Acetaminophen

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About This Medicine

Make sure you know about each of the medicines you take. This includes why you take it, how to take it, what you can expect while you're taking it, and any warnings about the medicine.

The information provided here is general. So be sure to read the information that came with your medicine. If you have any questions or concerns, talk to your pharmacist or doctor.

Why is acetaminophen used?

Acetaminophen (such as Tylenol) reduces fever and relieves pain. It doesn't reduce inflammation like nonsteroidal anti-inflammatory drugs (such as aspirin and ibuprofen) do.

What about side effects?

Side effects of acetaminophen (such as Tylenol) are rare if it is taken in the correct doses. Nausea and rash are the most common side effects. High doses of acetaminophen can cause liver and kidney damage.

General information about side effects

All medicines can cause side effects. Many people don't have side effects. And minor side effects sometimes go away after a while.

But sometimes side effects can be a problem or can be serious.

If you're having problems with side effects, talk to your doctor. Your doctor may be able to lower your dose or change to a different medicine.

Always be sure you get specific information on the medicine you're taking. For a full list of side effects, check the information that came with the medicine you're using. If you have questions, talk to your pharmacist or doctor.

What are some cautions about acetaminophen?

Do not take acetaminophen (such as Tylenol) if you have liver disease. And don't take it if you drink alcohol heavily. This means 3 or more drinks a day for men or 2 or more drinks a day for women.

General cautions for all medicines

Allergic reactions.
All medicines can cause a reaction. This can sometimes be an emergency. Before you take any new medicine, tell the doctor or pharmacist about any past allergic reactions you've had.
Drug interactions.
Sometimes one medicine may keep another medicine from working well. Or you may get a side effect you didn't expect. Medicines may also interact with certain foods or drinks, like grapefruit juice and alcohol. Some interactions can be dangerous.
Harm during pregnancy or breastfeeding.
If you are pregnant, trying to get pregnant, or breastfeeding, ask your doctor or pharmacist if all the medicines you take are safe.
Other health problems.
Before taking a medicine, be sure your doctor or pharmacist knows about all your health problems. The medicine for one health problem may affect another health problem.

Always tell your doctor or pharmacist about all the medicines you take. This includes prescription and over-the-counter medicines, vitamins, herbs, and supplements. That information will help prevent serious problems.

Always be sure you get specific information on the medicine you're taking. For a full list of warnings, check the information that came with the medicine you're using. If you have questions, talk to your pharmacist or doctor.

What do you need to know before giving acetaminophen to children?

Here are some things to know about giving acetaminophen to children safely:

  • Be careful when giving your child over-the-counter cold or flu medicines and acetaminophen at the same time. These medicines often contain acetaminophen already. Too much acetaminophen can be harmful.
  • Talk to your doctor or a pharmacist before you give medicine to reduce a fever in a baby 3 months of age or younger. You need to make sure that a young baby's fever isn't a sign of a serious illness.
  • Ibuprofen is another medicine that is used to reduce fever and relieve pain. Acetaminophen and ibuprofen work in different ways and have different dosing recommendations. The goal of using either medicine should be to make your child comfortable rather than to make the fever go away. You will know the medicine is working if your child is acting like themself again or feeling better.
  • Some people try switching back and forth between doses of acetaminophen and ibuprofen. Talk to your child's doctor or a pharmacist before trying it. When you switch between two medicines, there's a chance that your child will get too much medicine.
  • Do not use acetaminophen if your child is allergic to it.
  • Be safe with medicines. Read and follow all instructions on the label.

Credits

Current as of: September 25, 2023

Author: Healthwise Staff
Clinical Review Board
All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.

The Health Encyclopedia contains general health information. Not all treatments or services described are covered benefits for Kaiser Permanente members or offered as services by Kaiser Permanente. For a list of covered benefits, please refer to your Evidence of Coverage or Summary Plan Description. For recommended treatments, please consult with your health care provider.