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Facts you must know about fever reducers for children

When a child’s body temperature exceeds 38 degrees Celsius (100.4 degrees Fahrenheit), parents rush to seek antipyretic drugs. You may have seen your child have a high fever and then quickly relieve it after taking fever-reducing medications. On the other hand, you may have had a difficult experience because antipyretic drugs did not work well for hand, foot and mouth disease, flu, or adenovirus infection. Also, if you have to use antipyretics repeatedly, you might be worried about whether you can use them that often.

Why does my child have a fever?

Body temperature is regulated by nerve cells (located in the anterior hypothalamus or anterior optic junction) and cold and hot receptors (located in the skin and muscles) that are sensitive to temperature changes in the blood. Fever is caused by the following three mechanisms.

  • Pyrogenic source: Fever may be caused by a substance that raises the hypothalamus thermoregulation set-point. Endogenous pyrogens include cytokines such as IL-1, IL-6, TNF-ฮฑ, INF-ฮฒ, INF-ฮณ, and prostaglandin E. Exogenous pyrogens that stimulate the production of these endogenous pyrogens include microorganisms, microbial secretions, drugs, tumors, inflammation, etc.
  • Heat production greater than heat loss: Salicylate poisoning, malignant hyperthermia, etc.
  • Heat loss disorders: Exposure to high-temperature environments or ectoderm dysplasia, etc.

Most acute fever in healthy children is caused by infection. Therefore, it can be said that the fever is part of the immune response of the child’s body to the virus or bacteria that have entered from the outside.

With the exception of heat stroke or status epilepticus caused by febrile seizures, there is no evidence to support concerns that high fever causes brain damage. Therefore, as long as febrile seizures are handled well, there is no need to worry about brain damage.

Does a child with a fever have to take antipyretics?

As fever is an adaptation to infection, some argue that it should be treated only in special cases. However, since the child usually has a hard time with a fever, taking a fever reducer can help relieve the discomfort. In other words, antipyretic drugs are used for the purpose of relieving difficult symptoms due to fever rather than simply to lower the fever.

If healthy children do not have any particular difficulties, it is okay to use antipyretics at temperatures below 39 degrees Celsius. However, if the child’s body temperature is over 39 degrees Celsius, or if the child’s body temperature is over 38 degrees Celsius and the child is struggling, you can try antipyretics. In particular, if the child has a history of febrile convulsions or has a special disease (chronic cardiopulmonary disease, metabolic disease, nervous system disease, etc.), antipyretic drugs must be used.

What should I do if my child’s fever doesn’t go away after taking the antipyretic?

Even if your child takes fever-reducing drugs, their body temperature may not drop below 38 degrees Celsius. However, as mentioned earlier, the primary purpose of administering antipyretics is to relieve uncomfortable symptoms, not to lower fever. Therefore, even if the body temperature stays above 38 degrees Celsius after taking the antipyretic, there is no need to worry too much as long as the child is not struggling.

However, if the child continues to struggle or does not fall well below 39 degrees, cross-administration of other antipyretic drugs may be considered. If the child’s high fever continues and the condition is still bad, do not try to treat it at home and the child must see a doctor.

What should I do if my child has a fever despite taking antibiotics?

If fever due to bacterial infection is suspected, antibiotics may be considered. If the fever continues even after 1 to 2 days after starting antibiotics, the primary antibiotic does not work or it may be a viral infection that does not respond to antibiotics. Therefore, it is necessary to consider replacement of antibiotics or observe the progress while taking symptomatic treatment.

Fever caused by a bacterial disease can be easily removed with appropriate antibiotics, whereas a fever caused by a virus has a characteristic that only resolves after a certain period of time. It is up to the doctor, not the parent, to make decisions about treatment plans, including antibiotic selection and replacement. Therefore, parents just need to follow the doctor’s treatment plan and take care of the child’s condition.

In short, the condition of the child is more important than how long the fever lasts. As long as your child eats and plays well, even if the fever lasts more than 5 days, you can wait and take supportive action. However, if the child is eating poorly and is droopy, even on the day the fever starts, a detailed examination and hospitalization may be considered.

Proper use of antipyretics for children

The two main antipyretics used in children are acetaminophen and ibuprofen. And dexibuprofen, the enantiomer of ibuprofen, is also frequently used. Therefore, dexibuprofen should be viewed as a drug in the same class as ibuprofen.


Acetaminophen can be administered at a dose of 10 to 15 mg/kg per dose at least 4 hours apart. Alternatively, dividing the child’s weight by 3 gives a single dose that is close to the minimum dose. According to the pharmacopoeia, the maximum dose is 20cc according to the body weight. However, it is okay to administer just 10cc to a child weighing 30kg or more.

Acetaminophen may be toxic to the liver. Therefore, it should not be used if there is an abnormality in the liver function test result or hepatobiliary system.


Ibuprofen can be used from 6 months of age, and doses of 5 to 10 mg/kg can be used at least 8 hours apart. Alternatively, dividing the child’s weight by 3 gives a single dose that is close to the minimum dose. As with acetaminophen, it is acceptable to use 10cc for weights over 30kg.

If you are taking ibuprofen at the lowest dose, you should be fine with a minimum interval of 4 hours. However, compared to acetaminophen, it has a longer duration of action, so keep an interval of 8 hours as much as possible.

Ibuprofen can cause gastrointestinal upset, so it is not recommended to take it when your child is on an empty stomach.


Dexibuprofen can be used from 6 months of age. The dose of 5~7mg/kg is taken at intervals of 4~6 hours as needed, and should not exceed 4 times a day. According to the pharmacopoeia, a single dose of up to 25cc can be taken according to the body weight. Simply put, children weighing over 30 kg can take 12 cc.

Like ibuprofen, dexibuprofen can cause gastrointestinal upset, so it is not recommended for children to take it on an empty stomach.

What to Remember About Cross-Dosing Antipyretics

Some doctors recommend not to cross-take between different classes of antipyretics. However, when high fever is not well controlled, there are many cases in which it is inevitable to consider cross-dosing.

From personal experience, it is recommended to give ibuprofen or dexibuprofen 3 times a day if your child has a persistent high fever. If the fever still rises above 38 degrees, additional administration of acetaminophen (minimum interval of 4 hours) is recommended.

However, even in this case, it is not necessary to aim to bring the child’s body temperature down to 38 degrees Celsius or less. This means that even if the child’s body temperature is maintained above 38 degrees Celsius, there is no need to cross-dosing as long as the child is not struggling.

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