When administered orally or intravenously, it is excreted into breast milk in clinically non-significant amount which is very lower than that prescribed to infants. This medication is authorized for use in infants older than 1 month of age. Be aware of the possibility of false negative results of bacterial cultures done to infants when the mother is on antibiotics, together with a higher risk of diarrheal disease due to imbalance of intestinal flora. When topically used with creams and vaginal ovules, absorption into serum is scanty, hence, excretion into breast milk is believed lower than that attained by systemic administration.