At usual doses, ketoconazole is considered compatible with breastfeeding.
There is a very limited amount of published observations on this subject. As is known, ketoconazole has considerable influence CYP3A4 and toxic potential, so it is better to use other therapeutic agents. However, in the event of its administration deems appropriate, it is not necessary to stop breastfeeding, recommending in these cases taking the dose of ketoconazol just before baby's longer sleep phase, leaving a minimum of 3-5 hours until the next feeding of breastmilk.
Topical application of ketoconazole (cream, gel, shampoo) the mother has an even lower risk of producing disorders in infants.
Warning of the manufacturer:
Ketoconazole is excreted in milk, so women undergoing treatment does not shall use breastfeeding.