Acenol

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Acenol

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Medically reviewed

Laura Arias

Last updated on 22/12/2025

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Acenol

What is Acenol?

Acenol is a pharmaceutical formulation containing paracetamol, a widely used active ingredient known for its analgesic and antipyretic properties. It is primarily utilized to manage mild to moderate pain and to reduce elevated body temperature.

Mechanism of Action

The active substance in Acenol works by inhibiting the production of prostaglandins in the central nervous system. Prostaglandins are lipid compounds that transmit pain signals and play a role in regulating the body's internal thermostat. By reducing the concentration of these compounds, the medication helps to increase the pain threshold and facilitate heat loss through the skin.

Therapeutic Use

Acenol is intended for the symptomatic relief of various types of discomfort, including:

  • Headaches and migraines
  • Muscle and joint pain
  • Neuralgia
  • Toothaches
  • Menstrual pain
  • Fever associated with colds, influenza, or other infections

Unlike non-steroidal anti-inflammatory drugs (NSAIDs), Acenol has very limited anti-inflammatory activity. However, it is often preferred for patients with sensitive stomachs or those who cannot tolerate traditional anti-inflammatory medications, as it generally has a lower risk of causing gastrointestinal irritation when used as directed.

Regulatory References

  1. WHO Model List of Essential Medicines - Paracetamol
  2. Acetaminophen (Paracetamol) Drug Information

What side effects are possible with Acenol?

Possible Side Effects and Safety Information

The safety profile of Acenol, which contains Paracetamol (Acetaminophen), is defined by potential adverse reactions that are classified by frequency and grouped according to the system or organ affected, as documented in official regulatory labeling.

Adverse effects reported in regulatory documents are generally considered Rare or Very Rare when the medicine is used at therapeutic doses. These documented effects fall into several System-Organ Classes (SOCs):

  • Hepato-biliary disorders: Abnormal hepatic function, hepatic failure, and hepatic necrosis are documented, though these serious reactions are primarily associated with exposure levels above the recommended dosage.
  • Skin and subcutaneous tissue disorders: Rare occurrences of rash and urticaria are noted. Extremely serious but Very Rare reactions include Severe Cutaneous Adverse Reactions (SCARs) such as Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN).
  • Blood and lymphatic system disorders: Changes in blood counts, such as thrombocytopenia and agranulocytosis, are reported as rare.
  • Immune system disorders: Hypersensitivity reactions and, in rare instances, severe potential for anaphylactic shock are noted.

Serious Safety Considerations officially prioritize the risk of hepatotoxicity (liver damage). This risk is increased by prolonged high-dose use of the medicine. Furthermore, safety constraints include specific cautions or contraindications for individuals with pre-existing conditions, particularly severe hepatic impairment or severe active liver disease. Caution is also specified for patients with renal impairment or conditions that may lead to glutathione deficiency.

Overdose and Emergency Response

Overdose and when to seek help

Immediate medical attention must be sought urgently in all cases of suspected Acenol overdose. This regulatory mandate applies even if the individual shows no initial symptoms or if symptoms are limited to mild discomfort, due to the established risk of severe, delayed liver damage. Contacting a Poison Control Center immediately is a required emergency action listed in government guidance.

Documented Overdose Manifestations and Outcomes

Initial signs of overdose, which may be present in the first 24 hours, often include non-specific symptoms such as nausea, vomiting, pallor, anorexia, and abdominal pain. The most serious outcome documented in official labeling is dose-dependent acute liver failure and hepatic necrosis. Severe poisoning can lead to systemic complications, including renal failure, encephalopathy, and ultimately death.

Antidote and Required Monitoring

Official documents confirm that the specific antidote for Acenol overdose is N-acetylcysteine (NAC). Regulatory guidance stresses that the maximum protective effect is achieved when NAC administration is initiated as soon as possible, ideally within the first eight hours of ingestion. To determine the necessity and duration of treatment, hospital monitoring is required, including the measurement of serum acetaminophen concentrations and continuous assessment of hepatic function (ALT, AST, and INR).

Population-Specific Considerations

Official labeling notes that the hazard of hepatotoxicity is increased in specific populations. Individuals with chronic alcohol consumption, those who are malnourished, or patients concurrently taking enzyme-inducing drugs are documented as being at greater risk of severe outcomes from an overdose.

