Non-steroidal anti-inflammatory drugs are very widely used in clinical practice, such drugs from many strokes, coronary heart disease to eat taking aspirin, to the current cold after taking fen-phen, to arthritis taking celecoxib, lexapro, which all belong to non-steroidal drugs, the best drug treatment, need to look at the type of disease. Non-steroidal drugs, also known as antipyretics and analgesics, have two effects, namely antipyretic and analgesic. This class of drugs acts on different receptors, called COX-1 receptors and COX-2 receptors, so they act differently as antipyretics and analgesics. For example, children drink Merlin, which also contains antipyretic and analgesic drugs, aspirin and painkillers, which are also antipyretic and analgesic drugs. The doctor’s tendency in choosing the medication to use is due to the different effects played by antipyretic analgesia. The best antipyretic analgesic should not be understood as the one with the best antipyretic analgesia, but as the one with the least side effects. The antipyretic analgesic with the least side effects requires clarification of the site targeted by the side effects. Antipyretic analgesics are most likely to hurt the stomach. The current three generations of antipyretic analgesics are not likely to hurt the stomach, such as aspirin, fenbendazole, celecoxib, lexapro, indomethacin, which are highly selective drugs, i.e. very low irritation to the stomach. Low-selective drugs, such as Anacin and Depo-Provera, are more irritating to the stomach, and these drugs have been withdrawn from the market and are less used clinically. Whether the patient’s treatment is primarily fever-reducing or analgesic, it is sufficient to clarify the role and therapeutic purpose of the drug when going to prescribe it.