Acetaminophen 650mg Suppositories
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 medicine used to relieve pain and reduce fever. This suppository form is inserted into the rectum, which can be helpful if you can't take medicine by mouth, for example, due to nausea or vomiting.
How to Use This Medicine
Taking Your Medication Correctly
To use this medication safely and effectively, follow your doctor's instructions and read all the information provided.
Insert the suppository rectally.
Before and after handling the suppository, wash your hands thoroughly.
If the suppository is soft, you can chill it in the refrigerator or run it under cold water to firm it up.
To use the suppository, remove the foil wrapper and wet the suppository before inserting it into the rectum with gentle pressure, pointed end first. Avoid excessive handling.
Storing and Disposing of Your Medication
Store the medication at room temperature, protected from light and in a dry place. Do not store it in a bathroom.
Do not freeze the medication. Some brands may require refrigeration; check with your pharmacist or the package label for specific storage instructions.
* Keep all medications in a safe location, out of the reach of children and pets.
Missing a Dose
If you take this medication on a regular schedule 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 dosing schedule. Do not take two doses at the same time or take extra doses. If you take this medication as needed, do not take it more frequently than directed by your doctor.
To use this medication safely and effectively, follow your doctor's instructions and read all the information provided.
Insert the suppository rectally.
Before and after handling the suppository, wash your hands thoroughly.
If the suppository is soft, you can chill it in the refrigerator or run it under cold water to firm it up.
To use the suppository, remove the foil wrapper and wet the suppository before inserting it into the rectum with gentle pressure, pointed end first. Avoid excessive handling.
Storing and Disposing of Your Medication
Store the medication at room temperature, protected from light and in a dry place. Do not store it in a bathroom.
Do not freeze the medication. Some brands may require refrigeration; check with your pharmacist or the package label for specific storage instructions.
* Keep all medications in a safe location, out of the reach of children and pets.
Missing a Dose
If you take this medication on a regular schedule 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 dosing schedule. Do not take two doses at the same time or take extra doses. If you take this medication as needed, do not take it more frequently than directed by your doctor.
Lifestyle & Tips
- Do not take more than the recommended dose, as this can cause severe liver damage.
- Do not take with other medicines that contain acetaminophen (e.g., many cold, flu, or pain medications). Check labels carefully.
- Avoid or limit alcohol consumption while taking acetaminophen, especially if you drink 3 or more alcoholic beverages daily, as this increases the risk of liver damage.
- Store suppositories in a cool, dry place, or as directed on the package (some may require refrigeration).
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:
650 mg rectally every 4-6 hours as needed
Dose Range:
650 - 1000 mg
Condition-Specific Dosing:
maximumDailyDose:
Not to exceed 4000 mg (4g) in 24 hours for most adults; lower for chronic use or risk factors (e.g., 3000 mg)
Pediatric Dosing
Neonatal:
Not established (650mg strength)
Infant:
Not established (650mg strength)
Child:
Not established (650mg strength for young children; lower strengths used)
Adolescent:
Typically 650 mg rectally every 4-6 hours as needed, not to exceed 4000 mg in 24 hours. Dosing should be based on weight (10-15 mg/kg/dose) for younger adolescents, but 650mg is generally for those weighing >43 kg.
Dose Adjustments
Renal Impairment:
Mild:
No adjustment typically needed
Moderate:
Consider extending dosing interval to every 6-8 hours
Severe:
Consider extending dosing interval to every 8 hours
Dialysis:
Acetaminophen is dialyzable; supplemental dose may be needed post-dialysis, but generally follow severe impairment guidelines. Consult nephrologist.
Hepatic Impairment:
Mild:
Use with caution; consider reduced dose or extended interval
Moderate:
Contraindicated or use with extreme caution; significantly reduced dose and extended interval (e.g., 50% dose, every 8-12 hours) may be necessary. Avoid if possible.
Severe:
Contraindicated due to risk of hepatotoxicity
Pharmacology
Mechanism of Action
Acetaminophen is thought to produce analgesia by elevating the pain threshold and antipyresis through action on the hypothalamic heat-regulating center. Its exact mechanism is not fully understood but is believed to involve inhibition of prostaglandin synthesis, primarily in the central nervous system (CNS), and possibly through modulation of the endocannabinoid system or serotonergic pathways. It has minimal anti-inflammatory effects.
Pharmacokinetics
Absorption:
Bioavailability:
Variable, generally 50-60% (rectal route, lower than oral)
Tmax:
2-4 hours (rectal route, slower than oral)
FoodEffect:
Not applicable for rectal administration; absorption can be slower and less complete than oral.
