The effect of indomethacin on the psychomotor function of patients with rheumatic diseases.

We have compared the effect of single and multiple doses of indomethacin and placebo on objective measurements of psychomotor impairment in patients. Following a single 50 mg dose (n = 8), indomethacin produced psychomotor disturbance in only those patients who had no recent history of NSAID exposure. After multiple doses of indomethacin (25 and 50 mg tid for 5 days), significant psychomotor impairment was observed. We conclude that other NSAIDs may induce cross-tolerance to the psychomotor effects of indomethacin. Tachyphylaxis may develop to the psychomotor disturbance caused by indomethacin.