Therapeutic Uses of Acenol

Acenol, which contains Paracetamol (Acetaminophen), is commonly used to provide supportive symptomatic relief across two key therapeutic domains where patients experience symptoms that may create noticeable physiological strain. The core therapeutic area for managing the symptoms of pain and fever is addressed in accordance with established clinical practice.


Management of Mild to Moderate Pain

This domain is applied to situations involving distressing symptoms related to physical discomfort, such as tension headaches, muscular aches, and discomfort from dental pain or period pain. It is commonly used across conditions presenting with episodic or fluctuating manifestations, including mild osteoarthritis and post-injury discomfort. In such situations, Acenol may assist in easing discomfort and helps patients cope more steadily with difficult episodes. Symptomatic assistance is often sought when symptoms interfere with routine activities. Quick Fact: Support for Acute Pain and Pyrexia


Easing of Fever and Systemic Discomfort

Acenol is applied across domains where additional symptomatic support is needed to address symptoms related to systemic imbalance, specifically the presence of an elevated body temperature (fever), often accompanying colds or flu. This relief is considered relevant in clinical settings that involve acute or unstable symptom patterns. Providing support for this domain assists with maintaining functional stability and helps ease the overall symptom load when fever and general body aches interfere with routine activities.


Key Indications (Symptom Categories)

Acenol is commonly used to help with acute or episodic manifestations such as headache, toothache, backache, and muscular discomfort. It is also a supportive measure applied in addressing fever and the systemic aches associated with common viral illnesses.

Eligibility and Restrictions for Use

The eligibility for Acenol (Paracetamol/Acetaminophen) is strictly defined by government regulatory documents, focusing on patient status and specific medical conditions. Use is contraindicated (absolutely prohibited) for two primary populations: those with a known hypersensitivity (allergy) to the active ingredient or its excipients, and patients with severe hepatic impairment or severe active liver disease [1.6].

Eligibility Constraints

Classification Population/Condition
Contraindicated Severe Hepatic Impairment / Severe Active Liver Disease
Contraindicated Known Hypersensitivity to Paracetamol
Conditional Use Severe Renal Impairment, Chronic Alcoholism, Chronic Malnutrition, Active Hepatic Disease [1.6]

Acenol is established for use in adults and older adults without specific differences in safety or efficacy. While generally available for pediatric use, some oral formulations are not recommended for children under 10 years of age [2.1]. During pregnancy, it can be used if clinically needed at the lowest effective dose for the shortest possible duration. It is generally considered compatible with breastfeeding at recommended doses [1.1].

What should I know about interactions with other medicines?

Interactions with other medicines and products

The interaction profile of Acenol (Paracetamol/Acetaminophen) highlights specific regulatory restrictions and co-administration requirements to manage safety risks, based on governmental prescribing information.

Documented Interaction Patterns

Classification Interacting Agents Official Interaction Outcome
Contraindicated Combination Other products containing Acetaminophen (Paracetamol) Prohibited due to the risk of severe liver damage from exceeding the maximum daily dose.
Pharmacodynamic Warfarin and other Coumarins Regular, prolonged daily use significantly enhances the anticoagulant effect, increasing the risk of bleeding.
Metabolic Enzyme Inducers (e.g., Carbamazepine, Rifampicin, Alcohol) Increases the risk of liver damage (hepatotoxicity) due to enhanced formation of a toxic metabolite.

Absorption and Timing Requirements

Substances that affect gastrointestinal motility or bind to medications can alter Acenol's absorption. Metoclopramide or Domperidone are documented to increase the speed of absorption. Conversely, Cholestyramine significantly reduces absorption; therefore, regulatory documents mandate separating the administration of Acenol by at least one hour before or four to six hours after Cholestyramine.

Population-Specific Notes

The co-administration of high-dose Acenol with Flucloxacillin carries a documented risk of High Anion Gap Metabolic Acidosis (HAGMA). This interaction risk is considered heightened in patients with underlying conditions causing glutathione deficiency, such as severe renal impairment, malnutrition, or chronic alcoholism.

Mechanism of Action

How Acenol Works — Mechanism of Action

Acenol (Paracetamol) acts almost entirely within the Central Nervous System (CNS) through distinct and complementary pharmacodynamic mechanisms, resulting in specific physiological changes. The action is determined by the molecule's unique interaction with key enzymes and receptors, engaging highly targeted pathway modulation.


