Medicine & Research

Medical Marijuana in MS

By Ellen Whipple, Pharm.D.
Though marijuana has existed for hundreds of years, research into its clinical properties and potential medicinal uses has only begun to take shape in the last 20 years. Several recent studies have investigated the potential use for medical marijuana in spasticity and pain associated with multiple sclerosis. Many people with MS are unable to find consistent relief from these symptoms using traditional medications and cannabis may be an option for those who live in states where it has been legalized for medicinal purposes. A 2017 survey of individuals with MS found that 47 percent of respondents had considered using medical marijuana to alleviate MS symptoms.

What is medical marijuana?

“Medical marijuana” is another name for medical cannabis. At the federal level in the U.S., the DEA classifies cannabis as a Schedule I substance, which means that there are no currently accepted medical uses, a lack of robust safety data, and a high potential for abuse. However as of July 2019, 33 states and the District of Columbia have passed legislation legalizing the use of marijuana for medicinal purposes. Officials in these states cannot officially “prescribe” cannabis because of its Schedule I status, but they can write a recommendation for its use in certain conditions. Each state’s procedures are slightly different, but most require a physician recommendation, thorough documentation of a qualifying medical condition, and a registration with the state to obtain a medical marijuana card.

Cannabis itself is made up of several different components. One of the groups of chemical compounds in cannabis is known as cannabinoids, which bind to cannabinoid receptors in the body and change the way neurotransmitters release in the brain. CBD, or cannabidiol, is the major nonpsychotropic cannabinoid in marijuana, and is usually found in concentrations of less than 1 percent in the naturally grown plant. THC, or tetra-hydrocannabinol, is the most psychoactive component of cannabis, and can be found in concentrations anywhere from 1 to 24 percent. Most cannabis-derived medications being developed now are synthetic THC compounds, though several do include CBD.

In December 2018, federal law was slightly altered to remove “hemp” from the definition of cannabis which is classified as a Schedule I product. Hemp is considered to be any cannabis- containing plant or substance that is less than 0.3 percent THC. This new bill determined that these products would no longer be considered a controlled substance. Most widely available CBD oils are hemp products, which is what allows them to sell in the majority of states. To date, no clinical evidence has shown benefit of using CBD oils for MS symptoms

Side Effects/Safety

As with any medication, there are certain side effects associated with the use of medical marijuana. Some of the most common side effects include mental confusion, dizziness, sedation, increased appetite, and dry mouth or eyes. Other side effects may include vomiting, anxiety, impaired balance and coordination, headaches, or elevated heart rate. Side effects may vary depending on the dosage and route of administration. Since most medical marijuana research is extremely recent, the long-term safety of cannabis products is largely unknown. Use of medical marijuana could interact with other prescription or non-prescription medications, and the use of any cannabis-containing products should always be discussed with a physician.

Use in MS

There are currently no generally accepted guidelines or FDA approved cannabis medications for use in MS, but there have been several evidence-based reports of medical cannabis that included outcomes for MS symptoms, focusing on spasticity and pain. Spasticity is one of the most common symptoms of MS, and is defined by a sudden stiffening of muscles, causing heaviness, involuntary movements, or temporary immobility. Evidence has not shown benefit in treating bladder-related symptoms or tremor in MS patients.

In 2014, the American Academy of Neurology published a guideline for use of complementary and alternative medicine options, which included the conclusion that oral cannabis extract and synthetic THC compounds are probably effective for reducing patient-reported symptoms of spasticity and pain in MS. More recently, a 2017 review of the therapeutic cannabis uses by the National Academies of Sciences, Engineering, and Medicine determined that there was significant evidence supporting the efficacy of cannabis treatment for improving MS spasticity symptoms.

In the U.S., there are three FDA-approved cannabis-related drug products and one cannabis- derived product, none of which have an approved indication for use in MS. Epidiolex is the most recently approved medication, and is a purified CBD substance used for seizures. The other three approved medications include dronabinol or nabilone, synthetic THC compounds, and are used for improving appetite in people with AIDS and for chemo-therapy-induced nausea and vomiting. The complex legal status of cannabis in the U.S. has significantly limited its use in clinical trials.

Though not currently approved for use in the U.S., Sativex (nabiximols) is a combination of THC and CBD medication that is manufactured in the form of a mouth spray. Sativex is approved in Canada, New Zealand, and a variety of European countries for treatment of spasticity caused by MS. There are currently several large ongoing studies at sites in Europe into the potential efficacy of dronabinol for MS spasticity not controlled by first-line treatment options.