Acetaminophen 500mg E/s Caplets
WARNING: Liver problems have happened with the use of acetaminophen. Sometimes, this has led to a liver transplant or death. Most of the time, liver problems happened in people taking more than 4,000 mg (milligrams) of acetaminophen in a day. People were also often taking more than 1 drug that had acetaminophen in it. If you have questions, talk with your doctor. @ COMMON USES: It is used to ease pain and fever.
Drug Class
Analgesic, Antipyretic
Pharmacologic Class
Para-aminophenol derivative
Pregnancy Category
Category B
FDA Approved
Jan 1970
DEA Schedule
Not Controlled
Overview
What is this medicine?
Acetaminophen is a common medicine used to relieve pain and reduce fever. It works by affecting how your brain senses pain and controls body temperature.
How to Use This Medicine
Taking Your Medication
To use this medication correctly, follow your doctor's instructions and read all the information provided. You can take this medication with or without food.
Storing and Disposing of Your Medication
Keep your medication at room temperature, avoiding refrigeration and freezing. Store it in its original container, protected from light, with the lid tightly closed. Choose a dry location, such as a closet or drawer, and avoid storing it in the bathroom.
Missing a Dose
If you take this medication regularly and miss a dose, take it as soon as you remember. However, if it's close to the time for your next dose, skip the missed dose and resume your regular schedule. Do not take two doses at the same time or take extra doses. If you take this medication as needed, follow your doctor's instructions and do not take it more frequently than recommended.
To use this medication correctly, follow your doctor's instructions and read all the information provided. You can take this medication with or without food.
Storing and Disposing of Your Medication
Keep your medication at room temperature, avoiding refrigeration and freezing. Store it in its original container, protected from light, with the lid tightly closed. Choose a dry location, such as a closet or drawer, and avoid storing it in the bathroom.
Missing a Dose
If you take this medication regularly and miss a dose, take it as soon as you remember. However, if it's close to the time for your next dose, skip the missed dose and resume your regular schedule. Do not take two doses at the same time or take extra doses. If you take this medication as needed, follow your doctor's instructions and do not take it more frequently than recommended.
Lifestyle & Tips
- Do not take more than the recommended dose, as this can cause serious liver damage.
- Be aware of other medications (prescription or over-the-counter) that may also contain acetaminophen to avoid accidental overdose.
- Limit or avoid alcohol consumption while taking acetaminophen, especially if you take it regularly, due to increased risk of liver damage.
Available Forms & Alternatives
Available Strengths:
- Acetaminophen 120mg Suppositories
- Acetaminophen 650mg Suppositories
- Acetaminophen 500mg Tablets
- Acetaminophen Child 160mg/5ml Susp
- Acetaminophen 500mg X/s Tablets
- Acetaminophen 500mg E/s Caplets
- Acetaminophen 160mg/5ml Solution
- Acetaminophen 325mg Tablets
- Acetaminophen 10mg/ml Inj, 100ml
- Acetaminophen 160mg/5ml Liquid
- Acetaminophen 500mg E/s Tablets
- Acetaminophen Child 160mg/5ml Susp
- Acetaminophen Infant 160mg/5ml Susp
- Acetaminophen 650mg ER Tablets
Dosing & Administration
Adult Dosing
Standard Dose:
500 mg to 1000 mg orally every 4 to 6 hours as needed
Dose Range:
500 - 1000 mg
Condition-Specific Dosing:
Maximum Daily Dose:
4000 mg in 24 hours (some sources recommend 3000 mg for chronic use or certain populations)
Pediatric Dosing
Neonatal:
Not established (use specific pediatric formulations and dosing)
Infant:
Not established (use specific pediatric formulations and dosing)
Child:
For children 12 years and older: 500 mg to 1000 mg orally every 4 to 6 hours as needed. Maximum 4000 mg in 24 hours. For children under 12, weight-based dosing (10-15 mg/kg per dose) with appropriate formulations is required, 500mg caplets are generally not suitable for younger children.
Adolescent:
500 mg to 1000 mg orally every 4 to 6 hours as needed. Maximum 4000 mg in 24 hours.
Dose Adjustments
Renal Impairment:
Mild:
No adjustment needed
Moderate:
No adjustment needed
Severe:
CrCl < 30 mL/min: Extend dosing interval to every 6-8 hours. Consult physician.
Dialysis:
Acetaminophen is dialyzable. Supplemental dose may be needed after hemodialysis. Consult physician.
Hepatic Impairment:
Mild:
Use with caution, consider reduced maximum daily dose (e.g., 2000 mg/day).
