Fibromyalgia is a chronic pain syndrome of unknown etiology. The disease is characterized by widespread musculoskeletal pain, fatigue and multiple tender points in the neck, spine, shoulders and hips. An estimated 3 to 6 million Americans are afflicted by fibromyalgia, which is often poorly controlled by standard pain medications.
Fibromyalgia patients frequently self-report using cannabis therapeutically to treat symptoms of the disease, and physicians – where legal to do so – often recommend the use of cannabis to treat musculoskeletal disorders. To date however, there are few clinical trials assessing the use of cannabinoids to treat the disease.
Writing in the July 2006 issue of the journal Current Medical Research and Opinion, investigators at Germany’s University of Heidelberg evaluated the analgesic effects of oral THC in nine patients with fibromyalgia over a 3-month period. Subjects in the trial were administered daily doses of 2.5 to 15 mg of THC and received no other pain medication during the trial. Among those participants who completed the trial, all reported a significant reduction in daily recorded pain and electronically induced pain.
A 2008 study published in the The Journal of Pain reported that the administration of the synthetic cannabinoid nabilone significantly decreased pain in 40 subjects with fibromylagia in a randomized, double-blind, placebo-controlled trial. “As nabilone improved symptoms and was well-tolerated, it may be a useful adjunct for pain management in fibromyalgia,” investigators concluded. A separate 2010 trial performed at McGill University in Montreal reported that low doses of nabilone significantly improved sleep quality in patients diagnosed with the disease.
Previous clinical and preclinical trials have shown that both naturally occurring and endogenous cannabinoids hold analgesic qualities,[8-11]particularly in the treatment of pain resistant to conventional pain therapies. (Please see the ‘Chronic Pain’ section of this book for further details.) As a result, some experts have suggested that cannabinoids are applicable for the treatment of chronic pain conditions such as fibromyalgia, and have theorized that the disease may be associated with an underlying clinical deficiency of the endocannabinoid system.
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 Schley et al. 2006. Delta-9-THC based monotherapy in fibromyalgia patients on experimentally induced pain, axon reflex flare, and pain relief. Current Medical Research and Opinion 22: 1269-1276.
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 Ethan Russo. 2004. Clinical endocannabinoid deficiency (CECD): Can this concept explain therapeutic benefits of cannabis in migraine, fibromyalgia, irritable bowel syndrome and other treatment-resistant conditions? Neuroendocrinology Letters25: 31-39.