Double-blind study comparing the long-term efficacy of the COX-2 inhibitor nimesulide and naproxen in patients with osteoarthritis.

This double-blind one-year study compares the long-term efficacy and safety of nimesulide with naproxen in patients with osteoarthritis (OA) of the knee or hip. Patients were randomised to nimesulide 100 mg twice daily (n = 183) or naproxen 250 mg morning, 500 mg evening (n = 187). The primary efficacy variable was change in pain intensity (WOMAC A scale) at 6 months. Nimesulide tablets showed at least equivalent efficacy to naproxen tablets in reducing pain intensity at 6 and 12 months (nimesulide -22.5% at 6 and 12 months; naproxen -22.4% at 6 months, -19.9% at 12 months; non-inferiority proven). At 6 months the investigator assessed efficacy as 'good' or 'excellent' in 59.3% of nimesulide and 56.4% of naproxen-treated patients, with corresponding values for patient assessment of 57% and 52.7%. Both treatments were well tolerated, with fewer related gastrointestinal adverse events reported with nimesulide (77 cases, 47.5%) than with naproxen (96 cases, 54.5%). This study shows nimesulide to be as effective as naproxen in the long-term treatment of OA and to be associated with fewer gastrointestinal side-effects.