You can take cough syrup for asthma, but it cannot improve asthma symptoms. 1. Cough syrup is mainly used to reduce the irritation of inflammation on the airway mucosa and relieve coughing, so it can only relieve coughing due to infectious diseases, such as colds, acute bronchitis and so on. 2. Asthma is caused by genetic factors and allergies, so cough syrup has little effect on coughs caused by asthma. 3. Patients with asthma need to be treated with medications such as inhaled glucocorticoids or bronchodilators under the direction of a doctor, commonly used medications such as salmeterol fluticasone or budesonide formoterol. It is recommended that asthma patients seek medical advice in a timely manner, choose the appropriate medication under the guidance of a doctor, and avoid using medication without medical advice. Adhere to the daily application of controlling drugs, always carry emergency relief drugs, avoid contact with allergens.