Panadol 500mg (acetaminophen) Tb
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
Not available
FDA Approved
Sep 1951
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 certain chemicals in your brain that are involved in pain and temperature regulation.
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, away from light, and in a dry place. Store it in its original container with the lid tightly closed. Do not refrigerate or freeze your medication, and avoid storing it in a 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 continue with 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, away from light, and in a dry place. Store it in its original container with the lid tightly closed. Do not refrigerate or freeze your medication, and avoid storing it in a 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 continue with 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.
- Do not take with other medicines that contain acetaminophen.
- Limit or avoid alcohol consumption while taking acetaminophen, especially if you drink 3 or more alcoholic drinks per day, due to increased risk of liver damage.
- Store at room temperature away from moisture and heat.
Available Forms & Alternatives
Dosing & Administration
Adult Dosing
Standard Dose:
500 mg to 1000 mg every 4-6 hours as needed
Dose Range:
500 - 1000 mg
Condition-Specific Dosing:
maximumDailyDose:
4000 mg in 24 hours (for OTC products, some professional guidelines recommend 3000 mg for chronic use)
Pediatric Dosing
Neonatal:
Not established (consult physician)
Infant:
10-15 mg/kg per dose every 4-6 hours as needed (max 5 doses in 24 hours)
Child:
10-15 mg/kg per dose every 4-6 hours as needed (max 5 doses in 24 hours, not to exceed 75 mg/kg/day or 4000 mg/day, whichever is less)
Adolescent:
10-15 mg/kg per dose every 4-6 hours as needed (max 5 doses in 24 hours, not to exceed 4000 mg/day)
Dose Adjustments
Renal Impairment:
Mild:
No adjustment needed
Moderate:
Consider increasing dosing interval to 6 hours
Severe:
Consider increasing dosing interval to 8 hours (CrCl < 10 mL/min)
Dialysis:
Acetaminophen is dialyzable; administer after dialysis session for patients on hemodialysis. Consider 8-hour interval.
Hepatic Impairment:
Mild:
Use with caution, consider reduced maximum daily dose (e.g., 2000-3000 mg/day)
Moderate:
Use with caution, consider reduced maximum daily dose (e.g., 2000 mg/day) and extended dosing interval
Severe:
Contraindicated in severe active liver disease
Pharmacology
Mechanism of Action
Acetaminophen is thought to produce analgesia by inhibiting prostaglandin synthesis primarily in the central nervous system (CNS) and to a lesser extent peripherally. It also acts on the hypothalamic heat-regulating center to produce antipyresis by vasodilation and increased peripheral blood flow, resulting in heat dissipation.
Pharmacokinetics
Absorption:
Bioavailability:
60-90%
Tmax:
0.5-2 hours (oral)
FoodEffect:
Food may delay absorption but does not significantly affect the extent of absorption.
Distribution:
Vd:
0.95 L/kg
ProteinBinding:
10-25% (at therapeutic concentrations)
CnssPenetration:
Yes
Elimination:
HalfLife:
1.5-3 hours (adults), 2-5 hours (neonates)
Clearance:
Not available
ExcretionRoute:
Renal (urine)
Unchanged:
2-5%
Pharmacodynamics
OnsetOfAction:
30-60 minutes
PeakEffect:
1-2 hours
DurationOfAction:
4-6 hours
Safety & Warnings
BLACK BOX WARNING
Risk of severe liver injury and serious allergic reactions. Acetaminophen can cause severe liver damage if you take more than 4,000 mg in 24 hours, or take with other acetaminophen-containing products, or drink 3 or more alcoholic drinks every day while using this product. Severe allergic reactions (e.g., Stevens-Johnson Syndrome, toxic epidermal necrolysis, acute generalized exanthematous pustulosis) can occur. Discontinue use and seek immediate medical attention if skin rash or other allergic reaction occurs.
