The effect of indomethacin on breathlessness in patients with diffuse parenchymal disease of the lung.

We have shown in a previous study that indomethacin reduced breathlessness in normal subjects during exercise. In a double-blind randomized study we have determined the effects of both acute (50 mg) and chronic (25 mg twice daily for 7 days) oral treatment with indomethacin on breathlessness induced by exercise in patients with diffuse parenchymal disease of the lung. The relationship of breathlessness, as measured on a visual analogue scale, to ventilation was not significantly altered by either acute or chronic treatment with indomethacin compared to placebo. There was no significant change in the distance walked in 6 minutes after any of the treatments. Possible explanations for the differing effects on breathlessness observed in normal subjects and in patients are discussed.