For a five-month-old baby with a cough, the choice of medication should be made under the guidance of a doctor. If the cough is not very strong, you can take oral Aizhuang. If the cough is more frequent, you can take oral cough syrup such as Etanercept, Xanax, etc. If there is phlegm, you can take Mucosolvan orally to dissolve the phlegm. If the cough increases and is deep, you should have your doctor listen to your lungs. If a lung infection is suspected, a chest x-ray should be done. If bronchopneumonia occurs, anti-infective treatment should be given considering the possible pathogens. If the condition is more severe, intravenous antibiotic therapy is required. In addition, nebulization is more direct and effective when coughing. The nebulized medication acts directly on the airway and the baby’s sputum will be thinner and easier to cough up. The above is for reference only. Please refer to the doctor’s instructions for specific medication and treatment.