Antipyretics are drugs that, when applied, cause a drop in body temperature. The most commonly used in clinical practice are non-steroidal anti-inflammatory drugs, the most commonly used of which is ibuprofen, and acetaminophen is also frequently applied. Since it is the most commonly applied drug, it is generally because the effect of reducing fever is relatively good, and the possibility of side effects is relatively small. Therefore, it is important to choose a drug that has more clinical applications, such as ibuprofen or acetaminophen, to reduce fever. However, these drugs may also cause some adverse reactions, most notably damage to the gastrointestinal system, such as stomach pain or aggravation of existing peptic ulcers. Ibuprofen or acetaminophen are NSAIDs, so such side effects do exist, but they may be slightly less likely to occur than other NSAIDs.