Pharmacokinetics data (low oral bioavailability, high volume of distribution and high protein-binding capacity) explains the scanty excretion into breast milk observed in nursing mothers who received this medication. In addition, a poor oral absorption would make even more difficult any pass of this drug through ingested milk to the infant's blood, except in newborns or premature who would show a higher intestinal absorption. Avoid using in prematures who are under treatment with caffeine or theophylline because terbinafine alters its metabolic degradation and increases plasma concentration. Since topical absorption is less than 1%, a significant excretion into breast milk after application on skin is not expected. Do not use on the breast to prevent ingestion by the infant, otherwise apply after a meal and wipe it out thoroughly with water before next feeding. It is recommended to avoid using on the nipple creams, gels and other products intended for use on skin that may contain paraffin (mineral oil) in order to keep from absorption the infant.