What happens if I give my child too much tylenol?

What the evidence says

Acetaminophen, the medicine in Tylenol, is safe when you give the right amount for your child's weight or age. But giving more than the recommended dose in a 24 hour period can seriously hurt the liver, the organ that cleans toxins from the blood.

The tricky part is that symptoms usually do not show up right away. Early signs can include feeling sick to the stomach, throwing up, not wanting to eat, and pain in the upper belly. Your child might look and act fine for many hours even though damage is already starting inside.

Acetaminophen overdose is actually one of the leading causes of sudden, severe liver failure in Canada, the United States, and other countries. In Canada, there are roughly 4500 hospital visits a year for acetaminophen overdose, and about 6 percent of those patients go on to develop liver problems, including liver failure that can be life threatening. Most accidental overdoses in young children happen because a parent measured or calculated the dose wrong, or gave two different medicines that both contained acetaminophen without realizing it.

The amount that becomes risky is generally described as more than the recommended dose within 24 hours, or giving other products that also contain acetaminophen at the same time, which adds up without anyone noticing. Some research puts the danger zone for a single large dose at over 150 to 200 milligrams per kilogram of body weight, though smaller repeated overdoses over a day or two can also cause harm, especially in a child who is sick, dehydrated, or not eating well.

If you think you gave too much, or your child got into a bottle on their own, call your provincial poison control centre right away, even if your child seems okay. There is an antidote called N-acetylcysteine that works best when given early, before liver damage sets in, so quick action matters.