Perspectives on digoxin absorption from small bowel resections

Digoxin is a commonly prescribed medication for a variety of cardiovascular abnormalities. The therapeutic index of digoxin is considered narrow and drug is absorbed predominantly from the duodenum and upper jejunum. When the small intestine is intact, the absorption can vary; therefore, in the case of a small bowel resection or bypass, this erratic absorption may be accentuated. There is some controversy concerning the effect of small bowel resection or bypass on the absorption of digoxin. Some investigators have shown that small bowel resection or bypass decreases the absorption of oral digoxin, whereas others report no change in absorption. When the study methodologies were evaluated, certain common factors that support each view were found. In most studies reporting malabsorption, a solid dosage form of digoxin was used. Studies reporting no change in absorption investigated a solution dosage form.