Nonsteroidal antiinflammatory drug-induced small intestinal inflammation and blood loss. Effects of sulfasalazine and other disease-modifying antirheumatic drugs.

Objective: To identify the source of intestinal blood loss in rheumatoid arthritis patients being treated with nonsteroidal antiinflammatory drugs (NSAIDs) and assess the response to sulfasalazine and other disease-modifying antirheumatic drugs (DMARDs).
Methods: Intestinal inflammation, blood loss, and gastroduodenal damage, and the response to treatment with DMARDs, were assessed in 46 patients taking NSAIDs.
Results: Intestinal inflammation and blood loss correlated significantly with one another (r = 0.43, P < 0.003), but not with the macroscopic or microscopic appearance of the gastroduodenal mucosa. Sulfasalazine reduced both intestinal inflammation and blood loss, whereas the other DMARDs did not.
Conclusion: The small intestine is the main site of mild chronic blood loss in patients receiving NSAIDs, and this blood loss can be reduced with sulfasalazine treatment.