Acetaminophen-What every caregiver should know.

Author: Mark Parkinson RPh:  President  AFC CE

Credit Hours 1- Approximate time required: 60 min. 

Educational Goal:

Guide the caregiver in the safe use of the drug Acetaminophen.

Educational Objectives:

  1. Show how prevalent acetaminophen use is in America.
  2. Tell how acetaminophen works and why it so safe to use.
  3. Explain about acetaminophen toxicity and how it can occurs
  4. List caregiver concerns about acetaminophen use.
  5. Tell about the antidote of acetaminophen poisoning and provide helpful hints on its use in the home setting.


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 The information presented in this activity is not meant to serve as a guideline for patient management. All procedures, medications, or other courses of diagnosis or treatment discussed or suggested in this article should not be used by care providers without evaluation of their patients’ Doctor. Some conditions and possible contraindications may be of concern. All applicable manufacturers’ product information should be reviewed before use. The author and publisher of this continuing education program have made all reasonable efforts to ensure that all information contained herein is accurate in accordance with the latest available scientific knowledge at the time of acceptance for publication. Nutritional products discussed are not intended for the diagnosis, treatment, cure, or prevention of any disease.


Acetaminophen-What every caregiver should know.


Acetaminophen is an analgesic (pain killer) and antipyretic (fever reducer) medication and the most common drug ingredient in America today. It was first used clinically in 1893 and became commercially available in the United States in 1950 when the McNeil Co. first produced Tylenol. Of all medications caregivers must manage, acetaminophen is the one they are most likely to come across most often.

But there are rumors that acetaminophen is actually bad for you. Someone heard somewhere of people loosing there livers to Tylenol or dying from an overdose? Is acetaminophen really safe? Should caregivers listen to the rumors and be concerned? The answer is, yes, it is safe, and, yes, people have sustained liver damage, and, yes, caregivers should be concerned about its use. “What, Huh… ”? A bit confused? That’s OK. This article will tell you what caregivers need to know about acetaminophen.

How It Works

Tylenol, Panadol, Feverall, and Goody’s powders are all brand names for acetaminophen. Acetaminophen works by disrupting certain chemical processes that the body uses to produce pain and fever. Think of it as removing one of the first dominos in a domino chain. Without that first one, the rest can’t fall and activate the reactions. Without the reactions, the pain signal doesn’t reach the brain and the fever center of the body doesn’t get activated.

(An important fact: Acetaminophen doesn’t work on inflammation and swelling like other pain killers do. For example, aspirin or ibuprofen.)

The Side-Effect Profile

This medication works mainly in the central nervous system, with only minor action in the rest of the body.  It is easily broken down by the liver, and its metabolites (what is left over after it’s broken up) are easily removed through our bodily wastes. Acetaminophen or its metabolites does not significantly interact with other functions or parts of the body. There is one minor metabolite that can be toxic to the liver. Only about 4-5 percent of the medication is turned into this toxin, and the body has a liver enzyme that can take care of it. Because so few other reactions occur with acetaminophen, it causes very few side-effects. There are other pain and fever medications that are more effective, but none of them have fewer side-effects to worry about.

So, yes, this drug is safe. It is so safe that drug manufacturers have put it in just about everything. Doctors hand it out without too much concern. And consumers buy and use it almost as a cure-all remedy without any worries. Can you see a pattern here? More on that later.


Americans love their Tylenol. You can buy it for yourself or your children in more  than 600 over-the-counter (OTC) and prescription drugs that contain acetaminophen. You will probably recognize the acetaminophen abbreviation- APAP in most narcotic and opiate pain killers. For example, Vicodin or Lortab is hydrocodone/APAP 5/500 and has 500 mg of APAP. Percocet, oxycode/APAP 5/325 has 325 mg of APAP.  Close to 25 billion doses (that’s Billion with a capital B) are sold in the United States every year. As part of that total, 200 million APAP-containing prescriptions are written by various prescribers. Everyone prescribes it - dentists, nurse practitioners, podiatrists, and to ER and family doctors.

Here are some OTC products that contain acetaminophen.

Cold and Flu


Sleep and Pain




Tylenol PM


Alka-Seltzer Plus Liquid Gels


Unisom with pain relief





Sominex Pain Relief

Store brands


Goodys powders

Store brands







Saint Joseph Aspirin-Free 












Store brands



Formula 44
































Not all products of a brand may contain acetaminophen


Although it is a safe drug, there are limits to how much acetaminophen any patient should take. Too much of anything can be bad.  Often, the difference between a remedy and a poison is how much you consume.  According to the FDA, without doctor supervision, the most acetaminophen a person should consume in a day is 4,000 mg. That amount decreases if the patient has liver damage, is very small, or is a child under the age of 6. How many pills is that? Let’s do some math. Extra-Strength Tylenol contains 500 milligrams, 500 divided into 4,000 equals eight pills a day. If you take two pills at a time, that’s only four doses a day.

