Digoxin excretion in human breast milk

Abstract

T H E R E A R E N O P U B L I S H E D D A T A regarding excretion of digoxin in human breast milk. Recent reviews of drug excretion in breast milk 1, -~ give neither quantitative information nor any recommendation regarding breast feeding and digoxin therapy. Digoxin is extensively distributed in tissues and is usually at low concentration in plasma, 0.5 to 310 ng/ml? One would therefore predict that digoxin therapy should not be a contraindication to breast-feeding unless the drug concentrates in milk relative to plasma. Digoxin, however, can cause serious toxicity in man, including the newborn infant, ' and certain drugs do appear in breast milk at much higher concentration than in maternal plasma. 2 A recent report demonstrated that in goats, digoxin concentrations were slightly lower in breast milk than in plasma during short-term intravenous infusions of the drug? The present study determined concentrations of digoxin in maternal and infant plasma and, in breast milk, during chronic maternal digoxin therapy.