Marijuana for Medical Purposes Could Help Patients With MS, But Uncertainty Remains

Drugs containing the major chemical compounds of cannabis are associated with a limited and slight reduction in muscle contractions, bladder dysfunction and pain, based on self-reports of patients in clinical trials included in a prescription. new evidence analysis.

"In the end, there is definitely something going on with cannabinoids regarding symptoms," said Nicholas LaRocca, vice president of health care and policy research at National Multiple Sclerosis. Society.

However, patients themselves report benefits related to muscle contractions differing from the results of objective scales used by doctors, noted LaRocca. Doctors have not seen any such benefits with marijuana drugs.

"It's something that is obviously a concern," LaRocca said.

Clinical trials have also shown that cannabis-derived drugs have few side effects and no serious effects, said Dr. Marissa Slaven, Assistant Professor of Palliative Care at McMaster University in Hamilton, Ontario, Canada.

"This definitely adds to the literature by suggesting that it is safe treatment," said Slaven, who wrote an editorial accompanying the new evidence review. "Whether it's effective or not, I think we need more research."

The examination of evidence, conducted by Mari Carmen Torres-Moreno, of the University of Barcelona in Spain and her colleagues, included clinical trials involving four preparations derived from cannabis: Oral cannabis extract, Nasal cannabis extract and drugs Dronabinol and Nabilone.

Dronabinol and nabilone are both synthetic versions of THC, the chemical found in marijuana that causes intoxication. Both are used to treat nausea and vomiting caused by chemotherapy.

The new evidence review combined 17 clinical trials involving 3,161 patients. The researchers concluded from the review that cannabis-derived drugs can be considered safe and have limited effectiveness in treating the symptoms of MS.

Side effects associated with medications included dizziness, dry mouth, fatigue, intoxication, balance problems, memory problems and drowsiness. But this did not result in a statistically significant number of people who withdrew from the trials.

"There was a very slightly positive effect that was perceived as a positive statistic, but it's hard to tell if it's a clinical result," Slaven said.

The result of the review is that further research is needed to determine the ability of marijuana for medical purposes to help people with multiple sclerosis, agreed LaRocca and Slaven. Multiple sclerosis is a degenerative and progressive disease in which the immune system attacks the nerves, producing various neurological symptoms.

"Despite a very keen interest in cannabinoid therapy, we have relatively little good research to help us determine what works and what does not work, what works for what types of cannabinoids." individuals, etc. ", LaRocca. I said.

Because of the lack of evidence, practitioners tend to recommend other established treatments for MS than drugs derived from marijuana, he added.

"There is actually relatively little solid data, I think it discourages practitioners from feeling comfortable with recommending this because there is simply not as much data available," explained LaRocca.

Marijuana research for medical purposes has been hampered in the United States because of restrictions based on federal law, LaRocca said.

It was hoped that producers and processors of marijuana could fund medical research to better establish the effectiveness of their products, but the wave of legalization of recreational use could have hindered this, said Slaven.

"I'm afraid that with the legalization of marijuana for recreational purposes, companies are making a lot of money in this way and have no incentive to invest in medical research," she said.

Slaven added that none of these tests involved smoked marijuana. Instead, they focused on cannabis extracts and synthetic versions of THC. The cannabis extracts also included cannabidiol, a chemical compound found in marijuana that is not intoxicant but may have some medical benefits.

"We know that there are so many cannabis-based products, but we do not know which components are the most important and most effective at the moment," Slaven said.

The new evidence analysis was published online on October 12 in JAMA Network open now.

Explore further:
Q & A: Treatment with medical cannabis

More information:
JAMA Network open nowonline. jamanetwork.com/journals/jaman… andworkopen.2018.3485

The National Multiple Sclerosis Society has more about marijuana for medical purposes and MS.