Moderate:
Use with extreme caution, significantly reduced dose (e.g., 2000 mg/day or less) or avoid. Consult physician.
Severe:
Contraindicated due to risk of hepatotoxicity.
Pharmacology
Mechanism of Action
Acetaminophen (paracetamol) is thought to produce analgesia by inhibiting prostaglandin synthesis, primarily in the central nervous system (CNS), and by a central action involving serotonergic descending pathways. Its antipyretic effect is produced by inhibition of the hypothalamic heat-regulating center.
Pharmacokinetics
Absorption:
Bioavailability:
60-90%
Tmax:
0.5-2 hours (oral)
FoodEffect:
Food may delay Tmax but does not significantly affect the extent of absorption.
Distribution:
Vd:
0.9 L/kg
ProteinBinding:
10-25% (at therapeutic concentrations)
CnssPenetration:
Limited (sufficient for central effects)
Elimination:
HalfLife:
1.5-3 hours (prolonged in liver disease or overdose)
Clearance:
Not available (highly variable)
ExcretionRoute:
Renal (primarily as glucuronide and sulfate conjugates, <5% as unchanged drug)
Unchanged:
<5%
Pharmacodynamics
OnsetOfAction:
30-60 minutes
PeakEffect:
1-2 hours
DurationOfAction:
4-6 hours
Safety & Warnings
BLACK BOX WARNING
Severe Liver Damage: Acetaminophen has been associated with cases of acute liver failure, sometimes resulting in liver transplant or death. Most cases of liver injury are associated with the use of acetaminophen at doses that exceed 4000 mg per day, and often involve more than one acetaminophen-containing product. Serious Skin Reactions: Acetaminophen has been associated with rare, but serious skin reactions that can be fatal, including Stevens-Johnson Syndrome (SJS), toxic epidermal necrolysis (TEN), and acute generalized exanthematous pustulosis (AGEP). These reactions can occur without warning. Discontinue acetaminophen at the first appearance of skin rash or any other sign of hypersensitivity.
Side Effects
Urgent Side Effects: Seek Medical Attention Immediately
Although rare, some individuals may experience severe and potentially life-threatening side effects while taking this medication. If you encounter any of the following symptoms, contact your doctor or seek medical help right away:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin (with or without fever)
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Note: In rare cases, allergic reactions can be life-threatening.
Signs of liver problems, including:
+ Dark urine
+ Tiredness
+ Decreased appetite
+ Upset stomach or stomach pain
+ Light-colored stools
+ Vomiting
+ Yellow skin or eyes
Difficulty urinating or changes in urine output
Severe skin reaction (Stevens-Johnson syndrome/toxic epidermal necrolysis), characterized by:
+ Red, swollen, blistered, or peeling skin (with or without fever)
+ Red or irritated eyes
+ Sores in the mouth, throat, nose, or eyes
Note: This condition can cause severe health problems that may be permanent and, in some cases, fatal.
Other Possible Side Effects
As with any medication, side effects can occur. While many people experience no side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other unusual symptoms, contact your doctor for guidance:
Upset stomach or vomiting
Trouble sleeping
Headache
Constipation
This list is not exhaustive, and you may experience other side effects not mentioned here. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Although rare, some individuals may experience severe and potentially life-threatening side effects while taking this medication. If you encounter any of the following symptoms, contact your doctor or seek medical help right away:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin (with or without fever)
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Note: In rare cases, allergic reactions can be life-threatening.
Signs of liver problems, including:
+ Dark urine
+ Tiredness
+ Decreased appetite
+ Upset stomach or stomach pain
+ Light-colored stools
+ Vomiting
+ Yellow skin or eyes
Difficulty urinating or changes in urine output
Severe skin reaction (Stevens-Johnson syndrome/toxic epidermal necrolysis), characterized by:
+ Red, swollen, blistered, or peeling skin (with or without fever)
+ Red or irritated eyes
+ Sores in the mouth, throat, nose, or eyes
Note: This condition can cause severe health problems that may be permanent and, in some cases, fatal.
Other Possible Side Effects
As with any medication, side effects can occur. While many people experience no side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other unusual symptoms, contact your doctor for guidance:
Upset stomach or vomiting
Trouble sleeping
Headache
Constipation
This list is not exhaustive, and you may experience other side effects not mentioned here. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Seek Immediate Medical Attention If You Experience:
- Yellowing of skin or eyes (jaundice)
- Dark urine
- Pale stools
- Persistent nausea or vomiting
- Severe stomach pain
- Unusual tiredness or weakness
- Skin rash, blistering, or peeling
- Swelling of the face, lips, tongue, or throat
- Difficulty breathing
Before Using This Medicine
Before Taking This Medication: Important Information to Share with Your Doctor
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, any of its components, or other substances, such as foods or drugs. Be sure to describe the symptoms you experienced as a result of the allergy.