Central Inhibition of Prostaglandin Mediators

This domain covers the drug's effect on enzyme activity, primarily targeting Cyclooxygenase (COX) enzymes within the hypothalamus and spinal cord. By limiting the formation of Prostaglandin E2 (PGE2) in the hypothalamus, the mechanism modulates the body's thermal set-point.


Neuromodulation via Endocannabinoid Pathways

Acenol's influence on nociceptive pathways involves a complex cascade where the parent drug is converted into an active metabolite (AM404) within the CNS. This metabolite modulates the Cannabinoid Receptor 1 (CB1) and the Transient Receptor Potential Vanilloid 1 (TRPV1) ion channel, influencing nociceptive signal transduction in the spinal cord.


Mechanistic Constraint: Lack of Peripheral Action

The drug's mechanism of COX inhibition is functionally constrained by high peroxide concentrations typically found in peripheral tissues, limiting its activity outside the CNS. This unique biochemical constraint limits its potency in peripheral tissues and results in minimal inhibition of processes such as platelet aggregation or peripheral anti-inflammatory cascades.

Dosage and Administration Information

How to use Acenol: Official Administration Guidelines

The administration of Acenol, which contains Paracetamol (Acetaminophen), is defined by specifications regarding approved methods of intake, precise dosage, and required timing for use.

Property Official Instructions (Label-Based)
Route of Administration The medicine is approved for Oral intake (tablet, solution), Intravenous (IV) Infusion, and Rectal use (suppository).
Dosing Schedule (Adults ge 50 kg) A standard single dose is 1000 mg (1 gram). Dosing must be scheduled every 4 to 6 hours as needed, with a minimum interval of 4 hours between doses.
Maximum Total Daily Dose The combined intake from all forms and routes (oral, IV, rectal) must not exceed 4000 mg (4 grams) in any 24-hour period.
Timing and Preparation Acenol may be taken with or without food. IV administration must be performed slowly as a 15-minute infusion. Modified-release oral forms must be swallowed whole.
Dose Adjustment Rules For individuals with severe renal impairment (CrCl le 30 mL/min), the minimum dosing interval must be extended to 6 hours or longer. For patients weighing less than 50 kg, dosing is weight-based (e.g., 15 mg/kg).

The official administration protocol for Acenol establishes standardized use by defining precise dose limits and minimum time intervals between doses. This structured approach defines how the medicine is physically prepared and delivered across its various forms (oral, IV, rectal), ensuring administration is consistent with established parameters.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Acenol

This overview summarizes the research that has been conducted on Acenol (Paracetamol), focusing on the types of studies available and the patterns those studies have described. This overview is drawn from official regulatory and peer-reviewed scientific sources.


Evidence for Acute Pain Relief (Analgesia)

Research exploring Acenol was evaluated in studies that have primarily utilized short-term randomized controlled trials (RCTs). These trials examined patient-reported experiences of pain intensity related to physical discomfort, such as headaches, dental pain, and post-operative discomfort.

Findings from numerous such studies reported measurements of patterns where differences were noted in pain intensity scores over short, defined time intervals. Some studies documented patterns where outcomes related to acute physical discomfort, especially episodic symptoms, described changes measured during the study periods. Research provides insight into these short-term changes.

However, the evidence is limited regarding the use of Acenol for long-term or chronic conditions. Research has explored the medicine in conditions like osteoarthritis and acute low back pain, but systematic reviews have reported that measured differences from comparison groups were often inconclusive in these specific areas. Long-term outcomes are not fully established, and data for extended use in many chronic conditions remain insufficient.


Evidence for Elevated Body Temperature (Antipyresis)

The evidence base for Acenol was evaluated in studies concerning elevated body temperature (fever) and relies heavily on short-term RCTs and subsequent meta-analyses. These studies monitored outcomes related to systemic or functional imbalance, specifically by measuring the rate and magnitude of changes in body temperature within defined short time frames.

The studies described patterns in the observed populations, where measurable changes in body temperature were frequently observed when compared to controls. Research provides insight into these short-term changes, as the effects were typically monitored over the acute phase.

Dedicated evidence exploring how patients report perceived discomfort or overall well-being related to fever remains limited. Additionally, because fever episodes are typically transient, the existing evidence contributes limited information regarding the clinical consequences of temperature management beyond the acute event. Comparative evidence against placebo is lacking in some regulatory summaries.


