Under normal circumstances, breastfeeding mothers can be cautiously taken orally under the guidance of a doctor, and breastfeeding needs to be suspended while taking it. It is mainly used for cough and asthma and cough caused by chronic bronchitis. Among them, chlorpheniramine maleate has dizziness, weakness, drowsiness, diarrhea, abdominal pain, polyuria, petechial hemorrhagic tendency of the skin, as well as adverse drug reactions such as chest tightness, palpitations and heart rhythm. It can also cause extrapyramidal reactions and can cause adverse effects such as agranulocytosis, hemolytic anemia, and thrombocytopenia. Its metabolites can be transmitted to the breastfed child through breast milk, causing drowsiness and abnormal liver metabolism, etc. It can also affect the breastfed child with diarrhea, epigastric pain and extrapyramidal reactions, so it should be used with prudent selection during breastfeeding. If necessary, it should be used under the guidance of a doctor and breastfeeding should be suspended during the application. Breastfeeding mothers should pay attention to breast care, diet and nutrition and good living habits to avoid affecting their health and the normal development of the fetus. First of all, we should pay attention to breast care and do a good job of cleaning to avoid the growth of bacteria that can cause infection.