Meclofenamate sodium in the treatment of ankylosing spondylitis. Report of a European double-blind controlled multicenter study.

98 patients with reversible, definite, active ankylosing spondylitis were selected for this study. 49 patients were treated with N-(2,6-dichloro-m-tolyl)anthranilic acid, sodium salt (meclofenamate sodium, Meclomen) and 49 patients with indometacin. Following a single-blind baseline period on placebo, patients received either 200 mg meclofenamate sodium per day or 100 mg indometacin per day for one week, in the second week the doses were increased to 250 mg meclofenamate sodium and 125 mg indometacin and from the third through the eight week 300 mg meclofenamate sodium and 150 mg indometacin were given. The results of this double-blind study showed that similar improvement in mobility of the vertebral column and spondylitic pain could be achieved with meclofenamate sodium and indometacin in patients with ankylosing spondylitis. Although both treatments were well tolerated fewer meclofenamate sodium patients reported adverse reactions than did those who had received indometacin. It is concluded that meclofenamate sodium offers an effective and safe alternative to indometacin in the treatment of patients with ankylosing spondylitis.