If you have liver disease, as this may affect your ability to take this medication.
This list is not exhaustive, and it is crucial to discuss all your medications (including prescription and over-the-counter drugs, natural products, and vitamins) and health conditions with your doctor and pharmacist. They will help determine if it is safe for you to take this medication in conjunction with your other medications and health issues.
Remember, do not start, stop, or adjust the dosage of any medication without first consulting your doctor to ensure your safety.
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, any of its components, or other substances, such as foods or drugs. Be sure to describe the symptoms you experienced as a result of the allergy.
If you have liver disease, as this may affect your ability to take this medication.
This list is not exhaustive, and it is crucial to discuss all your medications (including prescription and over-the-counter drugs, natural products, and vitamins) and health conditions with your doctor and pharmacist. They will help determine if it is safe for you to take this medication in conjunction with your other medications and health issues.
Remember, do not start, stop, or adjust the dosage of any medication without first consulting your doctor to ensure your safety.
Precautions & Cautions
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication.
To avoid potential liver problems, be cautious not to take other products that contain acetaminophen. Carefully check the labels of all medications and supplements to ensure you are not exceeding the recommended daily intake of acetaminophen.
Follow the dosage instructions precisely, and do not exceed the maximum daily dose of acetaminophen as directed. The recommended daily limit is 4,000 milligrams (mg) for some individuals, as advised by their doctor. However, certain individuals, such as those with liver problems or children, may require a lower dose. If you are unsure about the safe amount of acetaminophen for your specific situation, consult your doctor or pharmacist. If you accidentally take too much acetaminophen in a day, contact your doctor immediately, even if you feel fine.
Before consuming alcohol, discuss the potential risks with your doctor. Additionally, this medication may interfere with certain laboratory tests, so it is crucial to inform all your healthcare providers and laboratory personnel that you are taking this drug.
When administering this medication to children, note that different brands may have varying dosage recommendations. Therefore, consult your doctor before giving this medication to a child to ensure the correct dose.
If you are pregnant, planning to become pregnant, or breastfeeding, inform your doctor. You and your doctor will need to discuss the potential benefits and risks of this medication to both you and your baby.
To avoid potential liver problems, be cautious not to take other products that contain acetaminophen. Carefully check the labels of all medications and supplements to ensure you are not exceeding the recommended daily intake of acetaminophen.
Follow the dosage instructions precisely, and do not exceed the maximum daily dose of acetaminophen as directed. The recommended daily limit is 4,000 milligrams (mg) for some individuals, as advised by their doctor. However, certain individuals, such as those with liver problems or children, may require a lower dose. If you are unsure about the safe amount of acetaminophen for your specific situation, consult your doctor or pharmacist. If you accidentally take too much acetaminophen in a day, contact your doctor immediately, even if you feel fine.
Before consuming alcohol, discuss the potential risks with your doctor. Additionally, this medication may interfere with certain laboratory tests, so it is crucial to inform all your healthcare providers and laboratory personnel that you are taking this drug.
When administering this medication to children, note that different brands may have varying dosage recommendations. Therefore, consult your doctor before giving this medication to a child to ensure the correct dose.
If you are pregnant, planning to become pregnant, or breastfeeding, inform your doctor. You and your doctor will need to discuss the potential benefits and risks of this medication to both you and your baby.
Overdose Information
Overdose Symptoms:
- Nausea
- Vomiting
- Abdominal pain (especially upper right quadrant)
- Loss of appetite
- Sweating
- Confusion
- Jaundice (delayed onset)
- Liver failure (delayed onset, can be fatal)
What to Do:
If you suspect an overdose, seek immediate medical attention. Call 911 or Poison Control at 1-800-222-1222. Treatment may involve activated charcoal if caught early, and N-acetylcysteine (NAC) as an antidote.
