[A double blind comparison of naproxen and indomethacin on the after-midnight-pain of patients with morbus bechterew].

27 patients with ascertained ankylosing spondylitis experiencing constant after-midnight-pain received, following three medication-free days, in a double blind, randomized, cross-over fashion indometacin (100 g/day) and d-2-(6'-methoxy-2'-naphthyl)-propionic acid (naproxen) (500 mg/day), as suppositories, for a period of six days each. The intensity of the night-pain was recorded daily. Naproxen was shown to be equally effective as indometacin in alleviating the after-midnight backache of ankylosing spondylitis. Side effects occurred under indometacin in 5 cases, under naproxen in 3 cases.