Most week-long coughs and stuffy noses are caused by viral infections, which antibiotics cannot cure. Ascoril LS (containing levosalbutamol, ambroxol, and guaifenesin) helps ease his breathing and clear mucus. Since his stuffy nose only happens when he sleeps, try elevating his head slightly or using saline nasal drops before bed. Please consult his pediatrician before starting any antibiotics, as they are only necessary if a bacterial infection is present. Seek immediate medical care if he has trouble breathing, a high fever, or seems very lethargic.