After continuous popularization, netizens now know that there are only two kinds of fever-reducing drugs widely used in the world, namely “acetaminophen” and “ibuprofen” recommended by the World Health Organization, and acetaminophen has been used for a long time clinically and has high safety as the Acetaminophen is the preferred antipyretic drug because of its long clinical use and high safety. Because acetaminophen is available in oral and suppository forms, I am often asked questions such as, “Why is there an oral form of acetaminophen when there is a suppository for rectal administration? Aren’t suppositories supposed to have fewer side effects than oral ones, and aren’t they supposed to be non-hepatic?” With this question in mind, let’s compare the differences in absorption and metabolism between oral and suppository doses. The main site of absorption of oral acetaminophen is in the small intestine, and before entering the systemic circulation, it will first pass through the portal vein to the liver (refer to the picture). The site of absorption of the suppository is in the rectum, and it enters the systemic circulation by two routes: if the site of insertion is deep (about 6 cm from the anal opening), the drug also reaches the liver via the portal vein before entering the systemic circulation, and most of it is inactivated, just like oral drugs. If the plugging site is shallow (about 2cm from the anal opening), the drug mainly enters the systemic blood circulation through the inferior rectal vein and anal vein → internal iliac vein → inferior vena cava, without passing through the portal vein, and without passing through the liver. The above mentioned is only the absorption stage. After absorbed into the systemic blood circulation, the drug will reach the site of action to exert its effect, and then it has to be metabolized and inactivated by the liver through the blood circulation, which is the detoxification of the liver we often talk about. Therefore, excessive dosage or overuse of suppositories can also harm the liver. Therefore, in terms of safety, the difference between suppositories and oral administration is not great, the side effects are similar, and it is safe to use them strictly according to the recommended dosage, while overdose can harm the liver. In the clinical treatment of fever in children, oral acetaminophen is often the preferred dosage form, and suppositories are used as an alternative only when children cannot take oral medications due to nausea, vomiting, or crying. This is because the use of fever reducers in children often requires precise calculation of the dose based on body weight, and the oral solution form allows for precise dosing, while suppositories are often given at a fixed dose of 125mg or 150mg, which is not as easy to administer precisely for individual body weight. I have seen many mothers from the Internet to amass foreign fever suppositories, in fact, acetaminophen suppositories are produced in China and can be bought in pharmacies, so there is no need to amass. I always advocate that medicines should be bought in China as much as possible, because you need to read the instructions from beginning to end before using the medicine, which is also responsible for your child, while the instructions of the medicine from the sea are written in the local language, so it is easy to misuse it because you can’t understand the instructions. A few tips for using antipyretic drugs: 1. Antipyretic drugs should only be considered when the child’s body temperature is greater than 38.5 degrees, but not below 38.5 degrees. For example, if a child has a fever of 39 degrees this morning and is given the medicine once, he does not have a fever again until the next morning, in this case there is no need to take the medicine every 4-6 hours as stated in the instructions in order to prevent recurrent fever. 2. While using antipyretics, make sure that the child has an adequate amount of fluid intake. 3. Give antipyretics according to the weight of the child, not according to age, because the weight of children of the same age varies greatly. Do not wake up a sleeping child to take the medicine, sleep is more important than taking fever medicine. 5. Do not combine fever medicine with cough and cold medicine, because these medicines often contain the same antipyretic ingredients, which can inadvertently lead to overdose poisoning in children. 6. Do not use utensils such as spoons to estimate the amount of medicine you need to take, you should measure the medicine accurately with a medicine dispenser or a syringe with a scale. 7. Be sure to put the fever-reducing medicine out of reach of children. Strawberry or orange flavored fever reducers are also attractive to children who are sick, and there are often clinical examples of children drinking the medicine as a drink and getting poisoned.