Isosorbide mononitrate tablets and extended-release tablets do not have which is good, depending on the patient’s condition suitable for which drugs, follow the doctor’s instructions to use the right medicine is the best. Isosorbide mononitrate tablets and isosorbide mononitrate extended-release tablets is the same kind of medicine, the basic pharmacological effect is the same, the main ingredient isosorbide mononitrate, both can be used for coronary heart disease, myocardial infarction, angina pectoris, chronic congestive heart failure, and the two therapeutic effects are similar. However, isosorbide mononitrate tablets and extended-release tablets have certain differences, and their onset of action time is not the same. Isosorbide mononitrate tablets belong to the short-acting coronary artery expansion, improve the blood supply of the heart of the drug, isosorbide mononitrate tablets of the amount of medicine into the body soon released; and isosorbide mononitrate extended-release tablets belong to the long-acting class of drugs, the amount of its medicine is slowly released. Some patients may experience adverse reactions such as facial flushing, dizziness, hypotension, and tachycardia after taking isosorbide mononitrate tablets or extended-release tablets. Contraindications for both isosorbide mononitrate tablets and extended-release tablets include those with severe hypotension, patients with hypertrophic obstructive cardiomyopathy, patients with pericardial tamponade, as well as those with increased intracranial pressure, glaucoma, and nitrocompound hypersensitivity. Therefore, patients should follow the doctor’s instructions according to their own condition to choose the right drug, not blindly compared, do not take the drug, so as not to affect the efficacy and produce unnecessary adverse reactions.