Dextromethorphan Syrup is mainly composed of dextromethorphan hydrobromide and guaiacol glyceryl ether, and its main function is to suppress cough and expectorant. For the treatment of cough and phlegm caused by upper respiratory tract infections, also known as colds, pharyngitis caused by cough and phlegm have a certain therapeutic effect. For the lower respiratory tract infections, such as bronchitis acute attack or chronic bronchitis acute attack, pneumonia caused by cough and cough sputum also has a certain effect. However, the side effects of dextromethorphan syrup are still relatively many, after taking the drug, some people will have dizziness and headache phenomenon, drowsiness is more common, prone to digestive symptoms, such as loss of appetite, belching, constipation, nausea, and some people may also have allergic reactions, but after stopping the drug, these symptoms are basically can disappear. If the symptoms are not relieved after taking the drug for 2-3 days, you should go to the hospital for specific examination.