Systemic ketoconazole is excreted in breast milk. In a case report of one mother prescribed 200 mg PO daily for 10 days, ketoconazole milk concentrations of micrograms/ml (peak) were observed hours post-dose and were undetectable at 24 hours post-dose. Assuming a milk intake of 150 ml/kg/day, the author calculated the daily ketoconazole dose of an exclusively breast-fed infant at mg/kg/day or % of the mother's weight-adjusted dose. The manufacturer recommends mothers refrain from nursing their infants during oral therapy; however, the American Academy of Pediatrics (AAP) considers ketoconazole compatible with breast-feeding. There are no adequate and well-controlled studies of topical use in nursing women; however, ketoconazole is not detected in plasma after chronic shampooing on the scalp. If the topical gel is used during breast-feeding and is applied to the chest, care should be taken to avoid accidental ingestion by the infant. Fluconazole may be a potential alternative to consider during breast-feeding. However, site of infection, patient factors, local susceptibility patterns, and specific microbial susceptibility should be assessed before choosing an alternative agent. Consider the benefits of breast-feeding, the risk of potential infant drug exposure, and the risk of an untreated or inadequately treated condition. If a breast-feeding infant experiences an adverse effect related to a maternally ingested or administered drug, health care providers are encouraged to report the adverse effect to the FDA.