Ethos Ho, BSc Pharm Student
Hashing Out the Evidence in Multiple Sclerosis
Today’s article is a continuation of our series examining the current evidence behind medical marijuana in the management of various medical conditions. So far, we have discussed its use in chronic pain, cancer, and ADHD. The focus of today’s article is the safety and effectiveness of medical cannabis in the treatment of pain and spasticity associated with multiple sclerosis. Commonly known as MS, multiple sclerosis is a chronic neurological disorder characterized by the destruction of various structures in the central nervous system.1
A widely accepted theory is that multiple sclerosis is caused by an autoimmune attack on parts of the central nervous system, such as the myelin and axons.1 These components are essential for the normal functioning of neurons, which play a crucial role in the transmission of electrical nerve signals throughout the central nervous system. This degeneration manifests as a vast array of symptoms which can include: numbness, spasticity, weakness, fatigue, cognitive difficulties, bowel/bladder abnormalities, and neuropathic pain.1
Spasticity and Pain Associated with Multiple Sclerosis3-5
Of the vast symptoms that are encountered with MS, muscle spasticity occurs in up to 75% of patients. Spasticity refers to feelings of stiffness and involuntary muscle spasms (sustained muscle contractions or sudden movements). The severity of muscle spasticity can range from mild (feelings of the tightness of muscles) to severe (painful and uncontrollable spasms of the extremities). Spasticity can occur around the joints and can also cause lower back pain. As well, spasticity can occur in any limb; however, it’s much more common in the legs. The most common medications that are used in the treatment of spasticity are muscle relaxants (ex. baclofen and tizanidine), diazepam, and botulinum toxin.
Another common and disabling symptom of MS is pain, which is present in up to 86% of patients. Most of the pain patients experience is either central neuropathic pain, or pain from spasms. As mentioned previously in the article about cannabis use in chronic pain, it’s believed that THC (the therapeutic component of medical cannabis) works to relieve pain by acting on cannabinoid receptors in the brain.
What Does the Evidence Say?2-5
There is some high-quality evidence that supports the use of medical cannabis in the management of MS-related spasticity and pain. In Canada, there is only one marijuana product on the market with consistent, reliable evidence of safety; an oromucosal spray containing marijuana extract called Sativex®. One quality study found that Sativex® was clinically beneficial and produced better results in resistant MS-related spasticities when used as add-on therapy compared to adjusting first-line anti-spasticity medications alone (ex. baclofen and tizanidine).
Similar findings were found in the management of pain. A study in 2011, which pooled the effects of cannabinoids of any type (smoked, oral extracts, nabilone (Cesamet®), synthetic THC, Sativex®) on chronic non-cancer pain (including but not limited to pain from MS), found that 15 out of the 18 studies found at least modest pain relief with cannabinoids.
Treatment with medical cannabis was generally well-tolerated, with common side effects being drowsiness, dizziness/lightheadedness, diarrhea, vomiting, and nausea. Take a look at the chronic pain article for more information about safety considerations!
The Bottom Line
MS is a chronic neurological disorder characterized by the destruction of structures in the central nervous system. Common and potentially debilitating symptoms of MS include muscle spasticity and pain. There is evidence suggesting that medical cannabis is an effective therapeutic option in the management of these symptoms and may be used along with conventional therapy to optimize results. Medical cannabis is generally well-tolerated with some common minor side effects, such as lightheadedness/dizziness and drowsiness. Although there have been high-quality studies that suggest a benefit with medical cannabis, it’s important that you consult with your healthcare provider before initiating treatment. This is especially important once recreational marijuana becomes legal and other formulations become available for use!
As always, we hope you took away something valuable from this piece. If you have any questions or concerns regarding this article or others, feel free to reach out to us on Instagram, Facebook, or at ask@orbishealth.ca with your feedback. We’d love to hear from you.
RESOURCES
- Rxtx
- Markovà, J., Essner, U., Akmaz, B., Marinelli, M., Trompke, C., Lentschat, A., & Vila, C. (2018). Sativex® as add-on therapy vs. further optimized first-line ANTispastics (SAVANT) in resistant multiple sclerosis spasticity: a double-blind, placebo-controlled randomised clinical trial. International Journal Of Neuroscience, 1-10. doi: 10.1080/00207454.2018.1481066
- van Amerongen, G., Kanhai, K., Baakman, A., Heuberger, J., Klaassen, E., & Beumer, T. et al. (2017). Effects on Spasticity and Neuropathic Pain of an Oral Formulation of Δ9-Tetrahydrocannabinol in Patients WithProgressive Multiple Sclerosis. Clinical Therapeutics. doi: 10.1016/j.clinthera.2017.01.016
- Rice, J., & Cameron, M. (2018). Cannabinoids for Treatment of MS Symptoms: State of the Evidence. Current Neurology And Neuroscience Reports, 18(8). doi: 10.1007/s11910-018-0859-x
- Nielsen, S., Germanos, R., Weier, M., Pollard, J., Degenhardt, L., & Hall, W. et al. (2018). The Use of Cannabis and Cannabinoids in Treating Symptoms of Multiple Sclerosis: a Systematic Review of Reviews. Current Neurology And Neuroscience Reports, 18(2). doi: 10.1007/s11910-018-0814-x
