Reduction of indomethacin-induced gastrointestinal blood loss by sodium salicylate in man.

The gastrointestinal bleeding during treatment with indomethacin, aspirin, phenylbutazone and sodium salicylate in healthy human subjects was determined. Gastrointestinal blood loss was determined by the Cr51-labelled erythrocyte method. The method was modified by us. Collected stool was incinerated and radioactivity of ashes was determined. Furthermore, rheumatic patients were treated for 4 weeks with indomethacin alone or with indomethacin combined with sodium salicylate. The gastrointestinal blood loss was determined on the last 4 days of treatment. It was found that blood loss was significantly reduced by combined treatment in comparison to monotherapy with indomethacin, while combined treatment had a marked anti-rheumatic effect.