Get advice for managing Multiple Sclerosis: Watch the video.

acetaminophen

Pronunciation

Generic Name: acetaminophen (injection) (a SEET a MIN oh FEN)
Brand Name: Ofirmev

What is acetaminophen injection?

Acetaminophen is a pain reliever and a fever reducer.

Acetaminophen injection is used to treat pain and to reduce fever. Acetaminophen injection is sometimes given with opioid (sometimes called narcotic) pain medication to treat moderate to severe pain.

Acetaminophen injection may also be used for purposes not listed in this medication guide.

What is the most important information I should know about acetaminophen injection?

You should not use this medication if you have severe liver disease.

Do not use more of this medication than is recommended. An overdose of acetaminophen can damage your liver or cause death. Call your doctor at once if you have nausea, pain in your upper stomach, itching, loss of appetite, dark urine, clay-colored stools, or jaundice (yellowing of your skin or eyes).

Slideshow: Living with Your Migraines: Tips for Treatment and Prevention

Be very careful when measuring your dose. This medicine contains 10 milligrams (mg) of acetaminophen in each milliliter (mL) of the solution.

In rare cases, acetaminophen may cause a severe skin reaction that can be fatal. Stop using this medicine and call your doctor right away if you have skin redness or a rash that spreads and causes blistering and peeling.

What should I discuss with my healthcare provider before using acetaminophen injection?

You should not use this medication if you are allergic to acetaminophen, or if you have severe liver disease.

Tell your doctor if you have ever had liver disease, or if you drink more than 3 alcoholic beverages per day.

To make sure acetaminophen is safe for you, tell your doctor if you have:

  • kidney disease; or

  • if you are malnourished.

FDA pregnancy category C. Your doctor will determine whether acetaminophen is safe for you to use during pregnancy. Tell your doctor if you are pregnant or plan to become pregnant while using this medication.

Acetaminophen can pass into breast milk and may harm a nursing baby. Tell your doctor if you are breast-feeding a baby.

Acetaminophen injection should not be given to a child younger than 2 years old.

How is acetaminophen injection given?

This medicine is injected into a vein through an IV. You may be shown how to use an IV at home. Do not self-inject this medicine if you do not fully understand how to give the injection and properly dispose of used needles, IV tubing, and other items used to inject the medicine.

Be very careful when measuring your dose. This medicine contains 10 milligrams (mg) of acetaminophen in each milliliter (mL) of the solution. If your dose is 1000 mg, for example, you would use only 100 mL of solution.

If you are using an infusion pump, take care to properly program the machine to deliver the correct amount of medicine for your dose.

Tell your doctor if you have any changes in weight while using this medicine. Lower doses are used in people who weigh less than 110 pounds (50 kilograms).

Do not use more of this medication than is recommended. An overdose of acetaminophen can damage your liver or cause death.

Acetaminophen injection is usually given once every 4 to 6 hours. Follow your doctor's dosing instructions very carefully.

Each single use vial (bottle) of this medicine is for one use only. Throw away after one use, even if there is still some medicine left in it after injecting your dose.

Store at room temperature away from heat and moisture. Do not refrigerate or freeze.

You must use the medication within 6 hours after opening a vial.

What happens if I miss a dose?

Since acetaminophen is used as needed, you may not be on a dosing schedule. If you are using the medication regularly, use the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not use extra medicine to make up the missed dose.

Do not use acetaminophen injection more often than every 4 hours.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. An overdose of acetaminophen can be fatal.

The first signs of an acetaminophen overdose include loss of appetite, nausea, vomiting, stomach pain, sweating, and confusion or weakness. Later symptoms may include pain in your upper stomach, dark urine, and yellowing of your skin or the whites of your eyes.

Overdose symptoms may also include hunger with irritability, fast heart rate, tremors, feeling jittery, trouble concentrating, easy bruising, unusual bleeding, or purple or red pinpoint spots under your skin.

What should I avoid while using acetaminophen injection?

Ask a doctor or pharmacist before using any other cold, allergy, pain, or sleep medication. Acetaminophen (sometimes abbreviated as APAP) is contained in many combination medicines. Taking certain products together can cause you to get too much acetaminophen which can lead to a fatal overdose. Check the label to see if a medicine contains acetaminophen or APAP.

Avoid drinking alcohol. It may increase your risk of liver damage while taking acetaminophen.

Acetaminophen injection side effects

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

In rare cases, acetaminophen may cause a severe skin reaction that can be fatal. This could occur even if you have taken acetaminophen in the past and had no reaction. Stop using this medicine and call your doctor right away if you have skin redness or a rash that spreads and causes blistering and peeling. If you have this type of reaction, you should never again take any medicine that contains acetaminophen.

Stop using acetaminophen and call your doctor at once if you have:

  • chest pain, trouble breathing; or

  • liver problems--nausea, upper stomach pain, itching, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Common side effects may include:

  • vomiting;

  • constipation;

  • feeling agitated;

  • headache; or

  • sleep problems (insomnia).

