Acetaminophen Nursing Implications
Acetaminophen Nursing Responsibilities
Acetaminophen, also known as Tylenol or paracetamol, is a common over-the-counter drug used as a pain reliever and fever reducer. It is used so frequently by many people that various drugs are combined with paracetamol and are used as one of the medications for different medical conditions.
Because of being readily available, higher risks of acetaminophen overdose and poisoning may occur, especially to those in the at-risk groups.
Dosage and Indications of Acetaminophen
Acetaminophen or paracetamol is used as either or both an analgesic and antipyretic. The adult dosages are as follows:
- Immediate-release form
- For regular strength: 325-650 mg per mouth every 4 hours as needed; The dose should not exceed 3250 mg/day when unsupervised. Daily doses of up to 4 grams per day may be taken but under the supervision of a healthcare professional.
- For extra strength: 1000 mg per mouth every 6 to 8 hours as needed and should not exceed 3000 mg/day; Daily doses of 4 grams per day may be ingested under the guidance of a healthcare professional.
- Extended-release form: Two capsules (1300mg) per mouth every 8 hours as needed and dose should not exceed 3.9 grams per day
- Parenteral form (Intravenous or intramuscularly): 300 mg every 4 hours as needed and dose should not exceed 4 grams per day.
- Maximum dose: For acetaminophen containing products, doses should not exceed cumulative doses of 3.25 grams per day. However, doses may reach up to 4 grams per day provided that a healthcare professional is present.
The dosage form and strengths of acetaminophen are as follows:
- Tablet: 325mg, 500 mg
- Caplet: 325mg, 500mg, 650mg,
- Capsule: 325mg, 500mg,
- Caplet, extended release: 650mg
- Tablet, Oral-disintegrating: 80mg, 160mg
- Tablet, chewable: 80mg
- Solution or suspension, oral: 160mg/5ml
- Liquid oral: 160mg/5ml, 500mg/5ml
- Syrup oral: 160mg/5ml
- Ampule, IV: 300mg/2ml
Pharmacology of Acetaminophen
Mechanism of Action:
- Acetaminophen can act on the hypothalamus, producing direct antipyresis effect to the body
- In addition, paracetamol may work in blocking the generation of pain impulses when administered peripherally. Furthermore, paracetamol may affect prostaglandin synthesis in the central nervous system (CNS), thereby inhibiting pain impulses.
- The peak plasma time of paracetamol differs, depending on its form. For oral immediate release it’s 10-60 minutes. For oral extended release it’s 60-120 minutes. It takes 6 hours for conventional 500 mg tablets to have its peak effect and 8 hours for a 650 mg extended-release tablet. For the parenteral form of 300mg/5ml ampule, it takes 30 minutes for the peak to take place.
- Peak plasma concentrations of Acetaminophen are as follows: 2.1mcg.ml for a 500 mg conventional oral tablet; 1.8 mcg/ml for a 650 mg extended-release oral tablet.
- The onset of paracetamol is within 1 hour.
- Distribution in the body is about 1L/kg.
- It is protein bound for 10 to 25%.
- Metabolism occurs primarily in the liver through the microsomal enzyme systems. Acetaminophen conjugation in the liver is through the glucorinic/sulfuric acid systems.
- Metabolites from the synthesis of paracetamol are the following: N-acetyl-p-benzoquinoeimine and N-acetylimidoquinone. These toxic components are further broken down, together with glutathione, to safer components for elimination.
- The half-life elimination of acetaminophen differs per age group: 1.25-3 hours for adolescents; 2-5 hours for children; 4 hours for infants; 7 hours for neonates; and 2-3 hours for adults.
- Acetaminophen is primarily excreted in the urine as acetaminophen glucoronide with acetaminophen sulfate/mercaptate.
Acetaminophen Nursing Considerations
- The healthcare provider should consider all forms, sources and routes of administration of acetaminophen when calculating for the patient’s maximum dose and should not exceed 4 grams per day.
- For those with renal impairment, the glomerular filtration rate (GFR) is the basis for dose adjustments and are as follows:
- For GFR of more than or equal to 50 ml/min: No adjustments needed
- For GFR of 10-50 ml/min: Administration time should be every 6 hours
- For GFR of less than 10 ml/min: Administration time should be every 8 hours
- For patients on continuous renal replacement therapy: Administration time should be every 6 hours.
