Acetaminophen

Acetaminophen is a pain reliever that is available over the counter. It works by blocking the body's production of prostaglandins, which are naturally occurring chemicals that cause inflammation and fever. There are many forms of acetaminophen available, including tablets, gel tabs, caplets, chewable tablets, and liquid. Potential side effects of the medication include liver damage, ulcers or bleeding in the digestive tract, and allergic reactions.

 

What Is Acetaminophen?

Acetaminophen (Tylenol®) is a non-prescription pain reliever and fever reducer. It is one of the most commonly used non-prescription medications. Compared to other non-prescription pain relievers, it is less likely to cause ulcers and to interact with other medications. However, it may be more likely to cause liver damage, especially when taken at very high doses or in people who already have liver damage.
 
This article refers to acetaminophen that is taken by mouth for adults and children age 12 and older. For information on acetaminophen for younger children or infants, see Children's Tylenol and Infant Tylenol.
 
(Click What Is Acetaminophen Used For? for more information on this medication, including possible off-label uses.)
 

Who Makes Acetaminophen?

Acetaminophen is made by McNeil Consumer Healthcare. There are numerous generic versions of acetaminophen, made by several different generic manufacturers.
 

How Does It Work?

Even though acetaminophen has been around for quite a while, it is not fully understood exactly how it works. It is known that it works differently from any other non-prescription medication. Most other non-prescription pain relievers or fever reducers are nonsteroidal anti-inflammatory drugs (NSAIDS). Both NSAIDS and acetaminophen block the body's production of prostaglandins (naturally occurring chemicals that cause inflammation and fever). However, while NSAIDS block prostaglandin production throughout the body, acetaminophen appears to do so just in the central nervous system (the brain and spinal cord). It may also work by blocking pain signals from nerves (or preventing such signals from forming).
 

When and How to Take Acetaminophen

General considerations for when and how to take acetaminophen include the following:
 
  • Acetaminophen comes in a variety of forms, including tablets, caplets, gel tabs, chewable tablets, and liquid. It is usually taken by mouth every four to six hours as needed.
     
  • Two long-acting forms are also available: Tylenol Arthritis Pain and Tylenol 8 Hour. These products contain one layer that dissolves quickly for rapid pain relief and a second layer that dissolves slowly. These products are taken every eight hours.
     
  • It can be taken with or without food. If the drug bothers your stomach, try taking it with food.
     
  • It is important to keep track of how much you take, as it is easy to take too much (see Tylenol Poisoning). It is important to remember that acetaminophen is found in many medications (both prescription and non-prescription).
     
  • For the medication to work properly, it must be taken as prescribed.
     

Dosing Information

Your recommended dose will vary depending on a number of factors, including:
 
  • Your age
  • The particular acetaminophen product
  • Other medications you may be taking
  • Other medical conditions you may have.
     
As is always the case, do not adjust your acetaminophen dose unless your healthcare provider specifically instructs you to do so.
 
(Click Acetaminophen Dosage for more information.)
 

Side Effects of Acetaminophen

As with any medicine, side effects are possible. However, not everyone who takes the drug will experience side effects. In fact, most people tolerate it quite well. If side effects do occur, in most cases, they are minor and either require no treatment or can easily be treated by you or your healthcare provider. Serious side effects are less common.
 
Possible serious side effects include, but are not limited to:
 
  • Allergic reactions
  • Liver damage
  • Ulcers or bleeding in the digestive tract.
     
(Click Acetaminophen Side Effects to learn more, including potentially serious side effects that you should report immediately to your healthcare provider.)
 

Drug Interactions With Acetaminophen

The drug can potentially interact with several medications (see Drug Interactions With Acetaminophen).
 

What Should I Tell My Healthcare Provider?

You should talk with your healthcare provider prior to taking acetaminophen if you have:
 
  • Liver disease, such as cirrhosis, liver failure, or hepatitis
  • G6PD deficiency (a certain enzyme deficiency)
  • Any allergies, including allergies to food, dyes, or preservatives.
     
Also, let your healthcare provider know if you:
 
  • Are pregnant or thinking of becoming pregnant
  • Are breastfeeding
  • Drink alcohol regularly.
     
Make sure to tell your healthcare provider about all other medicines you are taking, including prescription and non-prescription medicines, vitamins, and herbal supplements.
 
(Click Precautions and Warnings With Acetaminophen to learn more, including information on who should not take acetaminophen.)
 

What If I Take an Overdose?

People who take too much acetaminophen may have overdose symptoms that could include:
 
  • Nausea and vomiting
  • Appetite loss
  • Sweating
  • Irritability
  • Abdominal pain, especially near the liver (the upper right part of the abdomen)
  • Diarrhea
  • Yellow eyes or skin
  • Liver failure
  • Kidney failure
  • Heart problems
  • Coma
  • Seizures
  • Loss of life.
     
If you happen to overdose, seek medical attention immediately.
 
(Click Acetaminophen Overdose for more information.)
 

Storage Methods

Acetaminophen should be stored at room temperature, away from moisture and heat. It should be stored in an airtight container.
 
Keep this medication and all other medications out of the reach of children.
 

What Should I Do If I Miss a Dose?

Most people take acetaminophen occasionally, just when they need it. However, sometimes healthcare providers recommend that some people take it on a daily basis. If you do not take your dose as scheduled, take your missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and continue with your regular schedule. Do not take a double dose.
 

Strengths of Acetaminophen

The medication is available in several different forms and strengths. Adult acetaminophen comes in three different strengths: 325 mg (regular strength), 500 mg (extra strength), and 650 mg (extended-release). It is also available in rectal suppositories (see Acetaminophen Suppositories).
 
Various forms of acetaminophen are also available for infants and children under the age of 12 (see Children's Tylenol and Infant Tylenol for more information).
 

Is There a Generic Version of Acetaminophen?

Currently, there are many different versions of generic acetaminophen available (see Generic Tylenol).