Objective: To compare the clinical efficacy of rofecoxib, a specific inhibitor of cyclooxygenase 2 (COX-2), with that of diclofenac in patients with osteoarthritis (OA) and to evaluate the safety and tolerability of rofecoxib.
Methods: We performed a randomized, double-blind, active comparator-controlled trial in 784 adults with OA of the knee or hip. Patients were randomized to 1 of 3 treatment groups: 12.5 mg of rofecoxib once daily, 25 mg of rofecoxib once daily, and 50 mg of diclofenac 3 times daily. Clinical efficacy and safety were evaluated over a 1-year continuous treatment period.
Results: Rofecoxib at dosages of 12.5 and 25 mg demonstrated efficacy that was clinically comparable to that of diclofenac, as assessed by all 3 primary end points according to predefined comparability criteria. Results from secondary end points were consistent with those of the primary end points. There were small statistical differences favoring diclofenac for 2 of the end points. All treatments were well tolerated.
Conclusion: Rofecoxib was well tolerated and provided efficacy that was clinically comparable, according to predefined statistical criteria, to that of 150 mg of diclofenac per day in this 1-year study. Specific inhibition of COX-2 provided therapeutic efficacy in OA.