For those with liver issues, extreme caution is warranted and avoid usage as much as possible. If not possible, paracetamol doses should be limited for short-term use and doses should not exceed 2 grams per day.
The pediatric indication of paracetamol is the same with adults which is for use as analgesic and antipyretic. However, dosing differs and they are as follows:
- Weight-based calculation dosing (oral-based)
- For neonates 28-31 weeks of gestation: 10-15 mg/kg/dose per mouth every 12 hours as needed; An initial loading dose of 20 mg/kg per mouth may be given. Doses should not exceed the 40 mg/kg/day or a 48-hour consecutive maximum doses.
- For neonates 32-37 weeks of gestation: 10-15 mg/kg/dose per mouth every 8 hours as needed; An initial loading dose of 20 mg/kg per mouth may be given. Doses should not exceed the 60 mg/kg/day or a 48-hour consecutive maximum doses.
- For neonates 0-9 days: 10-15 mg/kg/dose per mouth every 6-8 hours as needed; An initial loading dose of 20 mg/kg per mouth may be given. Doses should not exceed the 60 mg/kg/day or a 48-hour consecutive maximum doses.
- For neonates 10-29 days: 10-15 mg/kg/dose per mouth every 4-8 hours as needed; An initial loading dose of 20 mg/kg per mouth may be given. Doses should not exceed the 90 mg/kg/day or a 48-hour consecutive maximum doses.
- For infants: 10-15 mg/kg/dose per mouth every 4-6 hours as needed with doses not exceeding 15 mg/kg/dose or 75 mg/kg/day.
- For Children and adolescents below 60 kg: 10-15 mg/kg/dose per mouth every 4-6 hours as needed with doses not exceeding 15 mg/kg/dose or 1000 mg/dose whichever is less or 75 mg/kg/day or 4000 mg/day whichever is less.
2. Fixed dosing (oral based)
- For 6-12 years old: 325 to 650 mg per mouth taken every 4 to 6 hours as needed and should not exceed 3.25 grams per day. Four grams per day may be utilized but only under the supervision of a healthcare personnel.
- for 12 years and above:
- Regular strength: 325-650 mg per mouth taken every 4-6 hours as needed and should not exceed 3.25 g/day. Four grams per day may be given but only under the supervision of a healthcare worker.
- Extra strength: 1000 mg per mouth taken every 6 hours as needed and not exceeding 3 grams for a 24-hour period. 4 g/day may be used under guidance of a healthcare worker.
- Extended release: 1300 mg per mouth taken every 8 hours and should not exceed 3.9 grams/24 hours.
As with adults, the healthcare provider for the pediatric patient is expected to consider all forms, sources and routes of administration of acetaminophen when calculating for the patient’s maximum dose and should not exceed 4 grams per day in general.
Drug Interactions with Acetaminophen
- Acetaminophen and effects of other substances – Substances that manipulate the hepatic cytochome enzyme CYP2E1 may alter the breakdown of acetaminophen in the liver and may increase its hepatotoxic effects. Examples of which are certain fluoroquinolones (an antibiotic), other glucocorticoids, and anti-tuberculosis drugs to name a few. Ethanol and its hepatotoxic effects are apparent because excessive alcoholism can trigger this. However, ethanol per se also contributes in stopping the metabolism of paracetamol in the liver.
- Acetaminophen and anticoagulants – Long-term usage of acetaminophen with doses of 4 grams per day has been attributed to cause increases in some patient’s international normalized ratio (INR) who were otherwise treated with sodium warfarin as anti-coagulant. Despite of these, the correlation of short-term use of paracetamol who also takes sodium warfarin cannot be established and would need further investigation.
Adverse Effects of Acetaminophen
Associated adverse effects of acetaminophen may include:
- Angioedema, or the swelling under the skin
- Pruritic, maculopapular rash
- Hyperammonemia, or the abnormal elevation of serum ammonia
- Steven-Johnson Syndrome – a syndrome associated with severe reaction to medications characterized by painful blisters all over the body
- Toxic epidermal necrolysis – a life-threatening condition characterized by the blistering and peeling of the skin due to a reaction to medications
- Gastrointestinal hemorrhage
- Laryngeal edema
- Agranulocytosis, or the severe reduction of the bodies’ neutrophils
- Leukopenia, or the excessive reduction of white blood cells in the body
- Pancytopenia, or the severe reduction of the three types of blood cells namely the erythrocytes, leukocytes and thrombocytes.
