Acetaminophen (Tylenol) Poisoning

Acetaminophen is one of the most common medications found in households. It is used for the treatment of pain and to lower fever.

Over many years, it has been used countless times by many people and it has proven to be a safe and effective medication. However, if taken in excess amounts (overdose, whether on purpose or by accident), acetaminophen can cause life-threatening illness.

• Acetaminophen is the active ingredient in Tylenol. It is also found in many other over-the-counter medications you can buy at the drug store and in prescription drugs your doctor prescribes: Common names include Actifed, Alka-Seltzer Plus, Benadryl, Butalbital, Co-Gesic, Contac, Darvocet, Excedrin, Fioricet, Lortab, Midrin, Norco, Percocet, Robitussin, Sedapap, Sinutab, Sudafed, TheraFlu, Unisom With Pain, Vick's Nyquil and DayQuil, Vicodin, Wygesic, and Zydone.
  
  
• Acetaminophen in overdose can seriously damage the liver. If the damage is severe, a liver transplant may be necessary in order to save a life.
  
  
  • The antidote to acetaminophen overdose is N-acetylcysteine (NAC). It is most effective when given within 8 hours of ingesting acetaminophen. Indeed, NAC can prevent liver failure if given early enough. For this reason, it is absolutely necessary that acetaminophen poisoning be recognized, diagnosed, and treated as early as possible.

Illness from acetaminophen overdose is caused primarily by liver damage.

• Acetaminophen is primarily metabolized by the liver. Too much acetaminophen can overwhelm the way the liver normally functions.

• If the liver is already damaged because of infection, alcohol abuse, or other illness, a person may be more susceptible to damage from acetaminophen overdose. For this reason, people with liver illnesses or people who chronically consume large amounts of alcohol should be particularly careful when taking acetaminophen and should consult their doctor prior to taking acetaminophen compounds. The US Food and Drug Administration (FDA) currently recommends that anyone consuming more than 3 alcoholic beverages per day should not take acetaminophen or other over-the-counter pain medications.

• Long-term use of acetaminophen in recommended doses has not been shown to be harmful to the liver, even when combined with moderate alcohol consumption.

Soon after taking an overdose of acetaminophen, you may have no symptoms from taking a toxic amount. You may remain symptom free for up to 24 hours after taking a toxic overdose of acetaminophen.

After this initial period, the following symptoms are common:

• Nausea

• Vomiting

• Not feeling well

• Not able to eat or poor appetite

• Abdominal pain

You must call a doctor, a poison control center, or emergency medical services for any suspected acetaminophen overdose.

Overall it is important that anyone suspected to have taken an overdose of acetaminophen get treatment early, before symptoms occur. Starting treatment early can greatly improve the outcome.

Seek emergency medical care at a hospital's emergency department.

• If the person suspected to have taken an overdose of acetaminophen is unconscious, semiconscious, or not breathing, call 911 immediately.

• Go to the hospital's emergency department if the poison control center tells you to go.

• Seek emergency care if you are unsure of the types and amounts of medication taken.

• If a child took acetaminophen without adult supervision and may have taken an overdose, seek immediate medical attention.

Your doctor will diagnose acetaminophen overdose with the following methods:

• History: The doctor will attempt to determine the time and amount of acetaminophen taken. Having access to all medication bottles that the person may have taken will help the doctor to determine the maximum amount taken.

• Physical: The doctor will look for signs and symptoms of acetaminophen poisoning. These may include jaundice (yellow skin), abdominal pain, vomiting, and other signs and symptoms.

• Laboratory tests: A blood level of acetaminophen will aid in determining if a toxic dose was taken. The doctor may order more than one blood level of acetaminophen and test for other drugs taken. In addition, the doctor may order other blood and urine tests as needed.

|Self-Care at Home|

If you or a member of your household has taken or may have taken an overdose of acetaminophen, take quick action.

• If the person is unconscious or not breathing, call 911 immediately for emergency medical services.
  
  
• If the person is awake and breathing without symptoms, call your local poison control center or the American Association of Poison Control Centers at (800) 222-1222.

