Safety and Efficacy of Medicinal Cannabis in the Treatment of Fibromyalgia: A Systematic Review.

Fibromyalgia (FMS) is a complex condition that is characterized by various pain syndromes and fatigue, among other symptoms experienced. Current medical treatment of FMS involves both pharmacological and nonpharmacological approaches, but often with ineffective outcomes. Medicinal cannabis has the potential to be a therapeutic option for patients with FMS due to the positive research in chronic pain management. In addition, it has been found to have fewer adverse effects compared with currently available pain medications. This literature review aims at answering whether medicinal cannabis is reported to be safe and effective for the treatment of pain and symptomology experienced by people with FMS. A systematic review was conducted on human trials utilizing cannabis in FMS. MEDLINE, Embase, CINAHL, AMED, Scopus, and Cochrane CENTRAL were used for databases search, and mesh terms were used for cannabis and FMS. The search was limited to studies conducted from 2000 to 2020. From the 181 citations identified, 10 studies were included after title, abstract, and full text screening occurred. A total of 1136 of patients (intervention  = 945, control  = 108, crossover  = 83) participated in the 10 studies ranging from 9 to 383 patients (mean = 114, median = 36). Of these studies, there were three randomized controlled trials, six observational studies, and one study that compared the management of chronic pain patients with FMS patients. Cannabis was found to be safe and well tolerated in FMS. The main adverse events identified included feeling "high," dizziness/vertigo, dry mouth, cough, red eyes, and drowsiness with no serious adverse events reported. This literature review identified that medical cannabis may be beneficial for some people with FMS. Further studies are required to confirm its efficacy, what type of cannabis is the most effective form to use, and what assessment tools need to be utilized to understand how to quantify clinical outcomes.