Marijuana has been used for medical purposes for thousands of years. It is derived from one of the oldest cultivated plants, Cannabis sativa, and its use spans many different cultures. The main active chemical in marijuana is delta-9-tetrahydrocannabinol (THC).
Marijuana can be used in many different forms. The simplest and most common two methods of use are smoking and ingesting the leaves or resin of the plant. The resin is known as hashish. THC is available by prescription in pill form (Marinol or dronabinol). An oral spray, known as Sativex, is available by prescription in Canada. Sativex contains both THC and cannabidiol, another component of marijuana. A synthetic form of THC (Cesamet or nabilone) is available in Europe, Australia, and Canada.
Evaluation in MS and Other Conditions
The effects of the chemical components of marijuana (cannabinoids) have been extensively investigated. Cannabinoids bind to proteins known as CB1 and CB2 receptors. Through these actions, cannabinoids may decrease pain and spacticity, and mildly suppress the immune system. Cannabinoids also have antioxidant properties and decrease a harmful biological process known as excitotoxicity. Theoretically, these effects could benefit people with MS.
Marijuana, THC, and nabilone have been researched in MS and many other diseases. In 1999, the National Academy of Sciences/Institute of Medicine (NAS/IOM) reported their analysis of the clinical and scientific data concerning the medical potential of marijuana. This report found that marijuana and THC could be useful for treating pain, alleviating chemotherapy-related nausea, and fighting off the weight loss that commonly occurs in people with cancer and AIDS. Due to the dangers associated with smoking, the report also suggested that new drug delivery methods should be developed,.
The NAS/IOM also found some positive results for the treatment of MS-associated muscle spasticity. However, many of these studies are hampered by poor methodology.
Dr. John Zajicek and his colleagues conducted the first large-scale formal clinical trial of marijuana in MS. This project, called Cannabinoids in MS (CAMS), involved more than 600 people with MS. After 13 weeks or either THC or placebo treatment, the researchers found that THC had no objective therapeutic effect on several MS symptoms. Contrary to the objective measures, people subjectively self-reported improvements in pain, spasticity, and sleep quality. After a one-year follow-up, THC appeared to have a small therapeutic effect on MS-associated spasticity. Due to the findings of CAMS, a three-year, 500-person clinical trial, known as Cannabinoid Use in Progressive Inflammatory Brain Disease or CUPID, is now being conducted in the United Kingdom.
Other smaller scale research involving marijuana and marijuana-derived chemicals in MS suggests that these compounds may improve pain, spasticity, bladder problems, sleeping issues, and mobility difficulties.
Survey research has also been conducted evaluating marijuana use in MS. Surveys are not as reliable as rigorous, objectively measured clinical trials. The results of surveys suggest that marijuana may improve symptoms such as anxiety, depression, pain and spasticity.
The effects of marijuana on the immune system are yet to be fully understood. In animal and human studies, marijuana has been found to have immune effects that have ranged from inhibition to stimulation to no effect whatsoever.
Marijuana has also been evaluated in EAE, an experimental animal form of MS. THC and other marijuana-derived compounds have been reported to reduce tremor and spasticity in mice with EAE. This research also found that high doses of these compounds decreased the overall severity of EAE. EAE is far from a perfect model of MS, and findings in EAE may not directly correlate to work in MS.
Marijuana use has many possible adverse effects. People who smoke marijuana may experience nausea, vomiting, sedation, and increase their risk of seizure. Pregnant women should avoid smoking marijuana. After smoking marijuana, a person’s ability to drive may be affected for up to eight hours. Large doses may impair coordination, heart function, vision, and reaction time. Long-term use is associated with impaired lung function, heart attacks, dependence, and apathy. Smoking marijuana may also increase the risk of developing lung, head, and neck cancer. Marijuana may also amplify the effects of both sedating and stimulating medications.
Marijuana possession, sale, and use are illegal in many states and countries, including the United States.
Marijuana has many possible benefits for people with MS, but is also associated with many possible side effects. It may help with spasticity, sleep difficulties, pain, and bladder control. Further research concerning marijuana and related substances for the treatment of MS is needed. People using marijuana to treat MS symptoms should discuss this with their physician. Although there are possible benefits to marijuana, safer, more effective prescription drugs for MS symptoms are often available. Users should be aware that marijuana use may be illegal.
References and Additional Reading
Bowling AC. Complementary and Alternative Medicine and Multiple Sclerosis. New York: Demos Medical Publishing, 2007, pp. 170-173.
Bowling AC, Stewart TS. Dietary Supplements and Multiple Sclerosis. New York: Demos Medical Publishing, 2004, pp. 50–52.
Iversen LL. The Science of Marijuana. New York: Oxford University Press, 2000.
Baker D, Pryce G, Croxford J, et al. Cannabinoids control spasticity and tremor in a multiple sclerosis model. Nature 2000;404:84–87.
Baker D, Pryce G, Giovannoni G, et al. The therapeutic potential of cannabis. Lancet Neurol 2003;2:291–298.
Bowling AC. Worthless weed or pot of gold? Int J MS Care 2004;5:138,166.
Clark AJ, Ware MA, Yazer E, et al. Patterns of cannabis use among patients with multiple sclerosis. Neurol 2004;62:2098–2100.
Fox P, Bain PG, Glickman S, et al. The effect of cannabis on tremor in patients with multiple sclerosis. Neurol 2004;62:1105–1109.
Katona S, Kaminski E, Sanders H, Zajicek J. Cannabinoid influence on cytokine profile in multiple sclerosis. Clin Exp Immunol 2005;140:580–585.
Killestein J, Hoogervorst ELJ, Reif M, et al. Immunomodulatory effects of orally administered cannabinoids in multiple sclerosis. J Neuroimmunol 2003; 137:140–143.
Vaney C, Heinzel-Gutenbrunner M, Jobin P, et al. Efficacy, safety and tolerability of an orally administered cannabis extract in the treatment of spasticity in patients withmultiple sclerosis: a randomized, double-blind, placebo-controlled, crossover study. Mult Scler 2004;10:417–424.
Wade DT, Makela P, Robson P, et al. Do cannabis-based medicinal extracts have general or specific effects on symptoms in multiple sclerosis: a double-blind, randomized, placebo-controlled study on 160 patients. Mult Scler2004;10:434–441.
Zajicek J, Fox P, Sanders H, et al. Cannabinoids for treatment of spasticity and other symptoms related to multiple sclerosis (CAMS study): multicentre randomized placebo-controlled trial. Lancet 2003;362:1517–1526.
Zajicek J, Sanders HP, Wright DE, et al. Cannabinoids in multiple sclerosis (CAMS) study: safety and efficacy data for 12 months follow up. J Neurol Neursurg Psych 2005;76:1664–1669.