The action of Isosorbide Nitrate Tablets is mainly to dilate the coronary arteries and increase the blood supply to the heart, so it is mainly used to improve the symptoms of coronary heart disease, such as angina pectoris attack to use this drug to help relieve the symptoms of angina pectoris. It also dilates the veins, reduces the amount of blood returned to the heart and reduces the preload of the heart, and is especially suitable for the treatment of right heart insufficiency. The main side effect is headache, which will be gradually relieved by timely discontinuation of the drug. It also has a certain effect of lowering blood pressure, so it is not suitable for patients with low blood pressure, but severe hypotension is rare. Other side effects are relatively rare, such as dizziness, drowsiness, nausea, vomiting, skin allergy, and in rare patients, exfoliative dermatitis.