A Meta-analysis of Controlled Clinical Studies With Diacerein in the Treatment of Osteoarthritis

BACKGROUND: This systematic meta-analysis on randomized controlled trials with diacerein was performed to provide an evidence-based assessment of its symptomatic efficacy in the treatment of osteoarthritis. METHODS: Electronic databases were searched for randomized controlled trials with diacerein. A manual review of the literature, abstracts, and posters was also conducted. Unpublished final reports were obtained from the manufacturer. Only studies performed in knee and/or hip osteoarthritis were chosen for review. Study inclusion, quality scoring, and data extraction were performed by 2 reviewers independently. Objectives for analysis comprised pain, function, escape medication use, global efficacy, and safety ratings by patients and investigators. Specific study periods, such as the active treatment period and the treatment-free follow-up period (when present), were analyzed. Statistical analyses were based on the intention-to-treat principle as far as possible, and acknowledged tests were used for data analysis. RESULTS: A total of 23 studies were identified, 19 of which were included. Diacerein was significantly superior to placebo during the active treatment phase (Glass score, 1.50 95% confidence interval, 0.80-2.20). Both diacerein and nonsteroidal anti-inflammatory drugs (NSAIDs) were similarly efficacious during the treatment period; however, diacerein, but not NSAIDs, showed a carryover effect, persisting up to 3 months after treatment, with a significant analgesic-sparing effect during the follow-up period (Glass score, 2.06 95% confidence interval, 0.66-3.46). Tolerability assessment revealed no differences between diacerein and NSAIDs, although the latter showed more severe events. CONCLUSION: This systematic meta-analysis provides evidence for the symptomatic efficacy of diacerein in the treatment of knee and hip osteoarthritis, with reasonable tolerability.