Side Effects
Urgent Side Effects: Seek Medical Help Right Away
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek immediate medical attention:
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
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
Other Possible Side Effects
Like all medications, this drug can cause side effects. While many people may not experience any 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 symptoms that bother you or persist, contact your doctor:
Upset stomach or vomiting
Trouble sleeping
Headache
Constipation
Reporting Side Effects
This list is not exhaustive, and you may experience other side effects. 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 people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek immediate medical attention:
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
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
Other Possible Side Effects
Like all medications, this drug can cause side effects. While many people may not experience any 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 symptoms that bother you or persist, contact your doctor:
Upset stomach or vomiting
Trouble sleeping
Headache
Constipation
Reporting Side Effects
This list is not exhaustive, and you may experience other side effects. 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
- Nausea, vomiting, or loss of appetite that doesn't go away
- Pain in the upper right side of the stomach
- Unusual tiredness or weakness
- Rash, hives, itching, or swelling of the face, lips, tongue, or throat (signs of allergic reaction)
- Difficulty breathing or swallowing
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, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
If you have liver disease, as this may affect the safety and efficacy of the medication.
This list is not exhaustive, and it is crucial to discuss all your medications, health conditions, and concerns with your doctor. This includes:
All prescription and over-the-counter (OTC) medications you are taking
Any natural products or vitamins you are using
* Your complete medical history, including any health problems you have or have had in the past
To ensure your safety, do not start, stop, or change the dose of any medication without first consulting your doctor. It is vital to verify that it is safe to take this medication with all your other medications and health conditions. Your doctor and pharmacist will work together to determine the best course of treatment for you.
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
If you have liver disease, as this may affect the safety and efficacy of the medication.
This list is not exhaustive, and it is crucial to discuss all your medications, health conditions, and concerns with your doctor. This includes:
All prescription and over-the-counter (OTC) medications you are taking
Any natural products or vitamins you are using
* Your complete medical history, including any health problems you have or have had in the past
To ensure your safety, do not start, stop, or change the dose of any medication without first consulting your doctor. It is vital to verify that it is safe to take this medication with all your other medications and health conditions. Your doctor and pharmacist will work together to determine the best course of treatment for you.
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, do not take any other products that contain acetaminophen. Carefully check the labels of all medications and supplements to ensure you are not exceeding the recommended daily dose of acetaminophen.
Follow the dosage instructions precisely, and do not exceed the maximum daily dose of acetaminophen as directed. The recommended daily dose can vary, but it should not exceed 4,000 milligrams (mg) unless specifically instructed by your doctor. However, certain individuals, such as those with liver problems or children, may require lower doses. If you are unsure about the appropriate dose 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 are not experiencing any symptoms.
Before consuming alcohol, discuss the potential risks with your doctor. Additionally, be aware that this medication may interfere with certain laboratory tests. Therefore, it is crucial to inform all your healthcare providers and laboratory personnel that you are taking this medication.
When administering this medication to children, note that different brands may have varying dosage recommendations. Consult your doctor before giving this medication to a child to ensure the correct dose is used.
If you are pregnant, planning to become pregnant, or breastfeeding, inform your doctor. It is necessary to discuss the potential benefits and risks of taking this medication during these situations to make an informed decision about your care and the well-being of your baby.
To avoid potential liver problems, do not take any other products that contain acetaminophen. Carefully check the labels of all medications and supplements to ensure you are not exceeding the recommended daily dose of acetaminophen.
Follow the dosage instructions precisely, and do not exceed the maximum daily dose of acetaminophen as directed. The recommended daily dose can vary, but it should not exceed 4,000 milligrams (mg) unless specifically instructed by your doctor. However, certain individuals, such as those with liver problems or children, may require lower doses. If you are unsure about the appropriate dose 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 are not experiencing any symptoms.
Before consuming alcohol, discuss the potential risks with your doctor. Additionally, be aware that this medication may interfere with certain laboratory tests. Therefore, it is crucial to inform all your healthcare providers and laboratory personnel that you are taking this medication.
When administering this medication to children, note that different brands may have varying dosage recommendations. Consult your doctor before giving this medication to a child to ensure the correct dose is used.
If you are pregnant, planning to become pregnant, or breastfeeding, inform your doctor. It is necessary to discuss the potential benefits and risks of taking this medication during these situations to make an informed decision about your care and the well-being of your baby.
Overdose Information
Overdose Symptoms:
- Nausea
- Vomiting
- Loss of appetite
- Stomach pain
- Sweating
- Extreme tiredness
- Yellowing of the skin or eyes (jaundice)
- Dark urine
What to Do:
Seek immediate medical attention. Call 911 or Poison Control at 1-800-222-1222. Overdose can cause severe, irreversible liver damage and death if not treated promptly. N-acetylcysteine (NAC) is the antidote.