Drug Interactions
Contraindicated Interactions
- Not applicable (no absolute contraindications other than hypersensitivity or severe active liver disease)
Major Interactions
- Alcohol (chronic heavy use increases risk of hepatotoxicity)
- Warfarin (may increase INR and bleeding risk with chronic high-dose acetaminophen use)
- Isoniazid (may increase risk of hepatotoxicity)
- Phenytoin, Carbamazepine, Rifampin, Phenobarbital (CYP inducers, may increase formation of toxic NAPQI metabolite)
Moderate Interactions
- Cholestyramine (reduces acetaminophen absorption if given concurrently)
- Lamotrigine (acetaminophen may reduce lamotrigine levels)
- Zidovudine (may increase risk of neutropenia)
Minor Interactions
- Oral contraceptives (may slightly increase acetaminophen clearance)
Monitoring
Baseline Monitoring
Liver function tests (ALT, AST, bilirubin)
Rationale: To assess baseline liver health, especially in patients with pre-existing liver disease or those at risk for hepatotoxicity.
Timing: Prior to initiation of chronic high-dose therapy or in patients with liver impairment.
Routine Monitoring
Liver function tests (ALT, AST)
Frequency: Periodically (e.g., every 6-12 months) for patients on chronic high-dose therapy, or as clinically indicated.
Target: Within normal limits
Action Threshold: Significant elevation (e.g., >3x ULN) warrants dose reduction or discontinuation and further investigation.
INR (International Normalized Ratio)
Frequency: More frequently for patients on warfarin, especially when initiating or discontinuing acetaminophen or changing dose.
Target: Therapeutic range for warfarin
Action Threshold: INR outside target range requires warfarin dose adjustment.
Symptom Monitoring
- Signs of liver damage (e.g., yellowing of skin/eyes (jaundice), dark urine, pale stools, persistent nausea/vomiting, abdominal pain, unusual tiredness)
- Signs of allergic reaction (e.g., rash, itching, swelling, severe dizziness, trouble breathing)
- Signs of serious skin reactions (e.g., blistering, peeling skin, red or purple rash spreading and causing blistering and peeling, especially on the face or body)
Special Patient Groups
Pregnancy
Acetaminophen is generally considered the analgesic of choice during pregnancy when medication is needed. It is classified as Pregnancy Category B.
Trimester-Specific Risks:
First Trimester:
Generally considered safe, no increased risk of major birth defects.
Second Trimester:
Generally considered safe.
Third Trimester:
Generally considered safe. Some studies have suggested a possible link to increased risk of ADHD-like symptoms in children with prolonged prenatal exposure, but more research is needed, and the clinical significance is uncertain. Benefits typically outweigh potential risks for short-term use.
Lactation
Acetaminophen is considered compatible with breastfeeding and is rated L1 (Safest) by Hale's classification. It is excreted into breast milk in small amounts that are generally not harmful to the infant.
Infant Risk:
Low risk. No adverse effects reported in breastfed infants.
Pediatric Use
Dosing must be carefully calculated based on weight (10-15 mg/kg per dose) and age. The 500mg caplet strength is typically too high for young children and should only be used in adolescents or children over 12 years old, or as directed by a healthcare professional for specific weight-based dosing. Always use appropriate pediatric formulations (liquid, chewable) for younger children.
Geriatric Use
No specific dose adjustment is typically required based on age alone. However, elderly patients may have reduced renal or hepatic function, which could necessitate dose adjustments or increased monitoring. They may also be more susceptible to adverse effects or drug interactions.
Clinical Information
Clinical Pearls
- Acetaminophen is often hidden in many combination cold, flu, and pain medications. Always check labels to avoid accidental overdose.
- The maximum daily dose of 4000 mg (4 grams) should not be exceeded. For chronic use or in patients with risk factors for liver disease, a lower maximum daily dose (e.g., 3000 mg or even 2000 mg) may be recommended.
- Alcohol consumption significantly increases the risk of acetaminophen-induced hepatotoxicity.
- N-acetylcysteine (NAC) is the antidote for acetaminophen overdose and is most effective when administered within 8-10 hours of ingestion.
Alternative Therapies
- Nonsteroidal Anti-inflammatory Drugs (NSAIDs) such as Ibuprofen, Naproxen, Aspirin (for pain and fever, with different side effect profiles)
- Topical analgesics (for localized pain)
- Non-pharmacological pain management (e.g., RICE therapy, physical therapy, heat/cold packs)
Cost & Coverage
Average Cost:
$5 - $20 per 100 tablets (generic)
Generic Available:
Yes
Insurance Coverage:
Tier 1 (Generic)
General Drug Facts
If your symptoms or health issues persist or worsen, it's essential to contact your doctor for further guidance. To ensure your safety, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so be sure to check with your pharmacist for more information. If you have any questions or concerns about your medication, don't hesitate to reach out to your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek emergency medical attention. When seeking help, be prepared to provide details about the medication taken, the amount, and the time it happened.