Aspirin is a centuries-old drug, and in the last century, it was found that small doses of aspirin had an anti-platelet aggregation effect, so it was pushed up to the first-line drugs for the treatment of coronary heart disease. In the clinic, aspirin has a good anti-thrombotic effect and also protects blood vessels, which makes it a popular basic drug for the prevention of cardiovascular and cerebrovascular diseases. From the 1970s to the present, aspirin can reduce myocardial infarction by 1/3, cerebral infarction by 1/3, and cardiovascular and cerebrovascular disease deaths by 1/6, which can be said to be creditable. But at the same time, aspirin also increases the risk of peptic ulcers, the mechanism is that it can lead to a reduction in the synthesis of a substance called prostaglandin, reducing the defense function of the gastric mucosa, causing an increase in the occurrence of gastric ulcers. Also, if you have a combined H. pylori infection, are a chronic smoker and drinker, and are under stress, you are more likely to develop a peptic ulcer or even gastrointestinal bleeding after taking aspirin. In order to better reduce the adverse reactions, in the aspirin tablets on the outside of a layer of antacid coating, this layer of coating can allow aspirin in the stomach acid is not destroyed by the decomposition of the gastric mucosa without contact, such as entering the small intestine in the alkaline environment will be broken down and absorbed, to avoid the damage to the stomach, this kind of aspirin is called enteric-coated aspirin, that is, the current widely used aspirin dosage form. In the primary prevention of coronary heart disease, aspirin has been shown to increase the incidence of bleeding events and is not recommended for primary prevention. The so-called primary prevention, that is to say, there are risk factors for the occurrence of coronary heart disease, such as high blood pressure, obesity, smoking, family history, etc., but these people do not have a definitive diagnosis of coronary heart disease, the use of drugs to prevent the occurrence of coronary heart disease. For people who already have a definite diagnosis of coronary heart disease, or cerebral infarction, etc., it is a secondary preventive treatment, and aspirin is the first-line drug, which is recommended to be taken for a long period of time in order to reduce the occurrence of cardiovascular and cerebrovascular events. Can clopidogrel be used to replace aspirin? The answer is no. Overseas studies have also confirmed that for patients with high-risk ulcers, the combined use of aspirin plus omeprazole is associated with a lower risk of ulcer bleeding than clopidogrel alone. So you can’t arbitrarily stop using aspirin for clopidogrel, the right thing to do should be to add acid-suppressing drugs. When to take aspirin? Before, during or after a meal? For aspirin enteric-coated tablets, they should be taken on an empty stomach. If it is taken with a full meal, because the food lowers the pH of the stomach, it may cause the drug to become a solvent in the stomach, not acting as an enteric-coated tablet and causing damage to the gastric mucosa. In addition if and food together, the stomach digestion of food to make the drug emptying time prolonged, that is, the drug in the stomach stay longer, more likely to occur gastric mucosal damage.