Fever is one of the common symptoms of many diseases. Excessive fever will cause the body’s functions to be impaired, leading to severe reactions such as cramps, convulsions, coma, etc. Fever for too long will also cause the body to consume more, and insufficient supply of nutrients will lead to other diseases. Fever-reducing drugs can reduce body temperature by regulating the body’s functions, making the body’s surface blood vessels dilate, thus increasing heat dissipation, and at the same time inhibiting chills and reducing the body’s heat production. Clinical use of fever-reducing drugs mostly belong to the antipyretic and analgesic anti-inflammatory drugs (also known as non-steroidal anti-inflammatory drugs), commonly used dosage form oral dosage form, injection, suppository and so on. Classification of commonly used antipyretics Oral antipyretics Oral dosage forms are preferred. The types of drugs include acetylsalicylic acid (aspirin), analgin, acetaminophen (paracetamol), ibuprofen and so on. Oral dosage forms include drops, dispersible tablets, dry suspension, extended and controlled release tablets, suspension, capsules, chewable tablets, granules, oral solution, orally disintegrating tablets, effervescent granules, effervescent tablets, and others. Aspirin is inexpensive, easy to obtain and highly effective. However, since the United States in 1984 disclosed that Rachel’s syndrome and aspirin-related, has been withdrawn from the legislation of aspirin as a pediatric preparation. WHO also does not advocate giving acute respiratory tract infections in children with fever application of aspirin. The WHO also does not advocate the use of aspirin in children with acute respiratory infections. The treatment protocols for infectious atypical pneumonia and highly pathogenic avian influenza in China also caution against the use of aspirin in febrile children. Anacin was first used as antipyretic and analgesic in the 1920’s. In the 1970’s there were reports of fatal agranulocytosis caused by this product. It is now rarely used in China. The two preferred oral antipyretics are acetaminophen and ibuprofen. Acetaminophen can be used for children over 3 months of age and adults. However, because acetaminophen has been reported to cause hemolysis, ibuprofen may be used to reduce fever in patients at risk for hemolysis. Ibuprofen may also be considered for patients whose fever is not reduced with acetaminophen. Injectables For patients who are unconscious, poor feeders, and unable to take medications orally. Types of medications include acetaminophen injection, ampicillin injection, and cotrimoxazole barbiturate injection. These drugs act quickly, body temperature drops rapidly, and patients sweat more, so be careful to get enough fluids when using them. And because the patient’s body temperature drops too quickly, there are many adverse reactions, the current clinical has been rarely used. Suppositories Suppositories can also be considered for patients who are unconscious, poorly fed, and unable to take medication orally, such as indomethacin suppositories, aspirin suppositories, pediatric ibuprofen suppositories, dextrose ibuprofen suppositories, and so on. The absorption of suppositories does not pass through the liver, but directly from the intestinal mucosa into the bloodstream, does not stimulate the gastrointestinal tract, and has a faster onset of action than oral administration. However, in terms of absorption rate, suppositories need to be absorbed through the mucosa, and the absorption rate is lower than that of oral administration. Therefore, the general oral maximum dose is 15mg/kg per dose, with suppositories, the dose should be correspondingly larger, each time the maximum dose can be used to 20mg/kg. How to use antipyretics? The principle of using antipyretics is to use the oral form. They should be used once every 6 hours, up to 4 times a day, and not more than 3 days in a row. Monitor body temperature before and after the use of antipyretics. Dosage of commonly used oral antipyretics 1. Acetaminophen 500 mg per dose for children and adults 12 years of age and older; 250 mg per dose for children 6-12 years of age; if fever or pain persists, the medication may be given at 4-6 hour intervals, and should not be given more than 4 times in a 24-hour period; for children less than 12 years of age, the medication should be given for each body weight. Children under 12 years of age should be given per body weight. Extended-release dosage forms should be given every 8 hours, not more than 3 times in 24 hours. 2.Ibuprofen Children over 12 years of age and adults 200 mg at a time, if the pain or fever persists, may be repeated at intervals of 4-6 hours, not to exceed 4 times in 24 hours Children under 12 years of age are administered per body weight. Children under 12 years of age should be given per body weight. Extended-release dosage forms should be given once in the morning and once in the evening. Dosage of other antipyretics (1) Acetaminophen injection: intramuscular injection of 0.15-0.25 g. This product should not be used for a long time, and the course of antipyretic treatment usually does not exceed 3 days. (2)Aminophenobarbital injection: intramuscular injection, 2 ml at a time, children under one year of age and newborns are prohibited due to insufficient development of liver and kidney function. (3)Compound aminobarbital injection: Intramuscular injection. Adults 2 ml at a time, or as directed by the doctor. Under supervision, the extreme dosage is 6 ml a day. under 2 years of age: 0.5-1 ml/dose; 2-5 years of age 1-2 ml/dose; more than 5 years of age 2 ml/dose. It should be noted that this product should not be used continuously. (4) Indomethacin suppository: rectal administration. Gently inserted into the anus at about 2 cm, one pessary at a time, once a day, the daily dose should not exceed 2 pessaries. (5)Pediatric ibuprofen suppositories: Rectal administration: 1-3 years old children, one capsule at a time (inserted into the anus at a distance of about 2 cm), if the symptoms are not relieved, repeat the procedure at intervals of 4-6 hours, and do not exceed 4 suppositories in 24 hours.100 mg suppositories per capsule are recommended for children over 3 years old. (6) Aspirin suppositories: Rectal administration: children and adults 12 years of age and older, 1 suppository to be inserted into the anus at a distance of approximately 2 cm. If fever or pain persists, repeat at intervals of 4-6 hours, not more than 4 times in 24 hours. Precautions for use of antipyretics (1) Acetaminophen is safe to use in reasonable doses, but exceeding the maximum dose can cause liver damage. Commonly used combination cold remedies often contain “acetaminophen” as an ingredient, such as Amphenol Pseudoana Min Capsules and White Plus Black Cold Tablets. If you use a single ingredient of acetaminophen to reduce fever, and at the same time take the above compounded cold medicines, it is easy to overdose on acetaminophen due to repeated use of the medication. Therefore, it is important to double-check the composition of the medication before use, and to avoid taking medicines that contain the same active ingredient in combination with each other. (2) Ibuprofen has a strong antipyretic effect, and the process of reducing fever can cause the body to sweat a lot, so Ibuprofen is not suitable for patients with fever who have symptoms of dehydration. At the same time, ibuprofen is excreted through the kidneys, and should be used with caution in patients with poor kidney function. Adverse effects of ibuprofen may induce asthma and should be used with caution in children with asthma. (3) If high fever persists, consider alternating acetaminophen and ibuprofen, with a minimum dosing interval of 4 hours for acetaminophen. When the fever does not go down two hours after the maximum dose of acetaminophen has been used, ibuprofen can be used alternatively, with a minimum time interval of two hours between the two drugs. When alternating, the maximum number of times each drug can be used per day remains the same. (4) The use of antipyretics only relieves the fever as a symptom, and does not treat the infection that causes the fever itself, which is “treating the symptoms but not the cause”. The cause of fever needs to be identified. Antipyretics in the conventional sense only reduce the temperature and do not treat the pathogen causing the disease. For example, when high fever is caused by bacterial pneumonia, antibiotics are needed to control the bacteria first, so as to achieve the effect of completely reducing the inflammation and cooling down the temperature.