It is unknown whether acetylcysteine is present in breast milk after its administration to a nursing woman. Because many drugs are excreted through human milk, acetylcysteine should be used with great caution when administered to a woman who breastfeeds her baby. In any case, the decision about its use is responsibility of physician and should not be used by own initiative of the patient.
Available pharmacokinetic data show that the body is free of drug after 30 hours, at which time it is possible resume breastfeeding without any risk.
Warning of the manufacturer:
Because it is unknown if the drug passes to the child through breast milk, it is recommended to administer only under medical supervision during lactation.