Double-blind trial of naproxen and phenylbutazone in ankylosing spondylitis

In a double-blind double-placebo crossover study naproxen (500-750 mg daily) was found to be equivalent to phenylbutazone (400-600 mg daily) in the control of disease activity in 20 patients suffering from ankylosing spondylitis during a two times 5-week trial period. No serious side effects were observed during the trial period. Gastric complaints occurred twice as often under phenylbutazone as under naproxen.