Effect of pharmacotherapy on fibromyalgia: an overview of systematic reviews

Abstract

Fibromyalgia is a debilitating and chronic pain processing disorder, in which the proportion of patients who achieve good results with pharmacotherapy is small. However, choosing the best available evidence on pharmacotherapy can optimize patient clinical outcomes. Objective: This overview aimed to identify in systematic reviews the effects of pharmacotherapy on fibromyalgia, considering the quality of the reviews and the efficacy of the outcomes. Methods: This search was performed in seven databases: PubMed, Web of Science, COCHRANE, Lilacs, Embase, Scopus and IPA. The methodological quality was evaluated using A MeaSurement Tool to Assess Systematic Reviews 2. The protocol was registered in the PROSPERO database (CRD42018095943). Results: A total of 63 systematic reviews were selected after reading full texts, but only 8 of them were of moderate to high quality and were included in this overview. All included reviews were published in English, between 2012 and 2018, performed meta-analysis, used the American College of Rheumatology (1990) diagnostic criteria for fibromyalgia, and jointly assessed pain improvement, adverse reactions, and withdrawal. Most reviews included only randomized controlled trials. Of the fourteen drugs addressed in systematic reviews evaluated, duloxetine, milnacipran, and pregabalin showed evidence of improvement in pain (Moderate:≤30%) and other fibromyalgia symptoms, as depression and fatigue. However, these medications presented significant withdrawals due to adverse reactions (mainly nausea, headache, dizziness and constipation). The rate of treatment withdrawal reached 36%. Conclusion: Few studies have high quality and sufficient evidence on the effect of medicines on fibromyalgia, resulting in a lack of support for prescribers to choose drugs that meet criteria for need, effectiveness, safety and compliance.