Acetaminophen

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Topic Overview

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

Be sure to follow the nonprescription medicine precautions.

Dosage

Adults: The usual dose is 650 mg. Take every 4 hours, as needed, up to 4 times in a 24-hour period. Do not take more than 4,000 mg in a 24-hour period.
Children: Check with your child's doctor if your child is less than 2 years old or less than 24 pounds. 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.
- Follow all instructions on the label. If you give medicine to your baby, follow your doctor’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. Do not alternate acetaminophen and ibuprofen because of the possible risk of overdose. Studies have not shown any added benefit from alternating these medicines.
- Talk to your doctor 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.

**Acetaminophen dose for your child's weight**
Child's weight in pounds	Child's weight in kilograms	Dose of medicine
Less than 24.0	Less than 11.0	Ask a doctor
24.0-30.0	11.0-13.5	160 mg-200 mg
31.0-36.0	14.0-16.5	200 mg-240 mg
37.0-42.0	16.5-19.0	240 mg-280 mg
43.0-47.0	19.5-21.0	280 mg-320 mg
48.0-55.0	21.5-25.0	320 mg-380 mg
56.0-75.0	25.5-34.0	380 mg-500 mg
76.0-89.0	34.5-40.5	500 mg-600 mg
Over 90.0	Over 40.5	650 mg (adult dose)

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

WebMD Medical Reference from Healthwise

Last Updated: February 28, 2010

This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.