What to Know About Acetaminophen Dosing in Infants and Children

Medically Reviewed by Mahammad Juber, MD on June 06, 2022
5 min read

Children get sick and injured no matter how well adults protect them. It's natural to want to ease their discomfort when they're not feeling well. Acetaminophen, commonly known by the brand name Tylenol, is a popular medicine for relieving pain and fever in children. Adults should carefully follow the guidelines on how much acetaminophen is safe for children and babies.

Acetaminophen is one of the most common medicines for children in the U.S. When you use the correct dose, it's safe and effective for reducing fevers and pain. Doctors often recommend it for children who are sick, injured, or teething.

Adult-strength acetaminophen comes in pills and gel caps. There are liquid and chewable versions for children and babies who are too young to swallow pills. You can buy many different strengths and formulations of acetaminophen without a prescription.

Acetaminophen is available both on its own and in combination medicines. Cold medicines may contain acetaminophen along with ingredients to address coughing and congestion. These options can include doses of acetaminophen comparable to a regular dose of the stand-alone version.

There are also higher dosages of acetaminophen and stronger combination medications that doctors can prescribe for more severe pain and sickness, such as Tylenol 3, which contains codeine.

The amount of acetaminophen your child needs depends on their age and weight. If your baby is under 12 weeks old, you should not give them acetaminophen unless their doctor has explained acetaminophen infant dosing to you.

Children under 12 years old should not be given more than five doses in a 24-hour period.

Children between 12 weeks and 12 years old should be given a dose based on their weight. The specific weight-based dosing guidelines for 160 mg/5 mL strength liquid acetaminophen are:

  • 6–11 lbs: 1.25 ml or 1/4 tsp
  • 12–17 lbs: 2.5 ml or 1/2 tsp
  • 18–23 lbs: 3.75 ml or 3/4 tsp
  • 24–35 lbs: 5 ml or 1 tsp
  • 36–47 lbs: 7.5 ml or 1.5 tsp
  • 48–59 lbs: 10 ml or 2 tsp
  • 60–71 lbs: 12.5 ml or 2.5 tsp
  • 72–95 lbs: 15 ml or 3 tsp
  • 96 lbs and above: 20 ml or 4 tsp

When you're measuring out a dose of liquid acetaminophen, you should use a dosing syringe or the measuring spoon that comes in the package. Using kitchen utensils or measuring spoons won't be as accurate as a tool meant to measure medicine. You could end up giving your child more medicine than they should take.

Chewable acetaminophen tablets are only appropriate for children who weigh over 24 lbs. The dosing guidelines for 160 mg chewable tablets are:

  • 24–35 lbs: 1 tablet
  • 36–47 lbs: 1.5 tablets
  • 48–59 lbs: 2 tablets
  • 60–71 lbs: 2.5 tablets
  • 72–95 lbs: 3 tablets
  • 96 lbs and above: 4 tablets

You can also find acetaminophen suppositories, which come in doses of 80, 120, 325, and 650 mg. Talk to your doctor about the correct dosing of suppositories.

If your child is taking other medicines, check the ingredients before giving them acetaminophen. If they're taking cold medicine that contains acetaminophen, you shouldn't give them more. Too much of it can be harmful.

Before 2011, acetaminophen came in different strengths for infants and children. The infant formulation was more concentrated than the one for older children. This meant parents didn't need to administer as much liquid per dose to babies, but babies still got the same amount of active acetaminophen.

This changed due to several tragic incidents where adults confused infant acetaminophen with the less concentrated children's formulation. Instead of administering the smaller amount required for the infant concentration, caregivers used the dosing guidelines for older children. As a result, the babies received far more of the active ingredient than they needed. Some of them developed acetaminophen toxicity and needed to be hospitalized.

After 2011, acetaminophen manufacturers agreed to stop making different concentrations for infants and children. All current products use the same concentrations with dosing based on weight. The packages all show the appropriate acetaminophen dosing chart as well.

If you have older acetaminophen products in your home, check the expiration dates. Medications don’t work as well after their expiration dates, so it's wise to replace expired medicines. In the case of acetaminophen, products from before 2011 may have confusing dosing information. Consider buying a more current bottle of medicine for your children's safety.

Taking too much acetaminophen at any age is dangerous. The liver can't process more than the recommended amount, so taking too much can cause it to build up in your body. Eventually, this leads to acetaminophen toxicity.

Children can overdose on acetaminophen and develop toxicity if they accidentally take too much of it. This can happen if they take too many doses or take more than one medication that contains acetaminophen. Sometimes, children take medicines thinking they are candy and make themselves sick. It's important to keep all medications out of children's reach.

Symptoms of acetaminophen toxicity in children include: 

  • Nausea, vomiting, pain in the right side of the abdomen
  • Loss of appetite
  • Fatigue
  • Dark or bloody urine, or reduced amount or frequency of urine
  • Confusion, sleepiness, and loss of consciousness
  • Yellowish hue to skin and eyes (jaundice)
  • Difficulty breathing
  • Blurry vision

If you suspect your child has overdosed on acetaminophen, call 911 for immediate assistance. There are treatments for acetaminophen toxicity depending on the severity and how long it has been since your child overdosed.

Stomach pumping. If your child took too much acetaminophen less than 30 minutes ago, emergency room staff can insert a tube into their stomach to empty it. This procedure is called gastric lavage.

Activated charcoal. If the overdose was less than four hours ago, doctors may give your child activated charcoal. This binds toxins in the digestive tract so your child's body won't absorb them.

N-acetylcysteine (NAC). This medication can prevent liver damage if it's administered within 8 hours of the overdose. It needs to be given through an IV, and your child may need multiple doses over 72 hours.

Without treatment, acetaminophen toxicity is life-threatening. Children can develop kidney failure, pancreatitis, liver damage, or liver failure, which may require a liver transplant. Acetaminophen toxicity can also lead to death.

If you have questions about acetaminophen safety or dosing for children, talk to a doctor. They can help you make sure your child gets the safest and most appropriate treatment.