- Thrombocytopenia, or the excessive reduction of thrombocytes.
- Thrombocytopenic purpura – the decreased number of platelets in the body. It is characterized by easy bruising, internal bleeding, etc
- Liver failure
- Pneumonitis, or the general inflammation of lung tissue.
- Anaphylaxis, or the severe and potentially mortal allergic reaction.
Contraindications of Acetaminophen
Acetaminophen is contraindicated to those with:
- Hypersensitivity to the drug
- Severe and active liver disease
Caution should be exercised in administering acetaminophen because of the following:
- Reports of hypersensitivity and anaphylactic reactions
- Multiple dosage forms and doses readily available
- Patients with active liver disease, hepatic issues
- Higher risks of hepatotoxicity to patients on long-term use of high doses of paracetamol, or those taking more than one paracetamol-containing product
- Patients with severe renal impairment for it would necessitate dose adjustments
- Patients who take alcoholic drinks three or more in a day may have an increased risk for liver disease.
- Patients diagnosed with G6PD deficiency
- Patients with long-term malnutrition
- Presence of risk to rare, severe and serious skin conditions such as Steven-Johnson Syndrome, toxic epidermal necrolysis, and acute generalized exanthematous pustulosis. These conditions may start to present as skin redness, blisters, and rash formation.
- Limit dosage of paracetamol from all sources and routes to less than four grams per day
Pregnancy and Acetaminophen
The following are the pharmacology of Acetaminophen during pregnancy and lactating mothers:
- Acetaminophen has been proven to cross the placenta. Due to this, acetaminophen can be detected in the fetus’s cord blood, newborn’s serum and urine immediately after delivery.
- There were no reports of increased risk for teratogenic effects while taking acetaminophen during pregnancy.
- There were no reports of increased risk of miscarriage or still birth when used on normal dosages during pregnancy. However, increased fetal death and spontaneous abortion may be observed if treatment is delayed for maternal over dose.
- Wheezing and asthma has been noted in early childhood for mothers who frequently use paracetamol during pregnancy.
- Paracetamol is excreted in breast milk. Generally, breastfeeding is acceptable if the relative infant dose (RID) is <10%. However, RIDs of >25% are contraindicated for breastfeeding.
Acetaminophen Poisoning and Its Management
Acetaminophen poisoning is the over dosage of the over-the-counter and common drug acetaminophen or paracetamol. Specifically, it occurs when the patient exceeds the recommended maximum dose of four grams, or three grams for those with liver disease.
Causes of Acetaminophen Poisoning
Paracetamol overdose occurs when there is:
- Intentional overdose, (e.g., suicide attempt)
- Accidental overdose, (e.g., unsupervised children)
- Taking and combining medications that contain paracetamol. (Acetaminophen is found in more combination products when compared to any other drug.)
- Toxicity levels may happen even on recommended doses, especially for patients with liver disease.
Risk Factors of Acetaminophen Poisoning
Some factors increase paracetamol poisoning risks and are as follows:
- Age: those between 15-24 years old or 40 years old or older (Severe side effects are prevalent for those 40 years old and above)
- Sex: Female
- Suicidal behavior
Symptoms of Acetaminophen Poisoning
Initial manifestations include:
- Excessive sweating
- Pale skin
- Symptoms of liver failure such as – Anorexia, nausea, vomiting, malaise, abdominal pain, pale skin, excessive sweating, jaundice, confusion, stupor
Diagnosis of Acetaminophen Poisoning
Diagnosing paracetamol or acetaminophen overdose includes the following:
- Blood tests – These are utilized to determine the serum level of paracetamol and the liver function of the patient. (e.g., liver enzyme tests, coagulation tests).
- Rumack-Matthew Nomogram – An assessment test that determines the effect of paracetamol in the liver by measuring the serum levels against the initial time that the drug was ingested.
Treatment for Acetaminophen Poisoning
The management of aetaminophen overdose includes the following:
- Monitoring. For children with relatively low serum levels of paracetamol, home monitoring may be indicated.
