Useful information

How to choose an antipyretic analgesic after corona vaccine


Vaccination against new coronavirus infections is underway, but it has been reported that side reactions such as headaches and fever are occurring at a considerable rate.
Some of you may have heard these reports and stocked up on antipyretic analgesics in advance. Recently, I’ve heard the news that some antipyretic analgesics are running out of
stock at pharmacies nationwide.
This time, I will tell you about side reactions after corona vaccination and antipyretic analgesics.

What is the rate of side reactions after having the corona vaccine?

You may be curious about how often side reactions occur after vaccination against the new coronavirus infection.
According to the results of a survey released by the Ministry of Health, Labor and Welfare on June 23, about 40% of the approximately 20,000 medical workers who had been vaccinated with Pfizer’s corona vaccine in advance were observed to have had a temperature of 37.5 degrees or higher after the second vaccination.

Similarly, headaches are more common after the second vaccination than the first, and are reported in more than half of all cases.

What is an antipyretic analgesic?

The Ministry of Health, Labor and Welfare has posted on the site “New Corona Vaccine Q &
A” ( about how to deal with these side reactions.
“Can I take over-the-counter anti-fever and analgesic drugs for pain?” is explained in “Q”.
The answer to this “Q” is, “It is permitted to use over-the-counter antipyretic analgesics for fever and pain after receiving the vaccine,” and then the specific types of antipyretic analgesic are also introduced.
Here, let’s briefly explain what an antipyretic analgesic is in the first place.
It’s a so-called “pain reliever” or “heat relief”. “Anti-fever analgesics” are used to relieve headaches, toothaches, low back pain, menstrual pain, neuralgia, etc. (pain relievers), and to relieve fever (heat relief).

What kinds of antipyretic analgesic can be used after the corona vaccine?

If you go to a pharmacy or drugstore, you can find various kinds of antipyretic analgesics.
What antipyretic analgesics can be used for fever and pain after vaccination with the corona vaccine? In the “New Corona Vaccine Q & A” mentioned earlier, we explained as follows.
“The types of antipyretic analgesics on the market include acetaminophen and non-steroidal anti-inflammatory drugs (ibuprofen and loxoprofen), which can be used for fever and pain
after vaccination.”
In other words, it specifically mentions “acetaminophen” and “non-steroidal anti-inflammatory drugs (NSAIDs)”.
“Acetaminophen” is one of the antipyretic analgesics that acts on the body temperature center of the central nervous system to release heat to the outside of the body. It has relatively mild side effects and is also included in over-the-counter cold remedies.
“Non-steroidal anti-inflammatory drugs” are also among the antipyretic analgesics, and exhibit antipyretic, analgesic and anti-inflammatory effects by suppressing the production of
substances that cause pain and inflammation (prostaglandin). “Ibuprofen” and “loxoprofen” are well-known non-steroidal anti-inflammatory drugs.

Why acetaminophen is scarce

By the way, many of you may have heard the news that antipyretic analgesics containing acetaminophen are running out of stock in stores.
Why do more people buy acetaminophen in case of a side reaction to the corona vaccine?
This is because from the beginning of the epidemic of the new coronavirus infection, there was a belief that non-steroidal anti-inflammatory drugs (NSAIDs) might exacerbate the
symptoms of the new corona. Also, for other infectious diseases such as influenza, acetaminophen, which has fewer side effects than NSAIDs, is often recommended.
However, as mentioned above, the Ministry of Health, Labor and Welfare says that both acetaminophen and NSAIDs can be taken for fever and pain after this corona vaccine.
Supporting this is the fact that the Centers for Disease Control and Prevention (CDC) may use NSAIDs as well as acetaminophen, and that many people in large-scale clinical trials conducted by Pfizer had reduced fever by including NSAIDs. It was observed that they were taking painkillers but had no serious side effects.

People who need attention

However, some people need to be careful when using antipyretic analgesics for fever and pain after vaccination.
The Ministry of Health, Labor and Welfare’s “New Corona Vaccine Q & A” advises to consult your doctor or pharmacist in the following cases.
・ If you are taking other medicines, or if you are pregnant, breastfeeding, elderly, or undergoing treatment for illnesses such as gastric / duodenal ulcer or renal dysfunction →
The medicines you can take may be limited.
・ If you have had allergic symptoms or asthma due to medications, etc.
・ If the symptoms are severe, such as severe pain or high fever, or if the symptoms continue
for a long time.
・ If you have symptoms that are not typical after vaccination
If you are uncertain, please consult your doctor or your pharmacist at the pharmacy.
◎ Reference
Ministry of Health, Labor and Welfare “Health Survey after Inoculation of New Corona Vaccine”
Ministry of Health, Labor and Welfare “New Corona Vaccine Q & A”
――Q: Can I take over-the-counter antipyretic analgesics for fever and pain after receiving the vaccine?
CDC “Possible Side Effects After Getting a COVID-19 Vaccine”