If that gets your caregiving attention, it should. Don’t worry too much, though. Most directions for use are well within the safety guidelines. So this medication is safe when used correctly, BUT with so many products containing acetaminophen coupled with an unconcerned consumer and the various prescribers all writing APAP-containing prescriptions, it is very easy for patients to take overlapping doses without even realizing it. It is a pattern that can lead to overdosing and a very Unsafe outcome. You saw that pattern coming, didn’t you?


Poisoning and Liver Damage

For every dose of acetaminophen, 4-5 percent of it is broken down in the liver into the highly reactive and very toxic N-acetyl-p-benzoquinone imine (NAPQI).  The liver can protect itself from NAPQI with its own highly reactive enzymes, chiefly CYP2E1. The names aren’t important to remember. It’s how much of them are in the liver at any given time that’s critical to your caregiving efforts and your residents’ health. The liver only produces so much CYP2E1. When it’s used up or is not replaced quickly enough, NAPQI starts to build up and have toxic effect in the liver causing damage. The liver can repair itself but there are limits to that too. Once a certain point is crossed, the patient turns into a poisoning victim. If the liver is lost then the patient can die.

In an eight-year period there was reported to the AAPCC National Poison Data System; 616,395 acetaminophen poisoning, 13,016 became life-threatening and 1,217 people died. On a year to year basis Acetaminophen poisoning accounts for 31 percent of all fatalities reported to the National Poison Data System. So the rumors are true. People have lost their lives from taking too much acetaminophen.

I hope you can now start to understand why Tylenol is safe but its use should be a matter of concern to caregivers.  Because of the toxic effects of too much acetaminophen, good caring should require the medication dispenser to keep an eye open to potentially harmful amounts consumed. In my opinion, it is all too easy for safety thresholds to be exceeded in care homes. Caregivers should be mindful of the following conditions that can lead to dangerously high doses being given to their residents. 

Problem: Multiple drugs containing acetaminophen.

With acetaminophen in so many products, caregivers should be aware of all the different sources of the drug. Review each client’s drug list and specifically search for the ingredient. Read the ingredients of all OTC products. In prescriptions, be aware of the generic name of the medication. That is where you’ll find acetaminophen hiding. Acetaminophen is a long word, so it is often shortened. Look for the following abbreviations: APAP, AC, Acetaminoph, Acetaminop, Acetamin, Acetam, Acet or MPAP. Products that commonly contain acetaminophen include cold/ flu products, allergy medications, fever reducers, narcotics and sleeping aids, and various other combination products that contain pain relievers.

Problem: PRN dosing and the casual attitude of the consumer regarding the safety of the drug.

After you have found all sources, do a quick total of all the potential doses that could be taken in a 24 hour period. If the 4,000 mg dose could be exceeded, put safety measures in place. I know residents can be quite demanding regarding pain products. They are not thinking of their livers. They are thinking about their pain. Sometimes it will be required for you to say “no. It will help if you remind your residents that you’re protecting them from potential poisoning.  The word poisoning should get their attention. Another option is to (with a physician’s approval) alternate doses of another pain reliever like ibuprofen.

Communicate effectively at shift changes. That is where communication about the amounts of PRN meds being taken can break down. Everyone must look at the MARs record, especially the PRN log, BEFORE giving the next dose – especially after a shift change. Another suggestion is to put a note on the MAR PRN log, capping the amount of pills to be taken (e.g. no more than eight per day). That way everyone has an easy way to stay in the safe zone. 

Uneducated family members and guests who take the resident away from the home should be informed and counseled about giving meds to the client. Can you see a well-meaning friend or multiple family members all pulling out a spare Tylenol every time their loved one complains about their aches and pains? 

Problem: Multiple prescribers

Let’s face it, prescribers are busy people, and they are human. Not everyone will look at the med list you provide to them. (You are sending a current med list to every medical visit, right?) Not everyone will be looking at the total acetaminophen consumed by the patient. Not all prescribers talk to one another.

This is where you come in. Part of your caregiving role is to coordinate among all members of the caregiving team. I know you are not allowed to make clinical decisions or change quantities, but you can ask questions and make observations. For example, if a dentist has given a pain drug that pushes the safety envelope, call them and point it out. Very few prescribers will react negatively to that kind of call, especially if you do it with respect. In the end, they will be grateful to you for pointing out the potential disaster. It keeps them from being sued. No one wants that.

