Tritiated digoxin. XIV. Enterohepatic circulation, absorption, and excretion studies in human volunteers

Metabolic turnover studies performed on six patients with surgically induced biliary fistula given tritiated digoxin reveal virtually all stool excretion of digoxin to be derived from bile. This establishes the relative lack of recycling of digoxin as an important factor in digoxin metabolism. This is probably related to its polar chemical structure and is a determinant of its clinical duration of action in human subjects. The amount of digoxin in the enterohepatic circulation (recycling) was calculated to be 6.5% of the administered dose and absolute absorption to be 85% in human subjects.