Maternal Metyrapone Use During Breastfeeding: Safe for the Breastfed Infant.

Context: Metyrapone is an inhibitor of endogenous adrenal corticosteroid synthesis, which has been proven to be a viable option in controlling maternal serum cortisol concentrations during pregnancy. The infant exposure to maternally ingested metyrapone through breast milk is, however, largely unknown.

Case Description: We report the excretion of metyrapone into breast milk and subsequent infant exposure from a lactating woman on 250 mg of metyrapone three times daily.