Problem: You can’t always control what the resident does

As a care provider, you do your best to protect your residents, but… You’re a caregiver, not a jailor or a dictator. Residents have rights. If they really want to, they can do stupid things. We also live in a busy world and mistakes happen. Sometime bad things happen even if you do everything right. Part of your job is to be prepared IF things go wrong. Have a plan in place. Always count the number of acetaminophen doses that are taken and be aware of the signs of overdose. Know who to call and where to take the overdose victim. Overdose treatment warning: Never make a resident throw up (it doesn’t help in Tylenol poisoning), and never use laxative measures (they don’t help either).

depressed elderly woman

Signs and symptoms of acetaminophen poisoning

There are two types of acetaminophen poisoning: acute and chronic. If a person takes more than 7,500 mg in a 24-hour period or a child under the age of 6 takes more than 68 mg per pound of weight, it’s a sure bet that the liver’s defenses are going to be overwhelmed. Poisoning symptoms won’t happen right away, but liver damage will soon follow. By the time symptoms start to appear, the resident might already be in the danger zone. If you suspect an acute overdose, send the patient to the hospital with or without poisoning symptoms. For adults who are very small, very frail, or have preexisting liver damage, use overdose value of 68 mg per pound, just to be safe.

With chronic poisoning, the safety margin has been exceeded far too often and the liver is already damaged to the point of malfunction. Regardless of acute or chronic poisoning, be watchful for the following signs and get help.

  • nausea
  • vomiting
  • loss of appetite
  • sweating
  • extreme tiredness
  • unusual bleeding or bruising
  • pain in the upper right part of the stomach
  • yellowing of the skin or eyes
  • flu-like symptoms

I think it would be helpful for you to know that often acetaminophen-poisoning victims don’t show symptoms in the first few hours. Stomach problems are often the first indication. Those symptoms may go away for a time, but return as abdominal pain and upper-right quadrant tenderness (that’s where the majority of the liver is). If you see this pattern, call 9-1-1 right away.

The antidote

Fortunately there is hope for the acetaminophen poisoning victim. The liver has a tremendous capacity to renew itself, so if help comes in time, the patient can recover. The antidote for the NAPQI toxin is Acetylcysteine. It is a liquid that can be administered thru an IV or swallowed in a drink. Acetylcysteine is very nasty-tasting, and the victim will have to take a lot of it (17 doses). If, on the very rare occasion you are asked to give it at your home, ask for permission the put it in a cola drink. It won’t affect the medication, and it will make it easier to get the whole antidote taken. If the patient throws up a dose of the antidote, call the doctor right away for more instructions.

 Just to be complete in this section about poisoning, you should be aware of the national Poison Help telephone number 1-800-222-1222. I’d tape that number inside your MARS binder if I were you.

Missed doses

The question of missed doses of a regularly scheduled acetaminophen regimen comes up from time to time. I recommend taking the missed dose as soon as you remember it. But if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one. The medicine doesn’t work that way.

One more thing

All acetaminophen products except time-release versions can be crushed and given as a powder. It’s OK to put the powder in a feeding tube, but it’s easier to get the adult strength liquid Tylenol OTC product.


I hope this article has told you all you need to know about handling acetaminophen in all its forms. It works on the pain and fever domino chain to stop the body from experiencing them. We have showed you that it is the most prevalent medication in America. We have warned you of the different ways that an accidental overdose could occur. We have explained how an overdose can lead to liver damage and death. We have also provided a description of the signs and symptoms so you can watch for them. We have even told you a few medication dispensing tricks. It is our hope that you now are a better care provider and can give better and safer care to your residents.

As always, good luck in your caregiving.

Mark Parkinson, RPh



1. Edward P. Krenzelok, PharmD, FAACT, DABAT. Navigating Acetaminophen Overdose: What Every Pharmacist Should Know. Powerpak CE Universal Activity Number – 0809-9999-13-307-H01-P. Aug. 1, 2014

2. Paracetamol. Wikipedia The Free Encyclopedia Feb. 22, 2015.

3. Common Medicines with Acetaminophen. Know Your Acetaminophen Awareness Coalition.

4. Gerald J. Dal Pan, MD, MHS. Acetaminophen: Background and Overview. Drug Safety and Risk Management Advisory Committee, Food and Drug Administration. June 29. 2009

5. Prescott LF. Paracetamol: past, present, and future. American Journal of Therapeutic, pg 143-7, Mar. 7, 2000 Pub

6. Acetaminophen.       

7. Acetaminophen. Medline Plus, National Institute of Health.

8. Krenzelok EP, Green JL, Dart R. Acetaminophen (Paracetamol) Exposures: A Profile of Life-Threatening and Fatal Outcomes.Clin Toxicol. 2011;49(3):208.

9.Susan E Farrell, MD. Acetaminophen Toxicity.     


Acetaminophen-What every caregiver should know.

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