Pacidol

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Medically reviewed

Marina Burgos

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 Pacidol

Quick Facts

Property Description
Active ingredient Acetaminophen (Paracetamol)
Form Solid oral forms, liquid suspensions
Pharmacological class Analgesic and Antipyretic
Common use Symptomatic relief of general discomfort and fever
Origin Synthetic organic compound

Pacidol: Identity, Type, and Pharmacological Classification

Pacidol is a commercially recognized medicine primarily classified as both an analgesic (pain reliever) and an antipyretic (fever reducer). It is categorized as a non-opioid analgesic and is widely available as an over-the-counter (OTC) medicine. It is globally recognized for fundamental pain and fever management. The medicine is available for the oral route of administration in standard solid oral forms, such as tablets, and in liquid preparations like oral solutions.

The Core Ingredient: Acetaminophen and p-aminophenol Derivative

The sole active ingredient in Pacidol is Acetaminophen, a compound internationally known by the name Paracetamol. This substance is a synthetic organic compound chemically classified as a p-aminophenol derivative. The singular composition of Pacidol—containing only Acetaminophen—provides a direct therapeutic focus on the properties of this specific agent.

General Therapeutic Purpose and Mechanism Focus

The general purpose of Pacidol is to provide symptomatic relief when experiencing generalized aches or an elevated temperature, such as discomfort associated with a common cold. Its action is centered on the central nervous system, influencing the body's internal systems responsible for regulating temperature and pain perception. This central mechanism effectively helps the body reduce fever and raises the threshold at which pain signals are perceived, without exhibiting the significant peripheral anti-inflammatory effects associated with other classes of pain relievers.

Regulatory References

  1. World Health Organization Model List of Essential Medicines

What side effects are possible with Pacidol?

Possible Side Effects and Safety Information

The official safety profile for Pacidol (Acetaminophen/Paracetamol) is structured to communicate adverse effects based on the affected System-Organ Classes (SOCs) and their regulatory frequency classifications. The most critical safety characteristic documented in governmental labeling is the potential for hepatotoxicity, or liver damage.

Adverse Reaction Scope

Classification Representative Adverse Effects (SOCs)
Rare Severe Skin Reactions (Stevens-Johnson Syndrome, Toxic Epidermal Necrolysis), which are rare but potentially fatal serious adverse reactions.
Common Skin rash, general hypersensitivity reactions, gastrointestinal discomfort, and certain hematological (blood) or renal abnormalities.

Serious adverse reactions explicitly listed in regulatory documents include Acute Liver Failure, which is the primary cause of serious liver injury and is often associated with exceeding the maximum dose or long-term use. Other affected organ systems include Blood and Lymphatic System Disorders and Renal and Urinary Disorders.

Safety-Related Restrictions

The regulatory labeling defines specific safety limitations. The medicine is contraindicated for use in individuals with severe hepatic impairment or severe active liver disease. The primary safety restriction is the prohibition against co-administration; Pacidol must not be used concurrently with any other product containing acetaminophen, as this significantly increases the risk of severe liver damage. Safety notes also advise caution for individuals who regularly consume alcohol, citing an increased risk of severe liver injury.

These official safety statements establish that while general adverse effects are typically common and non-serious, the risk profile is dominated by the potential for serious, dose-related hepatotoxicity.

Overdose and Emergency Response

Overdose and when to seek help

Overdose Presentations and Scope

An overdose of Pacidol is primarily characterized by life-threatening respiratory depression (slowed, shallow, or absent breathing) and severe Central Nervous System (CNS) depression, which can manifest as profound sedation, stupor, or coma. Other documented presentations include pinpoint pupils (miosis), flaccid skeletal muscles, cold and clammy skin, and circulatory depression. These signs require immediate medical attention as they can rapidly lead to respiratory failure, shock, and death.

When to Seek Immediate Medical Help

Immediate medical help is required in all cases of suspected overdose. Individuals must immediately call emergency services (e.g., 911) if the patient shows any signs of unusual difficulty waking up, unresponsiveness, slow or shallow breathing, or profound sleepiness.

Emergency Regulatory Actions

Official regulatory documents emphasize that prompt intervention is necessary. Key emergency actions include maintaining a patent airway, providing assisted or controlled ventilation, and administering a specific opioid antagonist, such as Naloxone, if available. Even if the effects are initially reversed, continuous monitoring is required, as respiratory and CNS depression may recur, especially with long-acting formulations.

Specific Overdose Risks

Accidental ingestion of even one dose by a child is considered a fatal event and requires urgent medical treatment. Overdose risk is also increased with long-acting formulations due to the prolonged absorption and higher total drug content, demanding extended observation in a medical setting.

Therapeutic Uses of Pacidol

What Pacidol Treats: Main Uses and Benefits

Pacidol is commonly used in situations involving certain distressing symptoms related to pain and fever. It is generally applied when symptoms create noticeable interference with daily stability, playing a role in managing symptoms during acute episodes. The medication's role in supportive symptom management for these common manifestations is widely recognized.


