Codeine oral solution is mainly used in clinical practice for stubborn recurrent dry cough, for example, for patients with tuberculous pleurisy, when the lesion involves the pleura and the patient has recurrent stubborn dry cough, using the drug to relieve the symptoms. The use of this drug to suppress cough in patients with hemoptysis can reduce the coughing action and avoid bleeding, but the use of this strong cough suppressant is not recommended for patients with large and sticky sputum, because the suppression of cough can lead to blockage of the airway due to the inability to expel the sputum at the same time. In addition, it can also lead to lung infections that do not improve. Some patients may experience dry mouth and constipation after using this drug, and palpitations may also occur. Pregnant women and children, who are special groups, must be cautious when using this drug, which is a cautionary drug and can only be purchased with a doctor’s prescription.