Comparison of the efficacy and safety of naproxen CR and nabumetone in the treatment of patients with osteoarthritis of the knee

Objective: To compare the safety and efficacy of naproxen CR (1,000 mg once daily) with that of nabumetone (1,000 mg once daily) in the treatment of patients with symptomatic knee osteoarthritis (OA). Methods: A total of 159 Korean patients (80 in the naproxen CR group and 79 in the nabumetone group) were enrolled in this 4-week, single-blind, controlled, randomized, parallel study and an intention-to-treat model was used for data analysis. Six efficacy parameters were measured: Lequesne index, visual analogue pain scale at rest and at activity, patient's and physician's global assessment, and time to walk 50 feet. Results: Significant improvement in all efficacy parameters except time to walk 50 feet occurred at Week 2 and Week 4 in both groups. The mean improvement from baseline at Week 2 and Week 4 for the efficacy variables was not different between naproxen CR and nabumetone group. Twenty-four patients (30%) in the naproxen CR group and 18 patients (22.8%) in the nabumetone group withdrew from the study. Among them, only 1 patient in the naproxen CR group terminated the study prematurely due to an adverse event of dyspepsia. No statistically significant difference in the frequency of adverse events, including gastrointestinal symptoms, was observed between these 2 groups during the treatment period. Significant laboratory abnormalities also did not occur during the study period in both groups. Conclusions: Naproxen CR is an effective and tolerable drug in the treatment of knee OA. Efficacy and safety profiles are comparable to those of nabumetone.