Clinically Meaningful Relief of Osteoarthritis in Randomized Controlled Trials of Diclofenac Sodium 1% Gel

Abstract

PURPOSE: To compare rates of clinically meaningful response in patients with hand and knee osteoarthritis (OA) treated with diclofenac sodium 1% gel (DSG) versus placebo rubefacient gel (PRG). Over-the-counter topical rubefacients are often used in sports medicine but have poor efficacy and are not recommended in evidence-based guidelines for OA (National Institute for Health and Clinical Excellence clinical guideline 59), whereas topical nonsteroidal anti-inflammatory drugs (NSAIDs) are recommended ahead of oral NSAIDs. However, many US physicians lack experience with topical NSAIDs and may be skeptical that they offer meaningful benefit compared with more familiar topical rubefacients. METHODS: In a post hoc analysis, patients from 2 double-blind trials of DSG in knee or hand OA were classified based on Osteoarthritis Research Society International (OARSI) criteria for clinically significant response. Patients were randomized to apply DSG or PRG 4 times daily (hand, 8 g/d/hand for 8 weeks to 2 hands; knee, 16 g/d for 12 weeks to 1 knee). OARSI response was defined as improvement ≥50% and absolute change ≥20 points on 100-point scales measuring pain or physical function, or improvement ≥20% and absolute change ≥10 in ≥2 of the following: pain, global rating of disease, and physical function. RESULTS: Clinically significant improvement was achieved by 56%-71% of patients treating knee OA and hand OA with DSG, which was significantly superior to response rates with PRG at most time points (Table). CONCLUSIONS: DSG provided clinically meaningful improvement in OA pain for the majority of patients with hand or knee OA, and for a significantly greater proportion of patients compared with PRG. Supported by Endo Pharmaceuticals Inc.