FRIDAY, Dec. 4, 2009 (HealthDay News) -- Cancer patients, glaucoma patients and others can benefit from medical marijuana, and now a new analysis shows that it can help multiple sclerosis (MS) patients find relief from the muscle spasms that are the hallmark of the debilitating autoimmune disease.
"The therapeutic potential of cannabinoids in MS appears to be comprehensive, and should be given considerable attention," said lead researcher Dr. Shaheen Lakhan, executive director of the Global Neuroscience Initiative Foundation.
"Spasticity, an involuntary increase in muscle tone or rapid muscle contractions, is one of the more common and distressing symptoms of MS," the researchers noted in their review. "Medicinal treatment may reduce spasticity, but may also be ineffective, difficult to obtain or associated with intolerable side effects," they added.
"We found evidence that cannabis plant extracts may provide therapeutic benefit for MS spasticity symptoms," Lakhan said.
Although some objective measures showed improvement, there were no significant changes in after-treatment assessments, Lakhan said. "However, subjective assessment of symptom relief did often show significant improvement post-treatment," he added.
For the study, Lakhan and his colleague Marie Rowland reviewed six studies where marijuana was used by MS patients. Five of the trials showed that marijuana reduced spasms and improved mobility, according to the report published Dec. 3 in the online journal BMC Neurology.
Specifically, the studies evaluated the cannabis extracts delta9-tetrahydrocannabinol (THC) and cannabidiol (CBD). These studies found that both THC and CBD extracts may provide therapeutic benefit for MS spasticity symptoms, Lakhan said.
Although there was a benefit from using marijuana there were also side effects, such as intoxication. This varied depending on the amount of marijuana needed to effectively limit spasms, but side effects were also seen in the placebo groups, Lakhan and Rowland noted.
The careful monitoring of symptom relief and side effects is critical in reaching an individual's optimal dose, Lakhan said. "Moreover, there is evidence that cannabinoids may provide neuroprotective and anti-inflammatory benefits in MS," he added.
"Considering the distress and limitations spasticity brings to individuals with MS, it would be important to carefully weigh the potential for side effects with the potential for symptom relief, especially in view of the relief reported in subjective assessment," Lakhan said.
Dr. Moses Rodriguez, a professor of neurology and immunology at the Mayo Clinic, said that "the idea of using cannabis to treat MS has been around for a long time."
Rodriguez noted that the effects of using marijuana have been mixed. "It has been difficult to know whether the effect has been just a general well-being or whether it has a direct effect on muscle fibers and spasticity," he said.
If drugs could be developed that take away the intoxicating effects of marijuana, it could have a direct effect on spasms without the high, Rodriguez said.
The Obama administration announced in October that it will no longer prosecute medical marijuana users or suppliers, provided they obey the laws of states that allow use of the drug for medicinal purposes.
Rodriguez said he is often asked by his MS patients about whether there is a benefit to using marijuana.
"What I tell my patients," he said, "is if they want to try it they should try it. They should understand that there is a potential for it to be habit-forming and there may be a potential that they are fooling themselves."
Patricia A. O'Looney, vice president of biomedical research at the National Multiple Sclerosis Society, said the society has studied this issue and does not think enough is known to recommend that MS patients use marijuana.
"Because the studies to date do not demonstrate a clear benefit compared to existing therapy, and issues of side effects and long-term effects are not clear, the recommendation is that it should not be recommended at this time," she said.
Another expert, Dr. William Sheremata, director of the Multiple Sclerosis Center at the University of Miami School of Medicine, also doesn't think MS patients necessarily benefit from marijuana use.
Sheremata noted that the objective measures in the study did not show any benefit from marijuana. "Those are the only valid measures. Subjective responses are subjective; they really don't have much in the way of validity," he said. "I am not convinced that the use of marijuana benefits patients as a whole."
For more information on multiple sclerosis, visit the National Multiple Sclerosis Society.