Glucose and citrate reduce the permeability changes caused by indomethacin in humans

Nonsteroidal anti-inflammatory drug (NSAID)-induced increased intestinal permeability appears to be a prerequisite for NSAID enteropathy. It has been suggested that early metabolic events leading to the permeability changes may involve inhibition of glycolysis and the tricarboxylic acid cycle, in which case the coadministration of glucose and citrate (the substrates for these metabolic pathways) with indomethacin may afford some protection. The present study, using a combined intestinal absorption-permeability test including 3-O-methyl-D-glucose, D-xylose, L-rhamnose, and [51Cr]ethylene-diaminetetraacetic acid (EDTA) as test probes and the differential urine excretion ratio of [51Cr]-EDTA/L-rhamnose, showed that indomethacin (50 + 75 mg) increased intestinal permeability. A formulation of indomethacin containing 15 mg glucose and 15 mg citrate to each milligram of indomethacin did not increase intestinal permeability significantly above baseline values. When given alone with indomethacin, neither glucose nor citrate (45 mg to each milligram of indomethacin) had any protective effects. Pharmokinetic studies showed that the effects of glucose and citrate cannot be explained on the basis of altered drug absorption. These results suggest a new approach to reducing the small intestinal side effects of NSAIDs.