- Activated charcoal. This is utilized and ingested by mouth so as to prevent the excess paracetamol from being absorbed through the gastrointestinal tract.
- N-acetylcysteine – For those with more severe or complicated paracetamol or acetaminophen overdose, parenteral administration of N-aetylcysteine, an amino acid, is the drug of choice and antidote to counteract its toxic effects.
Nursing Care Plan for Patients on Acetaminophen
Possible Nursing Diagnoses
- Risk for Impaired Liver Function
- Nausea and Vomiting secondary to acetaminophen poisoning
- Risk for Electrolyte Imbalance (Hypokalemia) secondary to acetaminophen poisoning
|Acetaminophen Nursing Interventions||Rationale|
|Assess the patient for signs and symptoms of fever or pain.||To confirm the indication for administering acetaminophen.|
|Check the patient’s allergy status.||Alternatives to acetaminophen should be considered in case of allergy.|
|Assess if the patient is pregnant or lactating.||Pregnant and breastfeeding women can continue taking their acetaminophen daily but will be closely monitored by their physician. It is also important to let the breastfeeding mother know that acetaminophen may be passed into breast milk.|
|Assess the patient’s ability to self-administer the medication.||To check for any potential problems with administration.|
To ensure that the right form of acetaminophen is given through the right route.
|Check the patient’s serum potassium levels. Check for current medications that include anticoagulants as these should be used cautiously with acetaminophen.||An increased risk of hypokalemia may occur when a patient consumes excessive amounts of acetaminophen. Caution is highly warranted as hypokalemia is greatly associated with dysrhythmia and heart failure. Acetaminophen may increase INR, which affects patients on anticoagulants such as warfarin.|
Nursing Planning and Intervention
|Acetaminophen Nursing Interventions||Rationale|
|Administer acetaminophen at the same time each day.||To ensure medicine compliance and lower the risk for pain to develop.|
|Advise the patient that acetaminophen or paracetamol can be taken with or without food.||Acetaminophen or paracetamol does not irritate the lining of the stomach, so it can be taken on an empty stomach.|
|Advise the patient to prevent drinking excessive amounts of alcohol while on acetaminophen.||Acetaminophen combined with excessive amounts of alcohol may cause hepatic damage.|
|Educate the patient about the action, indication, common side effects, and adverse reactions to note when taking acetaminophen. Instruct the patient on how to self-administer acetaminophen.||To inform the patient on the basics of acetaminophen, as well as to empower him/her to safely self-administer the medication.|
|Advise the patient to report any feeling of nausea or episode of vomiting.||Nausea and vomiting are signs and symptoms of acetaminophen poisoning.|
|Routinely check for the serum potassium level of the patient, especially if they are on loop diuretics.||Excessive acetaminophen can cause hypokalemia. The occurrence of hypokalemia is more likely if the patient is also on loop diuretic therapy.|
|Acetaminophen Nursing Interventions||Rationale|
|Ask the patient to repeat the information about acetaminophen, such as the right dose and the maximum dose per day.||To evaluate the effectiveness of health teaching on acetaminophen.|
|Monitor the patient’s serum electrolyte levels.||To ensure that the acetaminophen did not cause any electrolyte imbalance (particularly hypokalemia).|
|Monitor the patient’s response to acetaminophen.||To check if acetaminophen is effective or if another type of pain relief is needed.|
|Monitor for any symptoms of diarrhea or hepatic/ liver damage, and treat these as they appear.||Acetaminophen may cause diarrhea as well as hepatic damage.|
Ackley, B. J., Ladwig, G. B., Makic, M. B., Martinez-Kratz, M. R., & Zanotti, M. (2020). Nursing diagnoses handbook: An evidence-based guide to planning care. St. Louis, MO: Elsevier. Buy on Amazon
Gulanick, M., & Myers, J. L. (2017). Nursing care plans: Diagnoses, interventions, & outcomes. St. Louis, MO: Elsevier. Buy on Amazon
Ignatavicius, D. D., Workman, M. L., Rebar, C. R., & Heimgartner, N. M. (2018). Medical-surgical nursing: Concepts for interprofessional collaborative care. St. Louis, MO: Elsevier. Buy on Amazon
Silvestri, L. A. (2020). Saunders comprehensive review for the NCLEX-RN examination. St. Louis, MO: Elsevier. Buy on Amazon
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