Fibromyalgia is a chronic disorder that causes widespread muscle and joint pain. Estimates suggest that about five million adults in the U.S. are diagnosed with the condition each year, with women affected at least eight times more often than men.
The exact cause of the condition is unclear, but it seems that stressful or traumatic life events, such as injuries and viral infections, may play a role. People with fibromyalgia experience symptoms that can range in duration and severity. The main symptoms are pain and fatigue, but other common symptoms include memory problems, sleep disturbances, headaches, temperature sensitivity, and stiffness upon waking. Often, fibromyalgia coexists with another chronic pain condition, such as chronic fatigue syndrome, inflammatory bowel disease, or temporomandibular joint dysfunction.
There is no known cure for fibromyalgia, but a combination of treatments can help patients manage the symptoms. Three medications -- duloxetine (Cymbalta), pregabalin (Lyrica), and milnacipran (Savella) -- have been approved by the U.S. Food and Drug Administration (FDA) as a treatment for fibromyalgia. However, these medications often put patients at risk for a variety of side effects, including serious allergic reactions, suicidal thoughts or behaviors, dizziness, sleepiness, blurred vision, feeling "high," and swelling of the hands, legs, and feet. Thus, there is a need for new treatments that relieve the symptoms of fibromyalgia with fewer side effects.
An online survey of more than 1,300 people with fibromyalgia conducted by the National Pain Foundation revealed that medical marijuana, or cannabis, is more effective than conventional fibromyalgia treatments. Of the patients who reported marijuana use, 62 percent ranked it very effective at relieving their symptoms, 33 percent said it helped a little, and five percent said it did not help at all. In comparison, among those who tried Lyrica, 10 percent ranked it very effective, 29 percent said it helped a little, and 61 percent said it did not help at all. Not only is marijuana more effective, it is also associated with fewer side effects. The only adverse effect shared by Lyrica and cannabis is feeling "high." However, strains of cannabis with lower ratios of tetrahydrocannabinol (THC), the chemical responsible for much of cannabis's psychoactive, or mood-altering, effects, to cannabidiol (CBD), a chemical that modulates these effects, have been shown to relieve pain without affecting cognition.
Research has yet to reveal the exact mechanisms by which the chemicals, or cannabinoids, in cannabis exert their medicinal effects. But evidence suggests that they work on the endocannabinoid system, which mediates several physiological functions, including pain and inflammation. Studies supported by the [National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)](http://www.niams.nih.gov/health_info/Fibromyalgia/# h) suggest that fibromyalgia results when endocannabinoid system imbalances disrupt the feedback loop that inhibits pain signals, causing altered pain processing, or more specifically, increased sensitivity to stimuli that do not normally provoke pain. Perhaps the result of constant pain, these imbalances could also explain why people with fibromyalgia do not respond as well to conventional pain medications.
The cannabinoids in cannabis are structurally similar to endogenous cannabinoids, naturally occurring chemicals that send messages between nerve cells throughout the brain and spinal cord, affecting pain sensation. Because of this similarity, it is hypothesized that they can attach themselves to molecules called cannabinoid receptors on nerve cells and activate them, resetting or blocking pain processing. Research reveals that cannabinoids may provide greater therapeutic effects in combination than alone: a phenomenon termed the entourage effect. Thus, taking the whole cannabis plant may modulate pain better than an oral medicine derived from one or two of cannabis's chemical components.
Evidence for cannabis's therapeutic effects may be mounting, but the FDA has yet to approve cannabis as a safe and effective treatment for fibromyalgia. As a result, many people are being denied access to a potentially life-changing therapy. About 70 percent of the fibromyalgia patients who responded to the National Pain Foundation survey said they had not tried cannabis as a treatment for their symptoms, which is not surprising, given that federal law still classifies marijuana as a Schedule I drug with no medicinal benefit.
Proponents of medical marijuana are lobbying for a change to the law so that the millions of Americans who live with fibromyalgia could legally buy marijuana for personal use from a safe source. Twenty-three states and Washington, D.C. have already legalized smoked marijuana for medicinal purposes. However, a bill decriminalizing cannabis at the federal level has yet to be signed into law. Currently, more than 60 national and international health organizations, including the American Academy of Family Physicians and the American College of Preventive Medicine, support a move towards granting patients immediate legal access to medical marijuana under a physician's supervision. Legalization would enable people with fibromyalgia to manage their symptoms more effectively without worrying about potential legal repercussions.