Theophylline extended-release tablets are best taken after meals. Theophylline, as an effective bronchodilator, is widely used in clinical practice. Theophylline extended-release tablets have been widely used in clinical practice due to its advantages of stable gastrointestinal absorption, relatively constant blood concentration and less frequent dosing with a low incidence of adverse reactions. Its half-life is 10h, and it can be administered twice daily. However, the most common adverse reactions to theophylline extended-release tablets are gastrointestinal reactions, clinically manifested as nausea and vomiting, abdominal pain and diarrhea. Taken before meals will affect the patient’s appetite, so it is recommended to consume after meals to reduce the stimulation of the drug on the gastrointestinal tract. Special attention should be paid to the fact that theophylline extended-release tablets should not be chewed, but should be taken as a whole tablet. It is forbidden to use it if you are allergic to the drug. If you suffer from respiratory diseases, you should consult a doctor or follow the doctor’s instructions when using the drug, do not use the drug without authorization, so as not to cause adverse consequences.