Duloxetine for pain in fibromyalgia in adults: a systematic review and a meta-analysis

Objectives: The objective of this systematic review was to assess the analgesic efficacy of duloxetine (DLX) for fibromyalgia (FM) and find out which dosage between 60 mg/d DLX and 120 mg/d DLX was more suitable for clinical application.Methods: A systematic search through multiple databases (Cochrane Central Register of Controlled Trials (CENTRAL), ProQuest, PubMed) was conducted from 2000 until 7 March 2019. All steps were performed by two or more independent reviewers. The meta-analysis was performed to report the effects of DLX on pain reduction and its accompanied adverse events.Results: This meta-analysis, including seven studies with 2642 FM patients, demonstrated that DLX could produce greater pain relief in FM than placebo (standardized mean difference (SMD) -0.26; 95% confidence interval (CI) -0.37 to -0.16). The risk ratio (RR) of at least 30% pain relief was 1.31 (95% CI 1.19 to 1.44); the RR of at least 50% pain relief was 1.46 (95% CI 1.28 to 1.67). However, the patients with DLX who suffered adverse events were more common than the ones with placebo (RR 1.17, 95% CI 1.12 to 1.23). The withdrawal effect included adverse event withdrawal and lack of efficacy withdrawal. The subgroup analyses of withdrawal effects demonstrated that 120 mg/d DLX had a higher incidence (RR 0.96, 95% CI 0.80 to 1.15) than 60 mg/d DLX (RR 0.77, 95% CI 0.63 to 0.93).Conclusions: In general, DLX was a great choice for pain relief in FM. Moreover, 60 mg/d DLX produced less withdrawal effects than 120 mg/d DLX. HighlightsFibromyalgia (FM) is a chronic condition of unknown aetiology, characterized by widespread pain and often associated with other symptoms.Duloxetine (DLX), a serotonin norepinephrine (noradrenaline) reuptake inhibitor (SNRI), is used to treat FM in many countries.DLX can produce greater pain relief in FM than placebo.DLX can bring about more adverse events than placebo.60 mg/d DLX produces less withdrawal than 120 mg/d DLX for FM patients.