Nitroglycerin is the most widely used and effective short-acting anti-anginal drug for patients with acute attacks. It can relieve all kinds of angina pectoris, such as typical angina pectoris induced by exertion, variant angina pectoris caused by coronary artery spasm and unstable angina pectoris, etc. It can take effect after sublingual administration of nitroglycerin for 1 minute. Although nitroglycerin is commonly used, many patients still lack proper understanding of it, mainly in the following ways: 1. Fear of nitroglycerin. Because nitroglycerin has a significant effect on the relief of angina, some people mistakenly believe that nitroglycerin is a “potent drug” and fear that frequent use will cause adverse reactions. In fact, this is a misunderstanding, generally speaking, nitroglycerin does not have serious side effects, although sometimes headaches can occur, but after repeated use that no longer appear. 2. I am afraid to use it again after using it once. Nitroglycerin can take effect after 1 minute of sublingual administration and last for half an hour. 3 minutes later, is it possible to use the drug again if it is not effective? Many people are confused. The correct use of nitroglycerin is limited to 3 times 3 tablets, that is, every 3 minutes when it is not effective, you can take another tablet. If it is not effective after 3 times, it should be considered as severe angina or myocardial infarction, or possibly other diseases with chest pain, and should go to the hospital as soon as possible for treatment. 3. It is considered not to be used for prevention. Nitroglycerin does not necessarily have to be used during an angina attack, but can also be used for prevention under special circumstances. For example, when the spirit suffers from unexpected strong stimulation, or when you are too tired, you can take 1 tablet under the tongue to prevent angina attack. 4. It is believed that vertigo after using the drug is a manifestation of poisoning. Nitroglycerin has certain antihypertensive effect, so individuals can have vertigo, shaking and other hypotensive symptoms after using the drug, which is not poisoning, and can return to normal as long as lying down for a few minutes.