Ten percent of patients who have fibromyalgia syndrome (FMS) use marijuana for medicinal relief from FMS symptoms (eg, widespread pain, fatigue, and insomnia), according to research findings published in Arthritis Care & Research, an American College of Rheumatology publication. Cannabinoids may offer some therapeutic effect, but because patients who self-medicate with herbal cannabis have poorer mental health, recommendations should be avoided until psychosocial and health issues can be further clarified, it was suggested.
Fitzcharles and colleagues documented self-reported cannabinoid use in 457 patients with FMS being treated at the Alan Edwards Pain Management Unit of the McGill University Health Centre in Montreal. They validated the FMS diagnosis and investigated associations and trends of self-medicating with medical marijuana, prescription cannabinoids, or both. Pain levels were measured using the visual analog scale, and functional ability was assessed with the Fibromyalgia Impact Questionnaire; a psychologist evaluated all patients for previous or current psychiatric conditions according to the Diagnostics and Statistical Manual of Mental Disorder.
Thirteen percent of patients used cannabinoids, with 80% of them using herbal cannabis/marijuana; 24% of cannabinoid users used prescription cannabinoids (eg, nabilone and dronabinol), and 3% used both herbal cannabis and prescription cannabinoids. Those who smoked marijuana consumed up to 6 g; 72% reported using 1 g or less per day.
Herbal cannabis was associated with unstable mental illness, opioid drug-seeking behavior, and male sex in 36%, 17%, and 26% of users, respectively, compared with 23%, 4%, and 7% of nonusers. A 77% unemployment rate was identified in herbal marijuana users, which researchers suggested may be the result of pain control that is ineffective in improving functionality. Some patients are prompted to self-medicate with more nontraditional therapies, such as marijuana, because results with pharmacological treatments for FMS pain are modest, it was noted.