Do non-steroidal anti-inflammatory drugs increase colonic permeability?

Urinary excretion of orally administered lactulose and 51 chromium labelled ethylenediamine tetra-acetate (51Cr-EDTA) was measured in 12 healthy adult subjects and in six patients with ileostomies to assess intestinal permeability. In normal subjects, 24 hour urinary recovery of 51Cr-EDTA was significantly greater than that of lactulose (mean (SEM) 2.27 (0.15) v 0.50 (0.08)% oral dose; p less than 0.001), but in ileostomy patients recovery of the two markers was the same. In normal subjects, therefore, the difference between the two markers may arise from bacterial break-down of lactulose but not of 51Cr-EDTA in the distal bowel, urinary excretion of lactulose representing small intestinal permeation and that of 51Cr-EDTA representing both small and large intestinal permeation. The markers were then given simultaneously to nine patients receiving non-steroidal anti-inflammatory drugs (NSAIDs) for rheumatoid arthritis and osteoarthritis. The 24 hour urinary recovery of 51Cr-EDTA in the patients was significantly greater than normal (4.64 (1.20) v 2.27 (0.15)% oral dose; p less than 0.01), but that of lactulose was not significantly affected. Moreover, the increase in 51Cr-EDTA recovery was most noticeable in the later urine collections. Both of these findings suggest that NSAIDs may increase colonic permeability.