The following information is helpful for both medical personnel and a poison control center:

• All medication that the person has taken, both prescribed and unprescribed (have the bottles close)
  
  

• All medications that are available in the house, prescribed and unprescribed
  
  
• The time that the person took the medication

|Medical Treatment|

Treatment in the emergency department depends on the condition of the person and any other medications taken.

If someone is suspected of having taken an overdose but has no symptoms, the doctor will begin the following treatment:

• Emptying of the stomach: In the very few cases in which a person comes to the hospital minutes after taking the overdose, the doctor may attempt to empty the stomach. This can be accomplished by inducing vomiting or by placing a large tube through the person's mouth and into the stomach.

• N-acetylcysteine (NAC): NAC is the antidote for toxic acetaminophen overdose. It is generally given by mouth. The medication has a foul odor but may be mixed with juice or other flavorings to make it taste better. If the person cannot take NAC by mouth, a tube may be placed through the mouth and into the stomach to help administer it. If giving NAC by this method is not possible, the doctor may give it by IV. NAC is generally given for 20-72 hours.

• Activated charcoal: Activated charcoal can be given by mouth to bind any drug remaining in the gastrointestinal tract.

|Follow-up|

After being discharged from the hospital or doctor's office, you may be asked to return for an examination or blood tests to check the condition of your liver and your general health. Your doctor may instruct you to avoid alcohol and certain medications.

|Prevention|

You can take these steps to avoid acetaminophen overdose.

• Always securely close acetaminophen containers and use child-proof bottles. Keep all medication out of the reach of children and securely locked up.
  
  
• Know the correct dose of acetaminophen and the amount of acetaminophen in the preparation you are using. If taken in recommended doses, there is no risk of poisoning from acetaminophen.
  
  
• Never mix different medications if both medications contain acetaminophen, except if instructed to do so by your doctor. For example, acetaminophen with codeine and cold medicine containing acetaminophen should not be taken together. Read product labels. They clearly indicate the contents.
  
  
• If you or a family member is depressed or suicidal, remove all medications and dangerous substances from the house and seek medical attention immediately.
  
  
• If you are unsure about how and when to take pain medications, ask your doctor for a plan. Write this plan down and follow it.
  
  
• When you are given a new medication, always make sure the doctor knows all of the medication and supplements that you are taking, both prescribed and non-prescribed. The easiest way to do this is to keep a written list of medications and supplements and go over it with your doctor.
  
  
• Do not take acetaminophen if you consume more than 3 alcoholic beverages per day. Indeed, if you consume more than 3 alcoholic beverages per day, you should consult a physician before taking any pain medications and to discuss ways to reduce your alcohol consumption.

|Outlook|

The outcome for someone who has an acetaminophen overdose depends largely on 3 factors: the amount of acetaminophen ingested, the timing of emergency treatment, and the initial general health of the person.

• If a toxic dose is taken and emergency treatment is delayed, liver failure may follow. Liver failure may mean that a liver transplant is needed. Alternatively, if treatment of a toxic overdose is begun early, the person may recover with no long-term health problems.

|Web Links|

MedlinePlus, Acetaminophen overdose

MedlinePlus, Poisoning

APAP, Tylenol, N-acetyl-p-aminophenol, N-acetylcysteine, NAC, paracetamol, acetaminophen toxicity, Tylenol toxicity, overdose, poisoning, Actifed, Alka-Seltzer Plus, Benadryl, Butalbital, Co-Gesic, Contac, Darvocet, Excedrin, Fioricet, Lortab, Midrin, Norco, Percocet, Robitussin, Sedapap, Sinutab, Sudafed, TheraFlu, Unisom With Pain, Vick's Nyquil, DayQuil, Vicodin, Wygesic, Zydone, Tylenol poisoning, acetaminophen poisoning, medication overdose, drug overdose

Author: Michael J Ameres, MD, Consulting Staff, Department of Emergency Medicine, Southampton Hospital.

Coauthor(s): Daniel Crough, MD, Consulting Staff, Department of Emergency Medicine, Southampton Hospital.

Editors: Michael D Burg, MD, Assistant Clinical Professor, Department of Emergency Medicine, University Medical Center, University of California at San Francisco-Fresno; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, ; Anthony Anker, MD, FAAEM, Attending Physician, Emergency Department, Mary Washington Hospital, Fredericksburg, VA.