Enterohepatic circulation of sulindac and metabolites

Abstract
Four subjects were studied by continuous intraduodenal sampling to establish the existence and determine the extent of enterohepatic recirculation of sulindac [nonsteroidal antiinflammatory drug] and its sulfide and sulfone metabolites. Sulindac, 200 mg by mouth, was given every 12 h for 7 days. After the last dose was given intraduodenally, constant duodenal infusion of a nutrient mixture and sampling of duodenal contents were performed through a triple-lumen intraduodenal tube for 12 h. Calculation of nonabsorbed drug in the samples and quantitation of drug and metabolite levels in the biliary secretions were made possible by nonabsorbable markers in the drug solution and in the infusate. Interindividual variations in the absolute values for each of the chemical species were over a 200% range, but for each subject relative clearances were in a remarkably constant ratio, averaging 1:12:12 for sulfide:sulindac:sulfone. Total biliary excretions of the prodrug (sulindac) and active pharmacophore (sulfide) calculated from these biliary clearances and historic mean plasma AUC [area under the concentration-time curve] were 136 and 22% of dose. There is a correlation between data in man and 5 other species and the data established that, after sulindac, the contribution of enterohepatic circulation to conservation of the active pharmacophore is achieved predominantly at the level of inactive prodrug.

This publication has 3 references indexed in Scilit: