2.1 Important Dosing and Administration Information

• DO NOT ADD SUPPLEMENTARY MEDICATION.
• Aseptic technique is required.
• Before use, perform the following checks: Read the label. Ensure solution is the one ordered and is within the expiration date.
• Inspect the solution in good light for cloudiness, haze or particulate matter; check the container for leakage or damage. Any container which is suspect should not be used.
• Use only if solution is clear and container and seals are intact. Single-dose plastic container. Discard unused portion. Consult Package Insert for complete product information.
• DO NOT USE PLASTIC CONTAINER IN SERIES CONNECTION.

Acetaminophen Injection may be given as a single or repeated dose for the treatment of acute pain or fever. No dose adjustment is required when converting between oral acetaminophen and Acetaminophen Injection dosing in adults and adolescents who weigh 50 kg and above. Calculated maximum daily dose of acetaminophen is based on all routes of administration (i.e. intravenous, oral, and rectal) and all products containing acetaminophen. Exceeding the maximum mg/kg daily dose of acetaminophen as described in Tables 1-3 may result in hepatic injury, including the risk of liver failure and death. To avoid the risk of overdose, ensure that the total amount of acetaminophen from all routes and from all sources does not exceed the maximum recommended dose.

2.2 Recommended Dosage: Adults and Adolescents

Adults and adolescents weighing 50 kg and over: the recommended dosage of Acetaminophen Injection is 1,000 mg every 6 hours or 650 mg every 4 hours, with a maximum single dose of Acetaminophen Injection of 1,000 mg, a minimum dosing interval of 4 hours, and a maximum daily dose of acetaminophen of 4,000 mg per day (includes all routes of administration and all acetaminophen-containing products including combination products).

Adults and adolescents weighing under 50 kg: the recommended dosage of Acetaminophen Injection is 15 mg/kg every 6 hours or 12.5 mg/kg every 4 hours, with a maximum single dose of Acetaminophen Injection of 15 mg/kg, a minimum dosing interval of 4 hours, and a maximum daily dose of acetaminophen of 75 mg/kg per day (includes all routes of administration and all acetaminophen-containing products including combination products).

2.3 Recommended Dosage: Children

Children 2 to 12 years of age: the recommended dosage of Acetaminophen Injection is 15 mg/kg every 6 hours or 12.5 mg/kg every 4 hours, with a maximum single dose of Acetaminophen Injection of 15 mg/kg, a minimum dosing interval of 4 hours, and a maximum daily dose of acetaminophen of 75 mg/kg per day.

2.4 Recommended Dosage For Treatment of Fever in Neonates and Infants

Neonates, including premature neonates born at greater than or equal to 32 weeks gestational age, up to 28 days chronological age: the recommended dosage of Acetaminophen Injection is 12.5 mg/kg every 6 hours, to a maximum daily dose of acetaminophen of 50 mg/kg per day, with a minimum dosing interval of 6 hours.

Infants 29 days to 2 years of age: the recommended dosage of Acetaminophen Injection is 15 mg/kg every 6 hours, to a maximum daily dose of acetaminophen of 60 mg/kg per day, with a minimum dosing interval of 6 hours.

2.5 Instructions for Intravenous Administration from PAB® Container

DO NOT ADD SUPPLEMENTARY MEDICATION.

Aseptic technique is required.

Before use, perform the following checks: Read the label. Ensure solution is the one ordered and is within the expiration date.

Inspect the solution in good light for cloudiness, haze or particulate matter; check the container for leakage or damage. Any container which is suspect should not be used.

Use only if solution is clear and container and seals are intact. Single dose plastic container. Discard unused portion. Consult Package Insert for complete product information.

DO NOT USE PLASTIC CONTAINER IN SERIES CONNECTION.

This solution is intended for intravenous administration over 15 minutes using sterile equipment. It is recommended that intravenous administration apparatus be replaced at least once every 24 hours.

1. Identify Two Ports (See Figure A).

2. To Attach Administration Set

To aseptically remove the set port closure: hold container below the set port and grasp the foil tab between the thumb and forefinger then pull the tab in two steps as shown in Figure B Steps 1 and 2.

3. Push spike through the diaphragm of the port (See Figure C). Hang container using hole on the lower flap. Prime set in accordance with the Directions for Use provided with the set in use.

PAB® containers can be safely transported in a standard 6-inch carrier through a pneumatic tube system that is well maintained and running properly.

