Absorption of Digoxin in Patients with Malabsorption Syndromes

Abstract

Gastrointestinal absorption of digoxin was evaluated by use of a recently developed radioimmunoassay to measure serum levels. Eleven patients with malabsorption syndrome (nine with malabsorption and two with maldigestion due to pancreatic insufficiency) were compared with a control group of 10 patients who had no intestinal disease. All subjects received 0.25 mg of oral digoxin daily, and steady-state serum levels, reached after six days in all subjects, were determined. The mean steady-state serum digoxin level for the nine patients with malabsorption was significantly less than that for the control group (p less than 0.001), whereas levels for the two patients with pancreatic insufficiency were not significantly different from control values. These data indicate that digoxin is poorly and erratically absorbed by patients with malabsorption on the basis of mucosal defects or hypermotility but may be more normally absorbed by patients with pancreatic insufficiency.