Use of hypoglycemic drugs during lactation

QUESTION My patient was taking glipizide (an oral sulfonylurea) for type 2 diabetes. Now she is pregnant and taking insulin instead. She is very anxious to return to her previous treatment immediately after delivery because of the pain and hurdles associated with the administration of insulin. Can sulfonylureas cross into human milk and, if so, is it safe for her to breastfeed her infant? ANSWER The exposure of infants to second-generation sulfonylureas (eg, glipizide, glyburide) through breast milk is expected to be minimal, based on the limited data available. Women with type 2 diabetes treated with sulfonylureas should not be discouraged from breastfeeding. The benefits of breastfeeding greatly outweigh the risks of these medications, if any. The baby should, however, be monitored for signs of hypoglycemia.