2.6 Instructions for Intravenous Administration of Doses Not Equivalent to 500 mg or 1,000 mg

Doses that are not equivalent to 500 mg or 1,000 mg require aseptic transfer to a separate container prior to dispensing. Discard unused portion. Using aseptic technique, withdraw the appropriate dose (650 mg or weight-based) from an intact sealed PAB container and place the measured dose in a separate empty, sterile container (e.g., glass bottle, plastic intravenous container, or syringe) for intravenous infusion to avoid the inadvertent delivery and administration of the total volume of the commercially available container. The entire 100 mL container is not intended for use in patients weighing less than 50 kg. Acetaminophen injection is supplied in a single-dose container and the unused portion must be discarded.

Place small volume pediatric doses up to 60 mL in volume in a syringe and administer over 15 minutes using a syringe pump.

5.1 Hepatic Injury

Administration of acetaminophen in doses higher than recommended may result in hepatic injury, including the risk of liver failure and death [see Overdosage (10)]. Do not exceed the maximum recommended daily dose of acetaminophen [see Dosage and Administration (2)]. The maximum recommended daily dose of acetaminophen includes all routes of acetaminophen administration and all acetaminophen-containing products administered, including combination products.

Use caution when administering acetaminophen in patients with the following conditions: hepatic impairment or active hepatic disease, alcoholism, chronic malnutrition, severe hypovolemia (e.g., due to dehydration or blood loss), or severe renal impairment (creatinine clearance less than or equal to 30 mL/min) [see Use In Specific Populations (8.6, 8.7)].

5.2 Serious Skin Reactions

Rarely, acetaminophen may cause serious skin reactions such as acute generalized exanthematous pustulosis (AGEP), Stevens-Johnson Syndrome (SJS), and toxic epidermal necrolysis (TEN), which can be fatal. Patients should be informed about the signs of serious skin reactions, and use of the drug should be discontinued at the first appearance of skin rash or any other sign of hypersensitivity.

5.3 Risk of Medication Errors

Take care when prescribing, preparing, and administering Acetaminophen Injection in order to avoid dosing errors which could result in accidental overdose and death. In particular, be careful to ensure that:

• the dose in milligrams (mg) and milliliters (mL) is not confused;
• the dosing is based on weight for patients under 50 kg;
• infusion pumps are properly programmed; and
• the total daily dose of acetaminophen from all sources does not exceed maximum daily limits [see Dosage and Administration (2)].

5.4 Allergy and Hypersensitivity

There have been post-marketing reports of hypersensitivity and anaphylaxis associated with the use of acetaminophen. Clinical signs included swelling of the face, mouth, and throat, respiratory distress, urticaria, rash, and pruritus. There were infrequent reports of life-threatening anaphylaxis requiring emergent medical attention. Discontinue Acetaminophen Injection immediately if symptoms associated with allergy or hypersensitivity occur. Do not use Acetaminophen Injection in patients with acetaminophen allergy.

6.1 Clinical Trial Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed cannot be directly compared to rates in other clinical trials and may not reflect the rates observed in practice.

7.1 Effects of other Substances on Acetaminophen

Substances that induce or regulate hepatic cytochrome enzyme CYP2E1 may alter the metabolism of acetaminophen and increase its hepatotoxic potential. The clinical consequences of these effects have not been established. Effects of ethanol are complex, because excessive alcohol usage can induce hepatic cytochromes, but ethanol also acts as a competitive inhibitor of the metabolism of acetaminophen.

7.2 Anticoagulants

Chronic oral acetaminophen use at a dose of 4,000 mg/day has been shown to cause an increase in international normalized ratio (INR) in some patients who have been stabilized on sodium warfarin as an anticoagulant. As no studies have been performed evaluating the short-term use of Acetaminophen Injection in patients on oral anticoagulants, more frequent assessment of INR may be appropriate in such circumstances.

8.1 Pregnancy

8.2 Lactation

8.3 Females and Males of Reproductive Potential

Based on animal data use of acetaminophen may cause reduced fertility in males and females of reproductive potential. It is not known whether these effects on fertility are reversible. Published animal studies reported that oral acetaminophen treatment of male animals at doses that are 1.2 times the MHDD and greater (based on a body surface area comparison) result in decreased testicular weights, reduced spermatogenesis, and reduced fertility. In female animals given the same doses, reduced implantation sites were reported. Additional published animal studies indicate that acetaminophen exposure in utero adversely impacts reproductive capacity of both male and female offspring at clinically relevant exposures [see Nonclinical Toxicology (13.1)].

