The main ingredient of Anacin is a derivative of aminopyrine, which is also a non-steroidal anti-inflammatory drug. The fever-reducing effect of Anacin can last for 4-6 hours after taking it, but it will not be used clinically as the drug of choice to reduce fever because its side effects are more serious and may lead to hematopoietic dysfunction and even cause aplastic anemia. It is also important to note that this drug is not suitable for long-term use in large quantities. If it is used to reduce fever and the fever is not reduced effectively after one dose or the body temperature rises again, it should be taken again only after an interval of at least 6 hours. If this drug is not effective, you can also use some intravenous antipyretic drugs, such as injectable lysine, or even small doses of dexamethasone and other hormonal drugs, can play a better antipyretic effect.