Distribution:
Vd:
Approximately 0.9 L/kg
ProteinBinding:
10-25% (at therapeutic concentrations)
CnssPenetration:
Yes (readily crosses blood-brain barrier)
Elimination:
HalfLife:
2-3 hours (in adults with normal liver function)
Clearance:
Approximately 5 mL/min/kg
ExcretionRoute:
Renal (as glucuronide and sulfate conjugates, and a small amount of unchanged drug)
Unchanged:
Less than 5%
Pharmacodynamics
OnsetOfAction:
30-60 minutes (rectal)
PeakEffect:
2-4 hours (rectal)
DurationOfAction:
4-6 hours
Safety & Warnings
BLACK BOX WARNING
Risk of severe liver damage (hepatotoxicity) if more than 4,000 mg (4 grams) of acetaminophen is taken in 24 hours, or if taken with other acetaminophen-containing products, or if 3 or more alcoholic drinks are consumed daily while using this product. Risk of severe allergic reactions (e.g., Stevens-Johnson Syndrome, Toxic Epidermal Necrolysis, Acute Generalized Exanthematous Pustulosis) which can be fatal.
Side Effects
Serious Side Effects: Seek Medical Help Immediately
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 medical attention 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
Signs of liver problems, including:
+ Dark urine
+ Tiredness
+ Decreased appetite
+ Upset stomach or stomach pain
+ Light-colored stools
+ Vomiting
+ Yellow skin or eyes
Urination problems, such as:
+ Inability to pass urine
+ Changes in urine output
A 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 do not go away, 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 medical attention 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
Signs of liver problems, including:
+ Dark urine
+ Tiredness
+ Decreased appetite
+ Upset stomach or stomach pain
+ Light-colored stools
+ Vomiting
+ Yellow skin or eyes
Urination problems, such as:
+ Inability to pass urine
+ Changes in urine output
A 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 do not go away, 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:
- Signs of liver damage: yellowing of skin or eyes (jaundice), dark urine, clay-colored stools, severe nausea or vomiting, loss of appetite, unusual tiredness, pain in the upper right side of the stomach.
- Signs of allergic reaction: rash, hives, itching, swelling of the face, lips, tongue, or throat, difficulty breathing or swallowing.
- Signs of severe skin reactions: blistering, peeling, or red skin rash.
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 symptoms you experienced as a result of the allergy.
If you have liver disease, as this may affect the use of this medication.
This list is not exhaustive, and it is crucial to discuss all your health conditions and medications with your doctor. Provide your doctor and pharmacist with a comprehensive list of:
All prescription and over-the-counter (OTC) medications you are taking
Any natural products or vitamins you are using
* Your health problems, including any medical conditions or diseases
Before starting, stopping, or changing the dose of any medication, including this one, consult with your doctor to ensure your safety. It is vital to verify that it is safe to take this medication with all your other drugs and health conditions.
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 symptoms you experienced as a result of the allergy.
If you have liver disease, as this may affect the use of this medication.
This list is not exhaustive, and it is crucial to discuss all your health conditions and medications with your doctor. Provide your doctor and pharmacist with a comprehensive list of:
All prescription and over-the-counter (OTC) medications you are taking
Any natural products or vitamins you are using
* Your health problems, including any medical conditions or diseases
Before starting, stopping, or changing the dose of any medication, including this one, consult with your doctor to ensure your safety. It is vital to verify that it is safe to take this medication with all your other drugs and health conditions.
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 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 mg (milligrams) without consulting your doctor. Certain individuals, such as those with liver problems or children, may require lower doses. If you are unsure about the safe amount of acetaminophen for you, consult your doctor or pharmacist. If you accidentally take too much acetaminophen in a day, contact your doctor immediately, even if you feel well.
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. Always consult with 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. It is necessary 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 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 mg (milligrams) without consulting your doctor. Certain individuals, such as those with liver problems or children, may require lower doses. If you are unsure about the safe amount of acetaminophen for you, consult your doctor or pharmacist. If you accidentally take too much acetaminophen in a day, contact your doctor immediately, even if you feel well.
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. Always consult with 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. It is necessary to discuss the potential benefits and risks of this medication to both you and your baby.
Overdose Information
Overdose Symptoms:
- Nausea
- Vomiting
- Loss of appetite
- Abdominal pain (especially upper right quadrant)
- Sweating
- Extreme tiredness
- Confusion
- Jaundice (yellowing of skin or eyes)
- Dark urine
What to Do:
Seek immediate medical attention. Call 911 or Poison Control at 1-800-222-1222. Overdose can lead to severe, irreversible liver damage or death if not treated promptly.
