Evaluation of the efficacy of cannabinoids in the control of chronic pain in patients with fibromyalgia: a meta-analytic review

Abstract

Background: Fibromyalgia (FM) is a neurosensory disorder characterized by chronic musculoskeletal pain, fatigue, and sleep disturbances. Its treatment remains challenging, and conventional therapies are not always effective, which has encouraged the search for alternative therapeutic approaches. Objective: To compare the efficacy of cannabinoids in controlling pain in fibromyalgia with other treatments or placebo. Methods: A systematic review was conducted following the PRISMA guidelines, with searches performed in PUBMED/MEDLINE, BVS, Cochrane Database, Scopus, and Web of Science. Risk of bias was assessed using the RoB 2.0 tool, and the certainty of the evidence was evaluated using the GRADE approach. Results: Of the 94 studies initially identified, only four randomized clinical trials, involving 101 participants, met the inclusion criteria. The methodological analysis revealed significant bias, mainly related to blinding breakdown and outcome selection. In addition, the studies presented high heterogeneity among themselves. Conclusion: Although cannabinoid therapy is considered a potential alternative for fibromyalgia, the current evidence is of low quality and does not demonstrate statistically significant benefits in pain relief for these patients.