Marijuana derivatives or “cannabinoids” taken for one year for the treatment of multiple sclerosis (MS) may reduce muscle spasms and other aspects of disability, results of a UK study suggest.

Dr. J. P. Zajicek, from Peninsula Medical School in Plymouth and colleagues previously reported that cannabinoids taken for 14 weeks appeared to improve mobility and patients’ perception of their MS symptoms. In an extension study, 80 percent of subjects agreed to continue on the medication for up to 52 weeks. The results are reported in the Journal of Neurology, Neurosurgery and Psychiatry.

The analysis included more than 500 patients who were randomly assigned to receive various cannabinoids or an inactive “placebo.”

Treatment with delta-9-THC, a synthetic cannabinoid, seemed to relieve muscle spasms. In addition, patients treated with this drug and other cannabinoids reported improvements in sleep and pain.

Zajicek’s group concludes that “there is now an urgent need to construct a long-term study in progressive MS to establish whether delta-9-THC has a role in long-term disease.”

Dr. J. Killestein and Dr. B. M. J. Uitdehaag, writing in a related editorial, agree with Zajicek’s team about the need for more long-term trials.

The editorialists, from VU Medical Centre in Amsterdam, the Netherlands, add that “these trials should also focus on different cannabinoid products.”

SOURCE: Journal of Neurology, Neurosurgery and Psychiatry, December 2005.