Efficacy and Safety of Duloxetine for the Treatment of Osteoarthritis: Systematic Review and Meta‐Analysis

Background Osteoarthritis (OA) is a common illness that is widespread globally, especially among individuals aged 65 and older. Since 2019/2020, the OARSI and ACR recommendations have included the use of medicines such duloxetine, which function as analgesics for pain patients including central sensitization. Recent studies have assessed duloxetine as an adjunctive treatment in decreasing OA pain. Objective Assess the effectiveness and safety of duloxetine in treating OA pain in adults aged 40 and above. Methods We conducted a systematic review and meta‐analysis of randomized clinical trials. The scientific evidence search was conducted in the following databases: MEDLINE via PubMed, Cochrane Library, Embase, LILACS, Web of Science, Scopus, CINAHL, ProQuest, SciELO, and Google Scholar. Findings The systematic review comprised nine randomized controlled trials (RCTs). The studies showed that using duloxetine for OA treatment was more effective than a placebo in achieving a 50% pain reduction (RR = 1.57, 95% CI = 1.31; 1.89) and a 30% pain reduction (RR = 1.41; 95% CI = 1.29; 1.55). This improvement was observed in pain, physical function, and stiffness as measured by the WOMAC subscales, as well as in the CGI‐SEVERITY scale and the AUSCAN functional index. Duloxetine was found to be more effective than gabapentin and acetaminophen in treating moderate to severe knee OA, as it decreased ratings on the whole WOMAC scale and its subscales for pain, physical function, and stiffness. There was no statistically significant difference in adverse events between duloxetine and gabapentin, both of which were more effective than acetaminophen, which did not cause any adverse events. Conclusion This systematic review indicates that duloxetine is an effective treatment for pain in OA in adult patients over 40 years old, with a reasonable level of safety when compared to other centrally acting medications and placebo.