Drug Interactions
Major Interactions
- Alcohol (chronic heavy use - increased risk of hepatotoxicity)
- Isoniazid (increased risk of hepatotoxicity)
- Warfarin (increased INR, bleeding risk with chronic high-dose acetaminophen)
Moderate Interactions
- Carbamazepine (decreased acetaminophen efficacy, increased hepatotoxicity risk)
- Phenobarbital (decreased acetaminophen efficacy, increased hepatotoxicity risk)
- Phenytoin (decreased acetaminophen efficacy, increased hepatotoxicity risk)
- Rifampin (decreased acetaminophen efficacy, increased hepatotoxicity risk)
- Cholestyramine (decreased acetaminophen absorption)
- Lamotrigine (decreased lamotrigine levels)
Minor Interactions
- Oral contraceptives (may slightly decrease acetaminophen levels)
Monitoring
Baseline Monitoring
Medical history (especially liver disease, alcohol use)
Rationale: To identify risk factors for hepatotoxicity
Timing: Prior to initiation
Routine Monitoring
Liver function tests (ALT, AST, bilirubin)
Frequency: Not routinely recommended for short-term, therapeutic use in healthy individuals. Consider for chronic high-dose use, pre-existing liver disease, or concomitant hepatotoxic drugs.
Target: Within normal limits
Action Threshold: Significant elevation (e.g., >3x ULN) warrants dose reduction or discontinuation and investigation.
INR (for patients on warfarin)
Frequency: More frequent monitoring when initiating or discontinuing acetaminophen, or with changes in 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, dark urine, persistent nausea/vomiting, abdominal pain, unusual tiredness)
- Signs of allergic reaction (e.g., rash, itching, swelling, severe dizziness, trouble breathing)
- Signs of gastrointestinal bleeding (if combined with NSAIDs)
Special Patient Groups
Pregnancy
Generally considered safe for use during pregnancy at recommended doses for short-term pain and fever relief. It is often the preferred analgesic during pregnancy.
Trimester-Specific Risks:
First Trimester:
Low risk, widely used.
Second Trimester:
Low risk, widely used.
Third Trimester:
Low risk, widely used. Some observational studies have suggested a possible association with neurodevelopmental disorders in children with prolonged or high-dose exposure, but causality is not established, and the benefits of pain/fever control often outweigh theoretical risks. Use the lowest effective dose for the shortest duration.
Lactation
Considered compatible with breastfeeding. It is excreted into breast milk in small amounts, but adverse effects on breastfed infants are not expected at therapeutic doses.
Infant Risk:
L1 (Safest)
Pediatric Use
Dosing is weight-based (10-15 mg/kg per dose). Accurate measurement is crucial. Do not exceed 5 doses in 24 hours. Avoid combination products to prevent accidental overdose.
Geriatric Use
Generally safe at recommended doses. No specific dose adjustment is typically needed based on age alone, but consider reduced maximum daily dose (e.g., 3000 mg/day) in frail elderly or those with comorbidities (e.g., liver impairment, chronic alcohol use).
Clinical Information
Clinical Pearls
- Acetaminophen is not an anti-inflammatory drug like NSAIDs.
- It is the preferred analgesic/antipyretic for patients with bleeding disorders, peptic ulcers, or renal impairment where NSAIDs are contraindicated.
- Accidental overdose is common due to its presence in many combination cold, flu, and pain medications. Always check labels for acetaminophen content.
- N-acetylcysteine (NAC) is the antidote for acetaminophen overdose and is most effective when administered within 8 hours of ingestion.
Alternative Therapies
- Nonsteroidal Anti-inflammatory Drugs (NSAIDs) such as ibuprofen, naproxen, aspirin (for pain and fever, with anti-inflammatory effects)
- Topical analgesics (e.g., lidocaine patches, capsaicin cream)
- Non-pharmacological interventions (e.g., rest, ice/heat, massage, physical therapy)
Cost & Coverage
Average Cost:
$5 - $20 per 100 tablets (500mg)
Generic Available:
Yes
Insurance Coverage:
Tier 1 (Generic)
General Drug Facts
If your symptoms or health issues persist or worsen, it is essential to contact your doctor promptly. To ensure safe and effective treatment, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet; consult your pharmacist for more information. If you have any questions or concerns about this medication, discuss them with 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. Be prepared to provide detailed information about the overdose, including the medication taken, the amount, and the time it occurred.