Evidence for Combination Use (Multimodal Analgesia)

Clinical trials and systematic reviews have examined Acenol as part of a combination regimen alongside other types of pain medication, especially in acute care settings. The studies monitored outcomes related to physical discomfort by measuring both pain intensity and the total amount of opioid medication used by patients following surgical procedures.

Findings describe patterns observed in these studies where the use of Acenol was linked to differences in the total consumption of opioid medication following surgical procedures. Studies explored how patients reported their experience and examined the influence on pain scores when the medicine was combined with other agents.

The evidence is limited regarding the clinical relevance of this combination approach for managing chronic, non-cancer pain, as most research focused on acute, short-term scenarios. Furthermore, subgroup findings are uncertain for some populations, such as older adults in multimodal pain management studies, as the results apply only to the specific populations and combination protocols studied in the trials.

Key Studies & References

  1. Paracetamol: A Review of Guideline Recommendations (Covers acute pain RCTs and general use)
  2. Opioid-Sparing Effects of IV Acetaminophen for Patients Undergoing Surgery (Covers multimodal use and opioid-sparing trials)
  3. Effect of Intravenous Paracetamol on Opioid Consumption in Multimodal Analgesia After Lumbar Disc Surgery: A Meta-Analysis of Randomized Controlled Trials
  4. Clinical Practice Guidelines : Acute pain management - The Royal Children's Hospital (RCH) (Used for context on pediatric/special population use)

Frequently Asked Questions (FAQ)

Common questions about Acenol (FAQ)


Q: How quickly does Acenol start to work after taking it?

Official information describes that the active substance in Acenol generally reaches its highest concentration in the blood plasma about 30 to 60 minutes after being taken by mouth. This period is often related to the time frame when the product's action is observed for pain or fever relief.

Q: Is Acenol known to be safe for long-term use?

Regulatory documents state that liver injury is associated with prolonged daily use of the drug, even when taken at recommended levels, in certain populations. For this reason, official product information often advises limiting use to the shortest duration necessary for treatment, especially when used in prolonged self-medication.

Q: Are there any common foods or drinks that interact with Acenol?

Regulatory warnings specifically caution against the consumption of alcohol, particularly three or more alcoholic drinks per day, as this can increase the risk of severe liver damage. Most official product information indicates that Acenol can generally be taken with or without food.

Q: How long does the effect of Acenol typically last?

The regulatory dosing schedule for Acenol in adults is typically established for intake every four to six hours as needed. This minimum time interval between doses provides an indication of the typical time frame considered for the medicine’s action.

Q: Does taking Acenol make you feel sleepy or drowsy?

Drowsiness or sleepiness is generally not listed as a common or frequently observed side effect in regulatory documents for single-ingredient formulations. The most prominent warnings in the official profile relate to liver safety.

Q: Is it possible to become dependent on Acenol?

Acenol is classified as a non-opioid analgesic. Unlike opioid medications, official regulatory documents do not list dependence, addiction, or withdrawal as known or expected risks associated with its use.

Q: What age group is Acenol generally approved for?

The drug is generally approved for use in adults and children age 12 and older. Products tailored for younger children are available, but their dosage is typically determined based on the child's weight or age, which makes adherence to product label instructions important.

Q: What are the signs of an allergic reaction to Acenol?

Regulatory documents describe signs of a severe allergic or hypersensitivity reaction, which may include swelling of the face, tongue, or throat, or a rash, hives, blisters, or redness/peeling of the skin. These symptoms require immediate medical attention.

Q: What happens if I accidentally take Acenol twice close together?

Taking doses too closely together can lead to exceeding the maximum daily dose, which significantly increases the risk of severe liver damage (hepatotoxicity). Regulatory documents state that medical help should be sought immediately in case of potential overdose, even if no obvious symptoms are present.

Q: Can Acenol be used by children?

Yes, Acenol is available for use in children, though the appropriate dosage and formulation depend on the child's age and weight. For this population, adherence to product label instructions or direction from a healthcare professional is noted.

Q: Can Acenol be taken with cold and flu medicine?

Official instructions prohibit taking Acenol with any other medicine that contains acetaminophen (Paracetamol). Because many cold, flu, and sinus products contain this ingredient, all labels must be thoroughly checked to prevent accidental overdose and avoid severe liver damage.

Q: How is Acenol eliminated from the body?

Regulatory data on the medicine’s processing indicate that the active ingredient in Acenol is predominantly broken down (metabolized) in the liver. It is then removed from the body primarily through the urine.

