Cannabis-Based Medication Not the Fix for MS

Multiple sclerosis progression not slowed by dronabinol

(RxWiki News) Some multiple sclerosis (MS) patients use a cannabis-based medication called dronabinol to control pain symptoms and muscles cramps. A recent study looked at whether this medication could also stop the progression of a certain type of of MS. 

MS is a disease of the nervous system. Most patients experience symptom flare-ups, followed by periods when they feel better. For these patients, therapies are available to relieve the flare-ups

For other patients, MS symptoms continually get worse. But for these progressive MS patients, no medication is available to keep the disease from worsening.

A new study tested whether the cannabis-based medication, dronabinol, could slow MS from getting worse. This study did not find dronabinol to be effective in slowing MS progression, but did provide information on how quickly nerves weaken.

The researchers are hopeful that longer dronabinol studies could benefit MS patients.

"Talk to your doctor about controlling your MS symptoms."

John Zajicek, PhD, MBBS, MRCP, FRCP, a researcher from Plymouth University, and colleagues conducted this study to see if oral dronabinol would slow the progression of MS.

The research took place in the United Kingdom at 27 different neurology or rehabilitation centers.

The researchers had 498 participants with progressive MS between the ages of 18 to 65 years of age. There were 329 participants randomly assigned to take dronabinol and 164 participants were assigned to take a placebo (fake medication). Five participants left the study prior to treatment.

Dronabinol (brand name Marinol) is an oral medication derived from cannabis, a plant commonly known as marijuana. It is normally used to treat nausea and vomiting caused by chemotherapy. It is also used to improve appetite in patients with AIDS (acquired immunodeficiency syndrome). Some patients have effectively used dronabinol to control MS symptoms such as muscle cramping.

Dronabinol costs approximately $2-3 per pill.

Participants were given either dronabinol in a gelatin capsule or a placebo for 36 months. Neither the researchers nor the participants knew which capsule each participant was receiving.

The study measured disability caused by the progressive MS using the expanded disability status scale (EDSS), a scale from 0 to 10 which measures disability caused by MS. Participants were assessed every six months by a physician. 

Patients also reported on their everyday MS symptoms. 

The researchers made adjustments for age, type of disease, sex and weight to make certain these factors did not influence the results of the study.

Of the dronabinol patients, 145 had an EDSS score progression, meaning they continued to become more disabled by MS. In the placebo group, 73 patients had a similar EDSS score progression. In both groups, the change was smaller than the researchers expected.

The study did not show that dronabinol prevented or slowed MS from getting worse. A few of the people with less disability seemed to benefit, however. 

Both groups experienced adverse events, or negative health events. A total of 35 percent of dronabinol users and 28 percent of placebo users had an adverse event. The authors stated that the negative health events were normal MS incidents and known side effects from the cannabis product. The authors did not have any safety concerns from the study.

"In this study, the researchers were studying the hypothesis that cannabinoids may have a protective action," said Steve Leuck, PharmD, President and Owner of AudibleRx. "The methods and findings of the study appear to have been performed with appropriate controls. However, the results of the 36 months long study showed no slowing of the disease procress.

"On the bright side," said Leuck, "the researchers learned some important information about how fast (or slow) nerves degenerate, and this information may be used in follow-up studies."

The researchers indicated that the MS worsened overall more slowly than they had expected, which may have affected their ability to see whether the disease worsened in the placebo group more than the dronabinol group.

The authors also noted that more people receiving dronabinol dropped out of the study due to side effects, which made it harder to tell if the medication helped prevent the worsening of symptoms.

The authors of this study wrote that additional research is needed and this study will be helpful for future studies. They noted that, in future studies, researchers should try to recruit patients with the greatest chance of disease worsening.

This study was published on July 12 in The Lancet Neurology.

The research was funded by the UK Medical Research Council, the National Institute for Health Research Efficacy and Mechanism Evaluation programme. The researchers also received funding from the Multiple Sclerosis Society and the Multiple Sclerosis Trust. The authors reported no conflicts of interest.

Review Date: 
August 7, 2013