Treatment of ankylosing spondylitis with oxaprozin: A comparison with indomethacin

Ninety-seven patients with ankylosing spondylitis entered a 6-month multicenter, double-blind study that compared the efficacy and safety of Oxaprozin with those of indomethacin. Fifty-five patients received Oxaprozin (1,200 to 1,800 mg once daily) and 42 received indomethacin (50 to 200 mg in two divided daily doses). Significant (P <.05) mean changes indicative of improvement in the primary efficacy parameters, including observer's and patient's opinion and day and night sacroiliac pain, were observed in both treatment groups at most evaluations. Duration of morning stiffness, activity impairment, and time to walk 50 feet also decreased significantly in both groups at most evaluations. Mean chest expansion scores increased significantly and mean fingertips-to-floor distance decreased significantly at several evaluations among the oxaprozin-treated patients but only rarely among the indomethacin-treated patients. The only significant difference between groups was noted at week 28 in day pain intensity, and this difference favored indomethacin treatment. Nineteen oxaprozin-treated patients (35%) and 11 indomethacin-treated patients (26%) (not significant) withdrew for drug-related reasons, including unsatisfactory response and/or adverse effects. A higher incidence of total CNS disorders (P < .001), dizziness and vertigo (P < .001 ). headache (P < .05), and miscellaneous CNS reactions (P < .01 ) was associated with indomethacin treatment. Gastrointestinal symptoms, such as abdominal pain, nausea, and diarrhea, occurred with comparable frequency (2% to 17%) in both groups. Indomethacin, however, was associated with a greater (P < .05) overall incidence of adverse effects than was Oxaprozin.