Breast-feeding

It is not known whether anastrozole is excreted into breast milk. Because many drugs are excreted in human milk and because of the tumorigenicity shown for anastrozole in animal studies, or the potential for serious adverse reactions in nursing infants, a decision should be made whether to discontinue breast-feeding or to discontinue the drug, taking into account the importance of the drug to the mother. Anastrozole is contraindicated in pre-menopausal females, so use during lactation would not be expected.(12)