8.4 Pediatric Use

Treatment of Acute Pain

The safety and effectiveness of Acetaminophen Injection for the treatment of acute pain in pediatric patients ages 2 years and older is supported by evidence from adequate and well-controlled studies of Acetaminophen Injection in adults and safety and pharmacokinetic data from adult and 483 pediatric patients across all age groups [see Dosage and Administration (2.3) and Pharmacokinetics (12.3)].

The effectiveness of Acetaminophen Injection for the treatment of acute pain in pediatric patients younger than 2 years of age has not been established.

In patients younger than 2 years, efficacy was not demonstrated in a double-blind, placebo-controlled study of 198 pediatric patients younger than 2 years. Pediatric patients less than 2 years of age, including neonates from 28 to 40 weeks gestational age at birth, were randomized to receive opioid plus acetaminophen or opioid plus placebo. No difference in analgesic effect of intravenous acetaminophen, measured by assessment of reduced need for additional opioid treatment for pain control, was observed.

Treatment of Fever

The safety and effectiveness of Acetaminophen Injection for the treatment of fever in pediatric patients, including premature neonates born at greater than or equal to 32 weeks gestational age is supported by adequate and well-controlled studies of Acetaminophen Injection in adults, clinical studies in 244 pediatric patients 2 years and older, and safety and pharmacokinetic data from 239 patients younger than 2 years including neonates greater than or equal to 32 weeks gestational age. 

8.5 Geriatric Use

Of the total number of subjects in clinical studies of acetaminophen, 15% were age 65 and over, while 5% were age 75 and over. No overall differences in safety or effectiveness were observed between these subjects and younger subjects, and other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out.

8.6 Patients with Hepatic Impairment

Acetaminophen is contraindicated in patients with severe hepatic impairment or severe active liver disease and should be used with caution in patients with hepatic impairment or active liver disease [see Warnings and Precautions (5.1) and Clinical Pharmacology (12)]. A reduced total daily dose of acetaminophen may be warranted.

8.7 Patients with Renal Impairment

In cases of severe renal impairment (creatinine clearance less than or equal to 30 mL/min), longer dosing intervals and a reduced total daily dose of acetaminophen may be warranted.

12.1 Mechanism of Action

The precise mechanism of the analgesic and antipyretic properties of acetaminophen is not established but is thought to primarily involve central actions.

12.2 Pharmacodynamics

Acetaminophen has been shown to have analgesic and antipyretic activities in animal and human studies. Single doses of acetaminophen up to 3,000 mg and repeated doses of 1,000 mg every 6 hours for 48 hours have not been shown to cause a significant effect on platelet aggregation. Acetaminophen does not have any immediate or delayed effects on small-vessel hemostasis. Clinical studies of both healthy subjects and patients with hemophilia showed no significant changes in bleeding time after receiving multiple doses of oral acetaminophen.        

12.3 Pharmacokinetics

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility

14.1 Adult Acute Pain

The efficacy of Acetaminophen Injection in the treatment of acute pain in adults was evaluated in two randomized, double-blind, placebo-controlled clinical trials in patients with postoperative pain.

Pain Study 1 evaluated the analgesic efficacy of repeated doses of acetaminophen 1,000 mg vs. placebo every 6 hours for 24 hours in 101 patients with moderate to severe pain following total hip or knee replacement. Acetaminophen Injection was statistically superior to placebo for reduction in pain intensity over 24 hours. There was an attendant decrease in opioid consumption, the clinical benefit of which was not demonstrated.

Pain Study 2 evaluated the analgesic efficacy of repeated doses of acetaminophen 1,000 mg every 6 hours or 650 mg every 4 hours for 24 hours versus placebo in the treatment of 244 patients with moderate to severe postoperative pain after abdominal laparoscopic surgery. Patients receiving acetaminophen experienced a statistically significant greater reduction in pain intensity over 24 hours compared to placebo.

14.2 Adult Fever

The efficacy of acetaminophen 1,000 mg in the treatment of adult fever was evaluated in one randomized, double-blind, placebo-controlled clinical trial. The study was a 6-hour, single-dose, endotoxin-induced fever study in 60 healthy adult males. A statistically significant antipyretic effect of acetaminophen was demonstrated through 6 hours in comparison to placebo. The mean temperature over time is shown in Figure 1.

Figure 1:       Mean Temperature (°C) Over Time

14.3  Pediatric Acute Pain and Fever

Acetaminophen was studied in pediatric patients in three active-controlled trials and three open-label safety and pharmacokinetic trials [see Use in Specific Populations (8.4)].