Comparing the efficacy and safety of duloxetine and amitriptyline in the treatment of fibromyalgia: overview of systematic reviews

Background Duloxetine and amitriptyline are antidepressants used in the treatment of fibromyalgia. In published systematic reviews, there is no agreement about which drug is more effective and safer. This study aimed to compare evidence of the efficacy and safety of duloxetine compared with amitriptyline in the treatment of adult patients with fibromyalgia. This work contributes to guiding clinicians on the use of duloxetine or amitriptyline for the treatment of fibromyalgia and provides information for public health decision-makers. Methods Overview of systematic reviews of clinical trials comparing duloxetine and amitriptyline in the treatment of fibromyalgia. The reviews were screened in Cochrane, PubMed, EMBASE, and SRDR with no restrictions on language and year of publication, considering that the research was conducted in July 2018 and updated until May 2020. The selection was based on the following criteria: adult patients with a diagnosis of fibromyalgia treated with duloxetine or amitriptyline, comparing the efficacy and safety in pain, fatigue, sleep, and mood disorder symptoms and quality of life, in addition to the acceptability of these antidepressants. The methodological quality and strength of evidence were assessed using the AMSTAR and GRADE instruments. Results Eight systematic reviews were selected. Amitriptyline had low evidence for pain, moderate evidence for sleep and fatigue, and high evidence for quality of life. Duloxetine had high quality of evidence in patients with mood disorders. With low evidence, duloxetine has higher acceptability, but is safer in older patients, while amitriptyline is safer for non-elderly individuals. Conclusion Both antidepressants are effective in the treatment of fibromyalgia, differing according to the patient's symptoms and profile. Registration PROSPERO: CRD42019116101. Keywords: Fibromyalgia, Duloxetine, Amitriptyline, Systematic review, Overview