EXCRETION OF INDOMETHACIN IN BREAST-MILK

1 The excretion of indomethacin into breast milk and subsequent exposure of infants was studied in 16 women and seven of their infants. The median milk:plasma ratio in seven patients where there were measurable drug concentrations in both milk and plasma was 0.37. 2 Total infant dose, assuming a daily milk intake of 150 ml kg-1 and 100% absorption, ranged from 0.07% to 0.98% (median = 0.18%) of the weight adjusted maternal dose. 3 Plasma samples were obtained in seven infants. In six of these, indomethacin concentrations were below the sensitivity of the assay (< 20-mu-g l-1), while one infant had a plasma indomethacin concentration of 47-mu-g l-1. 4 No adverse effects due to indomethacin were reported in the infants.