Theophylline extended-release tablets do not have a maximum of a few days to take the statement, there is no specific course of treatment, should be based on the patient’s specific condition to determine the time to take. Theophylline extended-release tablets are suitable for the relief of wheezing symptoms in bronchial asthma, wheezing bronchitis, obstructive emphysema, etc.; they can also be used for asthma caused by cardiogenic pulmonary edema. Usually, patients with acute exacerbations can stop the drug when their symptoms are relieved. However, patients with chronic diseases need to take it for a long time. Nausea and vomiting, insomnia, tachycardia and other adverse effects may occur. It is contraindicated in patients who are allergic to this drug, as well as in patients with active peptic ulcers and uncontrolled convulsive diseases. In addition, it should be noted that the therapeutic and toxic doses of the drug are close to each other, and it is recommended to monitor blood levels to avoid drug poisoning. It is recommended that patients take theophylline extended-release tablets under the supervision of a doctor, and not use them on their own, blindly.