits of medical marijuana can be attributed to binding to the endocannabinoid system. This has many effects including

  • modulating the immune system,
  • promoting neuroplasticity,
  • emotional and cognitive modulation including learning and motivation, appetite, vascular function, and digestive function.

Are there any side effects of medical marijuana?

Medical marijuana side effects are minimal when used at low doses and include

At higher doses, side effects include

There are concerns about adverse effects of cannabis among adolescents because the risks are greater to the immature brain and neurological system. Concerns include increased risk of schizophrenia and loss of IQ.

There are public health concerns about the safety of driving under the influence of medical marijuana. A JAMA study found lower rates of opioid overdose deaths in states with legal medical marijuana.

Is medical marijuana legal?

At the time this article was written, 23 states have legalized medical marijuana with varying restrictions. However, it is classified as a Schedule I substance by the Federal Drug Administration (FDA), and thus is illegal at the Federal level. In most states with legal medicinal marijuana, a prescription, authorization, or medical recommendation is required, and a card or license is issued. This allows a person to buy medical marijuana.

How do you get medical marijuana?

In states where medical marijuana is legal, shops, often called dispensaries, sell marijuana products in a variety of forms. Medical marijuana is available in edible forms (candies or cookies), oils and extracts, and as the plant which can be smoked or otherwise inhaled. Dispensaries require a medical marijuana card before they will sell products. How people can get a medical marijuana card varies by state. It requires a prescription from a licensed health-care professional.

Is medical marijuana "addictive?"

Most research suggests a very low risk of addiction and very low toxicity of medical marijuana when taken as recommended in low therapeutic doses. There is concern about psychological dependence in heavy users and whether this constitutes marijuana abuse. Some research has suggested CBD oil might be useful in treatment for marijuana addiction or marijuana abuse.

What research is being done for medical marijuana?

There are numerous studies underway on medical marijuana, but research is challenged by limited access given the FDA classification. A search of the National Institutes of Health funded projects list in 2016 revealed 165 studies related to cannabis and 327 studies related to the search term marijuana. The majority of these studies are surveys into use patterns. Many are also basic science studies investigating how the endocannabinoid system in the brain and immune system works. Survey studies that anonymously assess users habits and reported benefits may provide insight into the effects of real-world use patterns. There are over 60 peer-reviewed research studies that have been published about medicinal cannabis. Sixty-eight percent of these studies found benefit while 8% found no benefit. Twenty-three percent of the studies were inconclusive or neutral. The most promising areas of research appear to be in the use of CBD for neuroprotection.

REFERENCES:

Teesson, M. et al. "The relationships between substance use and mental health problems: evidence from longitudinal studies." In: Stockwell, T. et al. "Preventing harmful substance use: the evidence base for policy and practice." Chichester, UK: John Wiley; 2005. p. 43-51.

Fernández-Ruiz, J. et al. "Cannabidiol for neurodegenerative disorders: important new clinical applications for this phytocannabinoid." Br J Clin Pharmacol. 2013 Feb;75(2):323-33.

Sexton, M., et al. "A Cross-Sectional Survey of Medical Cannabis Users: Patterns of Use and Perceived Efficacy." (Under Review 2016: Cannabis and Cannabinoid Research).

Murnion, B. "Medical Cannabis." Aust Prescr. 2015 Dec; 38(6): 212–215.
<http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4674028/>

Bachhuber, MA., et al. "Medical cannabis laws and opioid analgesic overdose mortality in the United States." 1999-2010. JAMA Intern Med. 2014 Oct;174(10):1668-73. Erratum in: JAMA Intern Med. 2014 Nov;174(11):1875.

Allsop, DJ., et al. "Nabiximols as an agonist replacement therapy during cannabis withdrawal: a randomized clinical trial." JAMA Psychiatry 2014;71:281-91.

Brunt, TM., et al. "Therapeutic satisfaction and subjective effects of different strains of pharmaceutical-grade cannabis." J Clin Psychopharmacol. 2014 Jun;34(3):344-9.

Last Editorial Review: 3/28/2016

Reviewed on 3/28/2016
References
REFERENCES:

Teesson, M. et al. "The relationships between substance use and mental health problems: evidence from longitudinal studies." In: Stockwell, T. et al. "Preventing harmful substance use: the evidence base for policy and practice." Chichester, UK: John Wiley; 2005. p. 43-51.

Fernández-Ruiz, J. et al. "Cannabidiol for neurodegenerative disorders: important new clinical applications for this phytocannabinoid." Br J Clin Pharmacol. 2013 Feb;75(2):323-33.

Sexton, M., et al. "A Cross-Sectional Survey of Medical Cannabis Users: Patterns of Use and Perceived Efficacy." (Under Review 2016: Cannabis and Cannabinoid Research).

Murnion, B. "Medical Cannabis." Aust Prescr. 2015 Dec; 38(6): 212–215.
<http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4674028/>

Bachhuber, MA., et al. "Medical cannabis laws and opioid analgesic overdose mortality in the United States." 1999-2010. JAMA Intern Med. 2014 Oct;174(10):1668-73. Erratum in: JAMA Intern Med. 2014 Nov;174(11):1875.

Allsop, DJ., et al. "Nabiximols as an agonist replacement therapy during cannabis withdrawal: a randomized clinical trial." JAMA Psychiatry 2014;71:281-91.

Brunt, TM., et al. "Therapeutic satisfaction and subjective effects of different strains of pharmaceutical-grade cannabis." J Clin Psychopharmacol. 2014 Jun;34(3):344-9.

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