Safety of Topical Non-steroidal Anti-Inflammatory Drugs in Osteoarthritis: Outcomes of a Systematic Review and Meta-Analysis

ObjectiveWe aimed to assess the safety of topical non-steroidal anti-inflammatory drugs (NSAIDs) in the management of osteoarthritis (OA) in a systematic review and meta-analysis of randomized, placebo-controlled trials.MethodsA comprehensive literature search was undertaken in the MEDLINE, Cochrane Central Register of Controlled Trials (CENTRAL), and Scopus electronic databases. Randomized, double-blind, placebo-controlled, parallel-group trials that assessed adverse events (AEs) with topical NSAIDs in patients with OA were eligible for inclusion. Authors and/or study sponsors were contacted to obtain the full report of AEs. The primary outcomes were overall severe and serious AEs, as well as the following MedDRA System Organ Class (SOC)-related AEs: gastrointestinal, vascular, cardiac, nervous system, skin and subcutaneous tissue, musculoskeletal and connective tissue.ResultsThe search strategy identified 1209 records, from which 25 papers were included in the qualitative synthesis and 19 were included in the meta-analysis, after exclusions. Overall, more total AEs (odds ratio [OR] 1.16, 95% confidence interval [CI] 1.04-1.29; I-2=0.0%) and more withdrawals due to AEs (OR 1.49, 95% CI 1.15-1.92; I-2=0.0%) were observed with topical NSAIDs compared with placebo. The same results were achieved with topical diclofenac, largely driven by an increase in skin and subcutaneous tissue disorders (OR 1.73, 95% CI 0.96-3.10), although the difference was not statistically significant compared with placebo. No significant difference in the odds for gastrointestinal disorders was observed between topical NSAIDs and placebo (OR 0.96, 95% CI 0.73-1.27).ConclusionsTopical NSAIDs may be considered safe in the management of OA, especially with regard to low gastrointestinal toxicity. The use of topical NSAIDs in OA should be considered, taking into account their risk: benefit profile in comparison with other anti-OA treatments.