February 18, 2008
Science Daily/American Pain Society
Patients with fibromyalgia treated with a synthetic form of marijuana, nabilone, showed significant reductions in pain and anxiety in a first-of-its-kind study, published in The Journal of Pain.
Fibromyalgia syndrome has no cure, is difficult to diagnose, and effective pain management strategies are a must to help patients cope with the disease. An estimated 12 million Americans have fibromyalgia, which is characterized by widespread muscle and joint pain and myriad other symptoms. The condition is far more prevalent in women and the incidence increases with age, reaching 7 percent among women 65 years and older.
Forty subjects were selected for the nabilone trial, conducted by researchers at the University of Manitoba Rehabilitation Hospital. They were divided into nabilone and placebo groups and were treated for four weeks. The authors noted this was the first randomized, controlled-access trial to evaluate nabilone for pain reduction and quality-of-life improvement in fibromyalgia patients. Nabilone is one of two oral marijuana-based compounds, known as cannabinoids, available in Canada and is approved for treatment of nausea and vomiting during chemotherapy.
Results of the Manitoba study showed the nabilone group had significant reductions in pain and anxiety, measured by comparisons with baseline scores on the visual analogue scale for pain, the Fibromyalgia Impact Questionnaire (FIQ) and the FIQ anxiety score. From the data, the study concluded nabilone has significant benefits for pain relief and functional improvement in fibromyalgia patients. Although the improvement was significant, none of the nabilone-treated subjects had complete relief of their fibromyalgia symptoms.
The drug was well tolerated by treated patients, which the authors characterized as reassuring since fibromyalgia patients are sensitive to most medications and have difficulty tolerating side effects. The downside, however, is cost. In Canada, nabilone would cost about $4,000 for a year's supply.