Long-term use of isosorbide mononitrate may cause adverse reactions such as dry mouth, nausea and vomiting, dizziness and headache, but generally there is no significant harm. Isosorbide mononitrate is a long-acting nitrate anti-angina drug commonly used in clinical practice, which itself has a long duration of action, and not only has a therapeutic effect on angina pectoris caused by coronary heart disease, but also has a preventive effect. Therefore, patients taking the drug for a long time will not appear obvious bad, patients need to strictly follow the doctor’s instructions to avoid drug overdose. However, the drug is contraindicated in patients with acute circulatory failure, allergy to nitro compounds, acute myocardial infarction with low filling pressure, severe hypotension, hypertrophic obstructive cardiomyopathy, severe anemia, glaucoma and so on. The drug itself in the therapeutic effect at the same time, there will be certain adverse drug reactions, patients taking isosorbide mononitrate for a long time may appear dry mouth, nausea and vomiting, dizziness and headache, blood pressure reduction and other adverse reactions, some patients may have blurred vision, rash and other situations. Some patients may also appear drug-resistant, patients need to strictly comply with the medical advice to avoid long-term use of drugs, if resistance occurs, but also under the guidance of the doctor to change the drug treatment. To summarize, long-term use of isosorbide mononitrate is not bad, it is recommended that patients strictly follow the doctor’s instructions to use the drug, the emergence of abnormalities in a timely manner to seek medical attention.