Q: What is the chemical class of Acenol?

The active ingredient in Acenol, Paracetamol (Acetaminophen), belongs to the chemical class known as p-aminophenol derivatives. It is classified pharmacologically as a non-opioid medicine for pain and fever.

Q: Is Acenol known to interact with herbal supplements?

While regulatory labels do not list every herbal supplement, government-affiliated resources note that a potential risk exists when taking Acenol with certain liver-toxic herbs. Theoretically, this combination could enhance the existing risk of liver damage associated with Acenol use.

Q: Is Acenol available in a liquid or chewable form?

Yes, Acenol and its generic counterparts are available in multiple forms to suit different needs. These formulations include liquid suspensions and certain brands are manufactured as chewable tablets or dissolvable powders.

Q: Can Acenol cause stomach irritation or heartburn?

Official regulatory warnings for Acenol primarily focus on the risk of liver damage and do not routinely include warnings for stomach bleeding or severe irritation. Unlike drugs such as NSAIDs, gastrointestinal side effects are not commonly documented.

Q: What is the typical duration of treatment with Acenol?

For self-medication of pain, official product information typically recommends use for no more than 10 days in adults. For self-medication of fever, use is usually limited to no more than 3 days, unless use beyond these timeframes is directed by a healthcare professional.

Q: Why are people with specific heart conditions advised against Acenol?

Acenol does not carry the same cardiovascular risk warnings as the class of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs). Government-affiliated professional advisories often note Acenol as a choice for pain management for patients with cardiovascular issues, based on its distinct mechanism of action.

Q: Why do official documents describe Acenol’s use conditions as non-directive?

The language in official regulatory documents is non-directive because governmental regulations require drug labeling to be purely factual. The text must describe the drug's properties and approved use conditions without offering personalized medical advice or encouraging its use.

Q: Are there any warnings about driving while taking Acenol?

Official warnings about driving ability are usually associated with medications that cause prominent sedation, dizziness, or confusion. Acenol's regulatory profile does not typically include a specific warning about impairment of the ability to drive or operate machinery.

Q: Can people with high blood pressure use Acenol?

High blood pressure is not typically listed as a contraindication in Acenol's regulatory information. Professional advisory notes often note Acenol as a choice for pain relief for patients with cardiovascular issues, unlike some other classes of pain relievers.

Q: What are the most common things people use Acenol for?

Research and regulatory documents show Acenol is most commonly used for relief from acute discomfort. This includes pain from various sources such as headaches, dental pain, muscle aches, and general post-operative discomfort, as well as reducing fever.

Q: What is the main difference between Acenol and Ibuprofen?

The main difference lies in their mechanism of action: Acenol is primarily a central analgesic and antipyretic. Unlike Ibuprofen (an NSAID), Acenol is structurally limited and therefore lacks significant anti-inflammatory action in the body's peripheral tissues at standard doses.

Q: Can Acenol change the results of blood tests?

Official documents report rare changes in blood counts, such as thrombocytopenia. Furthermore, the medicine's effects on the liver may affect the results of liver function tests.

Q: What happens if I take Acenol past its expiration date?

Regulatory documents specify that Acenol should be used by the expiration date and that expired product should be properly disposed of. Taking expired medicine may result in reduced effectiveness or, rarely, the potential for altered chemical properties.

Q: Are there any known drug interactions with common anti-depressants and Acenol?

While official labels cannot list every single medication, government-affiliated drug interaction databases have examined co-administration with antidepressants. They note that interactions with certain types of antidepressants are generally considered minor to moderate.

How should Acenol be stored and disposed of?

How to Store and Dispose of Acenol (Paracetamol/Acetaminophen)

Storage and disposal requirements for Acenol are governed by regulatory guidelines to ensure product stability and safety.

Storage Requirements

Formulation Temperature and Protection Stability and Handling
Oral Forms Store at controlled room temperature (20 C to 25 C) and protect from moisture and light. Keep container tightly closed and use by the expiration date.
IV Solution Store at 20 C to 25 C; must not be frozen. Discard unused solution immediately after use.

All forms of Acenol must be kept out of the sight and reach of children as a safety precaution against accidental ingestion.

Disposal Instructions

Regulatory documents specify that unused or expired Acenol must be handled according to local pharmaceutical waste regulations. The product must not be disposed of via wastewater or household trash but should be returned to a collection point or pharmacist.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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