Beware of an Accidental Acetaminophen Overdose

How to avoid taking too much acetaminophen and what happens if you do

When you want relief from an ache, pain, fever or cold, you might head to the medicine cabinet for acetaminophen, often called by its brand name, Tylenol^®. It can be a quick over-the-counter way to feel better.

“Even though it’s commonly used, that doesn’t mean it’s safe for everyone. It can be used excessively,” says Jennifer Heikkinen, PharmD, a Geisinger ambulatory care pharmacist. “You can overdose on acetaminophen, especially if you’re taking other medications where it might be easy to miss.”

Know how to find your total dose, and signs you need to seek help for taking too much.

What is acetaminophen?

On its own, Tylenol is a staple of medicine cabinets everywhere. But you’ll find acetaminophen in other medicine, too, like over-the-counter cold and flu remedies.

It comes in a few forms, including:

Tablets
Capsules
Liquid
Suppositories

This common pain reliever may also be labeled as:

APAP
Acetaminoph
Acetaminop
Acetamin
Acetam
Paracetamol (in Europe, United Kingdom, Australia and India)
Tylenol

What is an acetaminophen overdose?

"An acetaminophen overdose can occur if you've taken more than is safe in a 24-hour period," says Dr. Heikkinen.

Although acetaminophen is a safe, effective medicine, too much of it can lead to acetaminophen poisoning, which can cause liver damage or even liver failure. The liver is the primary organ that processes acetaminophen — and taking too much is the most common cause for liver failure in the United States.

How much acetaminophen can an adult take in a day?

"In general, the most adults can safely take is up to 4,000 milligrams (or 4 grams) of acetaminophen in a 24-hour period, unless directed otherwise by a healthcare professional,” says Dr. Heikkinen.

To help keep track of how much you’re taking, set a reminder on your phone or on your voice assistant.

Avoid acetaminophen overdose in children

“Children process medications differently than adults. The maximum dose a child should take varies by their weight and age,” says Dr. Heikkinen. To protect children from acetaminophen overdose:

Follow the manufacturer’s instructions for your child’s age and weight.
Use the syringe or dosing cup provided with the medicine to measure the dose.
Avoid giving a child more than 1 medication containing acetaminophen.
Space doses apart as directed on the labeling.

Contact a healthcare provider or poison control immediately if you suspect overdose.

Signs of an acetaminophen overdose

About 50% of acetaminophen overdoses in the U.S. are accidental. What happens when you take too much acetaminophen? You can damage your liver and cause serious illness. Look for these symptoms in children or adults:

Abdominal pain
Diarrhea
Jaundice (yellowing of the skin and eyes)
Loss of appetite
Mood changes
Nausea or vomiting
Seizures
Loss of consciousness

However, says Geisinger pharmacy resident Lacey Blauser, PharmD, “some people may not have any symptoms or only very mild ones.”

Symptoms can start gradually and take up to 12 hours to come on. If you suspect an overdose, contact your healthcare provider or your local poison control center. They can walk you through next steps.

Watch what you take

Although taking too much acetaminophen — or taking it too often — is easy to do, following these tips can help you avoid an overdose.

1. Read the labels

"Medicines that contain acetaminophen list it under the active ingredients section of the packaging," Dr. Blauser says.

Also check the label carefully to see whether the medicine contains regular acetaminophen or the extended-release form.

Another tip: Don’t just review medicine that’s specifically for pain relief. Look over the labels on your supplements and sleep and cold medicine, as well.

2. Take the correct dose

While looking at the label, check to make sure you’re taking the correct dose, especially when you take extended-release acetaminophen.

“Never take more than the label says to take, and wait the right amount of time between doses,” Dr. Heikkinen says. That means if it says to take some every 4 to 6 hours, wait the full 6 hours whenever possible.

3. Don't take more than one type of acetaminophen at a time

Since many types of medicine contain this painkiller, make sure the total dose you take doesn't exceed 4,000 milligrams or 4 grams in 1 day, unless directed otherwise by a healthcare professional.

"You should be cautious when taking medicines together that contain acetaminophen — the combined amount may be too much," says Dr. Heikkinen. Plus, the acetaminophen in a single type of medicine may address the aches and pains you may be taking multiple types of medicine for.

4. Don't take it for too many days in a row

"Don't take acetaminophen for more than 10 days to treat pain, and don't take it for more than 3 days for a fever," says Dr. Heikkinen.

Pain or fever that lasts longer should be evaluated by a healthcare professional.

What medicines could contain acetaminophen

Many people who overdose on acetaminophen accidentally take multiple medications that contain it. While all products containing acetaminophen are required to be clearly labeled, it can be easy to miss it in a new medication or forgotten in one you take all the time. Check for it in:

Cold and cough medicines

Cough and cold medicines that treat a variety of symptoms often contain acetaminophen as 1 of several ingredients to treat fever and achiness.

Headache reliever

Migraine and extra-strength headache medications often contain acetaminophen and caffeine or aspirin.

Menstrual or premenstrual pain medications

Some versions of Midol^® and Pamprin^® contain acetaminophen, so be cautious about how much you take.

Prescription pain reliever

For acute pain or after surgery, your doctor might prescribe a pain reliever that contains acetaminophen. Check with your doctor before you take any over-the-counter pills in addition to your prescription medication.

Sleep aids

Over-the-counter medications for sleep and pain often contain acetaminophen and another ingredient to help you sleep.

What do I do if I took too much acetaminophen?

If you take too much in 1 day or have symptoms of overdose, it’s a medical emergency. Get to the hospital right away. They can evaluate the need for a medication that counteracts the acetaminophen and may prevent liver failure when given within 8 hours.

Always ask when you’re unsure

Not sure about how much acetaminophen is in your pain reliever or a new medication? Ask your healthcare provider or pharmacist. They can help you understand how much you’re taking so you can avoid toxicity. Tell your doctor about any over-the-counter drugs or supplements you take regularly.