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

See also: Side effects (in more detail)

Acetaminophen dosing information

Usual Adult Dose for Fever:

IV:
Adults and adolescents weighing 50 kg and over: 1000 mg every 6 hours or 650 mg every 4 hours, with a maximum single dose of 1000 mg, a minimum dosing interval of 4 hours, and a maximum daily dose of acetaminophen of 4000 mg per day.
Adults and adolescents weighing under 50 kg: 15 mg/kg every 6 hours or 12.5 mg/kg every 4 hours, with a maximum single dose of 15 mg/kg, a minimum dosing interval of 4 hours, and a maximum daily dose of acetaminophen of 75 mg/kg per day.

Orally or Rectally:
General Dosing Guidelines: 325 to 650 mg every 4 to 6 hours or 1000 mg every 6 to 8 hours

No dose adjustment is required when converting between oral and IV acetaminophen dosing in adults and adolescents. The maximum daily dose of acetaminophen is based on all routes of administration
(i.e. intravenous, oral, and rectal) and all products containing acetaminophen.

Usual Adult Dose for Pain:

IV:
Adults and adolescents weighing 50 kg and over: 1000 mg every 6 hours or 650 mg every 4 hours, with a maximum single dose of 1000 mg, a minimum dosing interval of 4 hours, and a maximum daily dose of acetaminophen of 4000 mg per day.
Adults and adolescents weighing under 50 kg: 15 mg/kg every 6 hours or 12.5 mg/kg every 4 hours, with a maximum single dose of 15 mg/kg, a minimum dosing interval of 4 hours, and a maximum daily dose of acetaminophen of 75 mg/kg per day.

Orally or Rectally:
General Dosing Guidelines: 325 to 650 mg every 4 to 6 hours or 1000 mg every 6 to 8 hours

No dose adjustment is required when converting between oral and IV acetaminophen dosing in adults and adolescents. The maximum daily dose of acetaminophen is based on all routes of administration
(i.e. intravenous, oral, and rectal) and all products containing acetaminophen.

Usual Pediatric Dose for Fever:

Preterm neonates 28 to 32 weeks:
IV loading dose: 20 mg/kg followed by 10 mg/kg/dose every 12 hours
Oral: 10 to 12 mg/kg/dose every 6 to 8 hours
Maximum oral daily dose: 40 mg/kg/day
Rectal: 20 mg/kg/dose every 12 hours
Maximum rectal daily dose: 40 mg/kg/day

Preterm neonates 32 to 37 weeks and term neonates less than 10 days:
IV loading dose: 20 mg/kg followed by 10 mg/kg/dose every 6 hours
Oral: 10 to 15 mg/kg/dose every 6 hours
Maximum daily dose: 60 mg/kg/day
Rectal: Loading dose: 30 mg/kg; then 15 mg/kg/dose every 8 hours
Maximum daily dose: 60 mg/kg/day

Term neonates greater than or equal to 10 days:
IV loading dose: 20 mg/kg followed by 10 mg/kg/dose every 6 hours
Oral: 10 to 15 mg/kg/dose every 4 to 6 hours
Maximum daily dose: 90 mg/kg/day
Rectal: Loading dose: 30 mg/kg; then 20 mg/kg/dose every 6 to 8 hours
Maximum daily dose: 90 mg/kg/day

Infants and Children:
IV: Less than 2 years: 7.5 to 15 mg/kg/dose every 6 hours
Maximum daily dose: 60 mg/kg/day
IV: 2 to 12 years: 15 mg/kg every 6 hours or 12.5 mg/kg every 4 hours
Maximum single dose 15 mg/kg
Maximum total daily dose: 75 mg/kg/day not to exceed 3750 mg/day
Oral: 10 to 15 mg/kg/dose every 4 to 6 hours as needed; do not exceed 5 doses in 24 hours
Alternatively, the manufacturer lists the following recommended doses:
2.7 to 5.3 kg or 6 to 11 pounds: 0 to 3 months: 40 mg
5.4 to 8.1 kg or 12 to 17 pounds: 4 to 11 months: 80 mg
8.2 to 10.8 kg or 18 to 23 pounds: 1 to 2 years: 120 mg
10.9 to 16.3 kg or 24 to 35 pounds: 2 to 3 years: 160 mg
16.4 to 21.7 kg or 36 to 47 pounds: 4 to 5 years: 240 mg
21.8 to 27.2 kg or 48 to 59 pounds: 6 to 8 years: 320 mg
27.3 to 32.6 kg or 60 to 71 pounds: 9 to 10 years: 400 mg
32.7 to 43.2 kg or 72 to 95 pounds: 11 years: 480 mg
The manufacturer recommends the use of weight to select the dose as the preferred method. If weight is not available, then age may be used.
Rectal: 10 to 20 mg/kg/dose every 4 to 6 hours as needed (Although the perioperative use of high dose rectal acetaminophen (e.g., 25 to 45 mg/kg/dose) has been investigated in several studies, its routine use remains controversial; optimal doses and dosing frequency to ensure efficacy and safety have not yet been established; further studies are needed).

