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Acetaminophen

Topic Overview

Acetaminophen (such as Tylenol) reduces fever and relieves pain. It does not reduce inflammation, as do non-steroidal anti-inflammatory drugs (NSAIDs) such as aspirin and ibuprofen, but it is less likely to cause stomach upset and other side effects.

Be sure to follow the non-prescription medicine precautions.

Dosage

  • Adults: The usual dose is 325 mg to 650 mg. Take every 4 to 6 hours, as needed, up to 4 times in a 24-hour period. The maximum dose may vary from 3,000 mg to 4,000 mg but do not take more than 4,000 mg in a 24-hour period. Follow all instructions on the label.
  • Children: Check with your child's doctor or a pharmacist if your child is less than 6 years old or less than 24 kilograms. Give acetaminophen every 4 hours as needed. Do not give more than 5 doses in a 24-hour period. Dosages are based on the child's weight. There are different acetaminophen products for infants and children.
    • Acetaminophen can be found in many forms and comes in different doses.
    • Be safe with medicines. Read and follow all instructions on the label.
    • Do not give your child more than the maximum dose recommended on the label.
    • Be careful when taking over-the-counter cold or flu medicines and acetaminophen (Tylenol) at the same time. Many of these medicines already contain acetaminophen. Too much acetaminophen can be harmful.
    • If you give medicine to your baby, follow your doctor's or pharmacist's advice about what amount to give. Do not use acetaminophen if your child is allergic to it.
    • Acetaminophen and ibuprofen are different products with different dosing recommendations. Talk to your child's doctor or a pharmacist before switching back and forth between doses of acetaminophen and ibuprofen. When you switch between two medicines, there is a chance your child will get too much medicine. Studies have not shown any added benefit from alternating these medicines.
    • Talk to your doctor or a pharmacist before you give medicine to reduce a fever in a baby who is 3 months of age or younger. This is to make sure a young baby's fever is not a sign of a serious illness. The exception is if your baby has just had an immunization. Fevers sometimes occur as a reaction to immunizations. After immunizations, you can give your baby medicine to reduce a fever.

Side effects of acetaminophen are rare if it is taken in correct doses.

  • Nausea and rash are the most common.
  • High doses of acetaminophen can cause liver and kidney damage.

Reasons not to take acetaminophen

Do not take acetaminophen if you:

  • Have liver disease.
  • Drink alcohol heavily (3 or more drinks a day for men and 2 or more drinks a day for women).

Credits

Current as ofJune 3, 2018

Author: Healthwise Staff
Medical Review: William H. Blahd, Jr., MD, FACEP - Emergency Medicine
Kathleen Romito, MD - Family Medicine
Adam Husney, MD - Family Medicine
Martin J. Gabica, MD - Family Medicine
David Messenger, BSc, MD, FRCPC, FCCP - Emergency Medicine, Critical Care Medicine