Effect of cholestyramine on digoxin absorption and excretion in man.
Six subjects receiving digoxin therapy for heart disease were studied on two occasions with a single oral dose of 0.5 mg of tritiated digoxin. In every study, all stools and urine were saved for 1 week. Before the second study, treatment with cholestyramine, 4 g every 6 hours, was begun and continued throughout. In three patients, a third study was performed after cholestyramine treatment had been continued for 1 month. Results showed that after cholestyramine administration serum levels, stool output and urinary output of tritiated digoxin varied over a wider range, but cholestyramine had no net short-term effect of any of these variables. After 1 month of cholestyramine administration, there was a small statistically significant increase in stool output of tritiated digoxin and metabolites. In vitro studies suggested that cholestyramine is likely to be a weak digoxin binder in the gut and that changes induced by this resin in digoxin metabolism are not likely to be due to drug binding.
D000284:Administration, Oral; D001665:Binding Sites; D002792:Cholestyramine Resin / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D002908:Chronic Disease; D004077:Digoxin / Q000008:administration & dosage / Q000378:metabolism* / Q000627:therapeutic use; D004347:Drug Interactions; D004359:Drug Therapy, Combination; D006331:Heart Diseases / Q000188:drug therapy; D006801:Humans; D066298:In Vitro Techniques; D007408:Intestinal Absorption / Q000187:drug effects; D008297:Male; D013997:Time Factors
D002792:Cholestyramine Resin; D004077:Digoxin