Mammary excretion of digoxin in goats

The binding of digoxin to proteins in plasma and milk was about 20% lower after the addition of the drug to plasma and milk (in vitro) than its binding in plasma and milk from animals administered digoxin parenterally. The mammary excretion of digoxin was examined in the experiments on goats. The concentration of non-protein-bound digoxin in milk was slightly lower than the concentration of non-protein-bound in plasma suggesting a passive diffusion. The amount of digoxin excreted with the milk per day should be far below the dose usually recommended for a newborn child.