Children greater than or equal to 12 years:
IV: Less than 50 kg: 15 mg/kg every 6 hours or 12.5 mg/kg every 4 hours
Maximum single dose: 750 mg/dose
Maximum total daily dose: 75 mg/kg/day (less than or equal to 3750 mg/day)
IV: Greater than or equal to 50 kg: 650 mg every 4 hours or 1000 mg every 6 hours
Maximum single dose: 1000 mg/dose
Maximum total daily dose: 4000 mg/day
Oral or Rectal: 325 to 650 mg every 4 to 6 hours or 1,000 mg 3 to 4 times daily
Maximum daily dose: 4000 mg/day

Usual Pediatric Dose for Pain:

Preterm neonates 28 to 32 weeks:
IV loading dose: 20 mg/kg followed by 10 mg/kg/dose every 12 hours
Oral: 10 to 12 mg/kg/dose every 6 to 8 hours
Maximum oral daily dose: 40 mg/kg/day
Rectal: 20 mg/kg/dose every 12 hours
Maximum rectal daily dose: 40 mg/kg/day

Preterm neonates 32 to 37 weeks and term neonates less than 10 days:
IV loading dose: 20 mg/kg followed by 10 mg/kg/dose every 6 hours
Oral: 10 to 15 mg/kg/dose every 6 hours
Maximum daily dose: 60 mg/kg/day
Rectal: Loading dose: 30 mg/kg; then 15 mg/kg/dose every 8 hours
Maximum daily dose: 60 mg/kg/day

Term neonates greater than or equal to 10 days:
IV loading dose: 20 mg/kg followed by 10 mg/kg/dose every 6 hours
Oral: 10 to 15 mg/kg/dose every 4 to 6 hours
Maximum daily dose: 90 mg/kg/day
Rectal: Loading dose: 30 mg/kg; then 20 mg/kg/dose every 6 to 8 hours
Maximum daily dose: 90 mg/kg/day

Infants and Children:
IV: Less than 2 years: 7.5 to 15 mg/kg/dose every 6 hours
Maximum daily dose: 60 mg/kg/day
IV: 2 to 12 years: 15 mg/kg every 6 hours or 12.5 mg/kg every 4 hours
Maximum single dose 15 mg/kg
Maximum total daily dose: 75 mg/kg/day not to exceed 3750 mg/day
Oral: 10 to 15 mg/kg/dose every 4 to 6 hours as needed; do not exceed 5 doses in 24 hours
Alternatively, the manufacturer lists the following recommended doses:
2.7 to 5.3 kg or 6 to 11 pounds: 0 to 3 months: 40 mg
5.4 to 8.1 kg or 12 to 17 pounds: 4 to 11 months: 80 mg
8.2 to 10.8 kg or 18 to 23 pounds: 1 to 2 years: 120 mg
10.9 to 16.3 kg or 24 to 35 pounds: 2 to 3 years: 160 mg
16.4 to 21.7 kg or 36 to 47 pounds: 4 to 5 years: 240 mg
21.8 to 27.2 kg or 48 to 59 pounds: 6 to 8 years: 320 mg
27.3 to 32.6 kg or 60 to 71 pounds: 9 to 10 years: 400 mg
32.7 to 43.2 kg or 72 to 95 pounds: 11 years: 480 mg
The manufacturer recommends the use of weight to select the dose as the preferred method. If weight is not available, then age may be used.
Rectal: 10 to 20 mg/kg/dose every 4 to 6 hours as needed (Although the perioperative use of high dose rectal acetaminophen (e.g., 25 to 45 mg/kg/dose) has been investigated in several studies, its routine use remains controversial; optimal doses and dosing frequency to ensure efficacy and safety have not yet been established; further studies are needed).

Children greater than or equal to 12 years:
IV: Less than 50 kg: 15 mg/kg every 6 hours or 12.5 mg/kg every 4 hours
Maximum single dose: 750 mg/dose
Maximum total daily dose: 75 mg/kg/day (less than or equal to 3750 mg/day)
IV: Greater than or equal to 50 kg: 650 mg every 4 hours or 1000 mg every 6 hours
Maximum single dose: 1000 mg/dose
Maximum total daily dose: 4000 mg/day
Oral or Rectal: 325 to 650 mg every 4 to 6 hours or 1,000 mg 3 to 4 times daily
Maximum daily dose: 4000 mg/day

What other drugs will affect acetaminophen injection?

Other drugs may interact with acetaminophen, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.

Where can I get more information?

  • Your pharmacist can provide more information about acetaminophen.
  • Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.
  • Disclaimer: Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2012 Cerner Multum, Inc. Version: 2.02. Revision Date: 2014-02-07, 7:01:12 PM.

Hide
(web4)