Drug Interactions
Major Interactions
- Alcohol (chronic heavy use increases risk of hepatotoxicity)
- Isoniazid (increased risk of hepatotoxicity)
- Other hepatotoxic drugs (e.g., methotrexate, amiodarone, carbamazepine - increased risk of liver injury)
Moderate Interactions
- Warfarin (may enhance anticoagulant effect, especially with chronic high doses of acetaminophen)
- Cholestyramine (may reduce acetaminophen absorption if given concurrently, separate administration by several hours)
- Phenytoin, Carbamazepine, Phenobarbital, Rifampin (inducers of CYP2E1, may increase formation of toxic NAPQI metabolite, increasing hepatotoxicity risk)
- Lamotrigine (acetaminophen may reduce lamotrigine levels)
Minor Interactions
- Oral contraceptives (may slightly increase acetaminophen clearance)
Monitoring
Baseline Monitoring
Liver function tests (ALT, AST, bilirubin)
Rationale: To establish baseline liver health, especially in patients with pre-existing liver disease or risk factors for hepatotoxicity (e.g., chronic alcohol use, malnutrition).
Timing: Prior to initiating therapy if risk factors are present.
Routine Monitoring
Assessment of pain/fever relief
Frequency: As needed, based on patient symptoms
Target: Reduction in pain score or normalization of temperature
Action Threshold: Lack of efficacy may indicate need for alternative therapy or re-evaluation of diagnosis.
Signs/symptoms of hepatotoxicity (e.g., nausea, vomiting, abdominal pain, dark urine, jaundice)
Frequency: Daily, especially with high doses or prolonged use
Target: Absence of symptoms
Action Threshold: Presence of symptoms warrants immediate discontinuation and medical evaluation (e.g., LFTs, acetaminophen levels).
Symptom Monitoring
- Pain level
- Body temperature
- Nausea
- Vomiting
- Abdominal pain (especially upper right quadrant)
- Dark urine
- Jaundice (yellowing of skin or eyes)
- Fatigue
- Loss of appetite
Special Patient Groups
Pregnancy
Acetaminophen is generally considered the analgesic/antipyretic of choice during pregnancy when medically indicated, particularly for short-term use. However, recent studies suggest potential associations with neurodevelopmental outcomes with prolonged or high-dose use, warranting caution and use of the lowest effective dose for the shortest duration.
Trimester-Specific Risks:
First Trimester:
Generally considered low risk, but use with caution and only if clearly needed.
Second Trimester:
Generally considered low risk.
Third Trimester:
Generally considered low risk, but use with caution and only if clearly needed.
Lactation
Acetaminophen is considered compatible with breastfeeding. It is excreted into breast milk in small amounts that are generally not expected to cause adverse effects in breastfed infants.
Infant Risk:
Low risk (L1)
Pediatric Use
Dosing must be carefully calculated based on weight (10-15 mg/kg/dose) and age. The 650mg suppository strength is typically too high for young children and is generally reserved for adolescents or adults. Always use appropriate strength and formulation for pediatric patients.
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. Monitor for adverse effects and ensure adequate hydration.
Clinical Information
Clinical Pearls
- Rectal absorption of acetaminophen is slower and less complete than oral absorption, leading to a delayed onset and lower peak concentrations. This may be beneficial for sustained effect but less ideal for rapid pain relief.
- Suppositories are useful for patients who cannot tolerate oral medication (e.g., nausea, vomiting, dysphagia) or are NPO.
- Always confirm that no other acetaminophen-containing products are being taken concurrently to avoid accidental overdose.
- Educate patients on the signs of liver toxicity and the importance of not exceeding the maximum daily dose.
- For fever reduction, consider non-pharmacological interventions (e.g., cool compresses) in conjunction with acetaminophen.
Alternative Therapies
- Nonsteroidal Anti-inflammatory Drugs (NSAIDs) like ibuprofen or naproxen (oral, rectal, IV)
- Aspirin (oral, rectal)
- Opioid analgesics (for severe pain, various routes)
- Local anesthetics (e.g., lidocaine patches for localized pain)
Cost & Coverage
Average Cost:
Price range varies widely by pharmacy and quantity per suppository
Generic Available:
Yes
Insurance Coverage:
Generally Tier 1 (preferred generic) or Tier 2 (non-preferred generic) on most insurance formularies.
General Drug Facts
If your symptoms or health issues persist or worsen, it is 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 it is a good idea to check with your pharmacist for more information. If you have any questions or concerns about this medication, do not hesitate to 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 medical attention. When seeking help, be prepared to provide details about the medication taken, the amount, and the time it happened.