The Norwegian multicenter study.

The largest multicenter, double-blind trial comparing piroxicam with naproxen in the treatment of osteoarthritis has recently been conducted in Norway. More than 2,000 patients were enrolled in the 12-week study. Both drugs showed similar efficacy, and serious gastrointestinal side effects occurred in less than 1 percent of the patients taking either agent. These findings are similar to results with other nonsteroidal anti-inflammatory drugs. This study indicates that in the treatment of osteoarthritis, piroxicam is as effective as naproxen and poses no greater risk of serious gastrointestinal side effects.