The Use of Medical Marijuana: Update from AAN

The American Academy of Neurology took a closer look at the use of cannabinoids/marijuana and extracts of the plant for use to treat an assortment of neurological symptoms and shared its finding and recommendations at the annual conference. Medical marijuana has been proposed as treatment for many diseases of the brain and with the exception of MS, it appears none of those uses hold up for now under further study according to the AAN Summary of evidence-based guideline: Complementary and alternative medicine in multiple sclerosis. The AAN for now takes the position that medical marijuana does "not appear to be helpful in treating drug-induced (levodopa) movements in Parkinson’s disease. Not enough evidence was found to show if medical marijuana is helpful in treating motor problems in Huntington’s disease, tics in Tourette syndrome, cervical dystonia and seizures in epilepsy."
-AAN Issues Findings on Use of Medical Marijuana in Treatment of Certain Brain Diseases

However, they did find enough support in some of the studies to make recommendations for use of medical marijuana for some specific MS symptoms. For this discussion the types of marijuana and its derivatives are split into three categories: Medicinal marijuana, Pharmacological agents derived from extracts of cannabis, and Marijuana procured in a non-pharmacy dispensed manner (often referred to as street drugs).

No naturally occurring form of cannabinoids or derivatives of cannabis are approved by the FDA at this time for use in treating Multiple Sclerosis, and that is one major cause for concern expressed by the medical community at large. There have been no studies performed on the lasting efficacy of its use or the potential of long-term side effects. Marinol, a prescription drug that is a synthetic made compound resembling the active ingredients in marijuana, was not included in this study. Marinol has been approved for use in treating nausea in cancer patients since 1985 and is the only FDA approved synthetic cannabinoid drug.

Pill or spray forms of cannabinoids and not smoked marijuana, are the only type of cannabis that has been scientifically studied in a way that meets rigorous standards, and those results are promising. The two identified studies that used rigorous methods, support findings that extracts from cannabis in the form of Sativex and THC show improvement in patients for spasticity and pain from spasms, but did not demonstrate improvement for tremors or neuropathic pain. Sativex, manufactured in the UK by GW Pharmaceuticals, is a cannabinoid oromucosal mouth spray (similar to how an asthma inhaler works), and is approved in Europe, New Zealand and Canada for us by people with MS. It has been given fast-track approval status by the FDA for finishing the studies for its use in controlling pain in cancer patients.

Medical marijuana that is smoked has been looked at in a few studies as well, but not in a rigorous scientific manner. There is a major concern that smoking marijuana can cause problems with memory and cognitive functioning, two areas that are already a major concern for most people with MS. Smoked marijuana is difficult to study due to a number of factors, including dosage size is hard to regulate and the exact chemical composition/strength of the medical marijuana can vary widely.

Marijuana from other sources – the street drugs - is non-regulated, and poses a long list of problems in studying whether it works or not. The most obvious would be the drug is not produced in a controlled environment and would be widely varied in potency and purity. Clinicians will continue to hear anecdotal stories that smoking marijuana like this is effective, but it has not been proven and is impossible to study.

Negatives from the use of cannabinoids are also addressed in the review. The long term lung cancer risk of smoking marijuana has not been fully explored and that possibility raises more concerns. The studies show there can be an adverse psychological response to medical marijuana, and found 1 in 100 people will have increased depression and altered mood with its use. Other side effects found in more than one study include dizziness, feeling intoxicated, weakness and fatigue.

The summary report is a mixed bag of results for medical marijuana, but shows the AAN recognized this is a drug that needs to be better understood by clincians and patients. The National Multiple Sclerosis Society has updated its position on medical marijuana to include the following:

"The question of whether marijuana — produced from the flowering top of the hemp plant, Cannabis sativa — should be used for symptom management in multiple sclerosis (MS) is a complex one. It is generally agreed that better therapies are needed for distressing symptoms of MS — including pain, tremor and spasticity — that may not be sufficiently relieved by available treatments. Development of more treatments for MS symptoms is a priority for the National Society in its 2011-2015 strategic response. Still, there are uncertainties about the benefits of marijuana relative to its side effects. The fact that marijuana is an illegal drug in many states and by federal statute (see Supreme Court ruling below) further complicates the issue.

The Society supports the rights of people with MS to work with their MS health care providers to access marijuana for medical purposes in accordance with legal regulations in those states where such use has been approved. In addition, the Society supports advancing research to better understand the benefits and potential risks of marijuana and its derivatives as a treatment for MS."

With continued research and legal reform in the remaining states where medical marijuana is currently not available, the time may not be that far off when providers and patients will have medical marijuana as another option in treating symptoms of multiple sclerosis.

Wishing you well,


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