A clinical trial was conducted in 600 patients with OA of the knee to test the hypothesis that the specific COX-2 inhibitor, celecoxib, has equivalent efficacy and a superior tolerability/safety profile when compared to diclofenac, the current worldwide standard of care.
Patients were administered celecoxib 100 mg BID, diclofenac 50 mg TID or placebo for 6 weeks in a multicentre, double-blind. placebo-controlled trial.
Primary efficacy measures (index joint pain by VAS, WOMAC index) indicated statistically significant improvement versus placebo for both celecoxib and diclofenac and no statistically significant differences between celecoxib and diclofenac. American Pain Society (APS) measures to assess the rapidity of onset of action showed statistically significant and comparable pain relief versus placebo within 24 h for both celecoxib and diclofenac. More diclofenac patients reported GI side effects than patients treated with either placebo or celecoxib. Diclofenac-treated patients experienced statistically significant elevations in mean hepatic transaminases and serum creatinine and reductions in haemoglobin concentration when compared to placebo, events not observed with celecoxib.
Celecoxib 200 mg daily is as effective as diclofenac 150 mg daily for relieving signs and symptoms of OA of the knee, including pain, and has a rapid onset of action. However, celecoxib appears to have a superior safety and tolerability profile.