Phenergan and Breastfeeding
It is currently unknown whether Phenergan (promethazine) is safe for breastfeeding women or their infants. It is believed that small occasional doses of the medication will not cause serious problems in an infant. However, before taking Phenergan, breastfeeding women should consult their healthcare providers first, as the drug may decrease breast milk supply.
Even though Phenergan® (promethazine hydrochloride) is an older medication that has been used for decades, it is unknown if it passes through breast milk. Apparently, no laboratory methods can accurately measure Phenergan in breast milk. In general, small occasional doses are not expected to cause serious problems.
It should be noted that this article applies only to Phenergan products that contain only promethazine as the active ingredient. Some cough syrups (such as Phenergan with Codeine) contain other active ingredients as well.
Large or frequent doses of Phenergan could cause problems, such as drowsiness in the infant. However, small occasional doses probably will not cause serious problems. Women who are just beginning to breastfeed, or who are already having trouble with low supply, may need to avoid this medication, since it may decrease the milk supply.
The American Academy of Pediatrics has not rated the safety of Phenergan for use during breastfeeding.
You should talk with your healthcare provider about breastfeeding during Phenergan use. Each woman's situation is different, and you and your healthcare provider understand your situation best. After considering what you want and expect, as well as your current health situation, the two of you can make a shared decision that is right for you.