The Excretion of Rosaramicin in Breast Milk

Abstract

The excretion of rosaramicin, a macrolide antibiotic, was studied in the breast milk of ten lactating women. Breast milk and serum samples were collected for 48 hours after a single 250‐mg oral dose of rosaramicin. Mean serum half‐life, apparent volume of distribution, and oral clearance were 4.4 hours, 3.41 L/kg, and 6.34 mL/min/kg, respectively. Mean milk/serum ratio was 0.12 and the total amount of drug recovered over the first ten hours was 6.25 μg, approximately 0.0025% of the dose. A positive correlation between breast milk volume and breast milk clearance was found, suggesting that the amount of drug received by a nursing infant will depend on the volume of milk produced by the mother. Drug‐induced toxicity from the parent drug is unlikely to occur in nursing infants since the amount of rosaramicin that a nursing infant could ingest is small.