Gastrodia, also known as isosorbide nitrate, is a representative drug of nitrate anti-angina with nitroglycerin. It is still the first choice for the treatment of coronary heart disease because of its low price and precise efficacy. Patients should pay attention to the following matters when taking cardiac pain. 1. Take the drug in the early morning to prevent morning angina. Many patients have the experience that the same amount of activity can cause an angina attack in the morning, while the rest of the day is safe and sound. This is related to the physiological increase in blood pressure in the morning along with an accelerated heart rate and other factors that increase myocardial oxygen consumption and trigger myocardial ischemia. Taking cardiac pain before waking up in the morning can effectively relax vascular smooth muscle, reduce myocardial oxygen consumption and prevent myocardial ischemia and angina attack in the morning. 2. Take the drug intermittently to avoid drug resistance. A small number of patients initially use cardiac pain with good results, but the effect of long-term use is becoming less and less obvious, the reason is that the phenomenon of drug resistance has arisen. This part of patients does not advocate the method of uniformly administering the drug every six hours; it is better to take the drug 2-3 times a day, with an interval of up to 10 hours or more in between, so that there is a nitrate-free interval in the plasma to restore the sensitivity to cardiac pain. 3. Gradually increase the dose to eliminate headache. Some patients may have headache symptoms after taking regular doses of cardiac pain. Those who have symptoms but can adhere to the treatment can continue with the regular dose, and generally the headache can disappear after 1-2 weeks of medication. For those who have difficulty in tolerating and cannot adhere to the treatment, a small dose (1/4 tablet, 1/3 tablet) that can be tolerated can be taken and gradually increased to the regular dose step by step, and this process takes 1-2 months or even longer. 4.Sublingual for first aid. Gastroparesis can also be used to treat acute attacks of angina pectoris. Although the onset of action is slightly later than that of nitroglycerin (2-3 minutes), the duration of action is longer. At the same time, the stability of the drug is better than that of nitroglycerin, so it is less likely to expire and can be used as an emergency medicine for angina pectoris. However, it should be noted that when used for first aid, the tablets must be crushed and then sublingually contained in order to take effect quickly.