Alleviating Pain and Fever

This medication is relevant for easing mild to moderate pain that arises from common sources, such as tension headaches, muscle aches, and menstrual discomfort. It is also commonly used across conditions characterized by periods of heightened symptoms (fever), relevant in contexts involving symptoms related to systemic imbalance. Pacidol is used when groups of symptoms appear suddenly or fluctuate, and it contributes to easing the overall symptom load during periods of heightened symptoms. This focus on short-term symptomatic assistance offers relief that may help patients cope more steadily during difficult episodes.


Quick Facts on Therapeutic Benefit

Property Description
Symptom Scope Easing mild to moderate pain, including headaches and muscle aches.
Core Function Supports the management of symptoms related to systemic imbalance, primarily fever.
Contextual Use Applied in scenarios requiring short-term symptomatic assistance for acute or episodic discomfort.

Regulatory References

  1. NIH's StatPearls overview

Eligibility and Restrictions for Use

Official Eligibility and Prohibited Use

Pacidol (Acetaminophen) eligibility is strictly defined by regulatory criteria, governing who may use the medicine and who must not, according to labeling approved by health authorities. The official criteria categorize users based on absolute prohibitions and conditional restrictions.

Absolute Contraindications (Must Not Use)

Use of this medicine is prohibited for patients with a known hypersensitivity (allergy) to acetaminophen or any components of the formulation. It is also contraindicated in patients with severe active liver disease or severe hepatic impairment. Furthermore, the medicine must not be taken if the patient is using any other prescription or over-the-counter product containing acetaminophen, to prevent accidental overdose.

Conditional Use and Restrictions

Use requires caution and may necessitate a regulatory-defined lower maximum daily quantity in specific populations. These include patients with severe renal impairment, chronic alcoholism, chronic malnutrition, or low body weight (adults under 50 kg). Patients with mild to moderate hepatic impairment also fall under this restricted-use category.

Age and Physiological Status

Pacidol is generally approved for use in adults and adolescents, and no overall dose adjustment is required for older adults (geriatric population). For some oral forms, the medicine is not recommended for children below specific age thresholds. Use during pregnancy and lactation is permitted when clinically necessary, provided it is at the lowest effective dose for the shortest duration.

What should I know about interactions with other medicines?

Pacidol Interactions with other medicines and products

The official regulatory profile for Pacidol (Acetaminophen) is structured to address risks related to systemic exposure and pharmacodynamic potentiation. A key restriction stated in official labeling is the explicit prohibition against co-administration with any other medicinal product, prescription or nonprescription, that contains acetaminophen.

Clinically Significant Pharmacokinetic Interactions

The most severe documented interactions concern metabolic clearance and absorption. Co-administration with Warfarin or other Vitamin K Antagonists may potentiate the anticoagulant effect, resulting in a documented increase in the International Normalized Ratio (INR). This effect is most significant with prolonged use at daily doses of 2 g or more.

Exposure-altering agents such as Probenecid reduce the clearance of Pacidol, leading to increased plasma concentrations. Conversely, Cholestyramine reduces Pacidol absorption, requiring a mandatory timing-based separation of at least one hour between the two administrations.

Metabolism and Condition-Specific Risk

Medicines that function as Hepatic Enzyme Inducers (e.g., Carbamazepine, Phenytoin, Rifampin) increase the documented risk of the toxic metabolite formation. This risk is formally heightened in patients with pre-existing liver disease and those with chronic, heavy alcohol consumption (ge 3 drinks daily), as specified in regulatory warnings.

Mechanism of Action

The drug Pacidol exerts its primary pharmacodynamic effects through multiple, complex mechanisms, predominantly targeting central nervous system (CNS) pathways, resulting in an altered physiological response profile.

Modulating Central Prostaglandin Synthesis

This domain involves enzyme-mediated signaling within the CNS. Pacidol weakly inhibits the cyclooxygenase (COX) pathway, leading to a reduction in the synthesis of prostaglandins—key mediators that increase body temperature and sensitize nerve endings. This action reduces prostaglandin synthesis, consequently altering the local signaling environment.

Engaging Serotonergic and Cannabinoid Systems

Pacidol modulates key pathways by affecting several central neurotransmitter systems. It may activate descending serotonergic pathways and can influence the cannabinoid system through its active metabolite. This metabolite inhibits the reuptake of specific endocannabinoids, thereby increasing their local concentration and downstream signaling. This combined modification influences the ensuing physiological responses.

Dosage and Administration Information

How to use Pacidol

The usage of Pacidol (Acetaminophen/Paracetamol) follows standardized administration rules, dosing frequency, and maximum thresholds. The medicine is indicated for use via Oral ingestion, Rectal insertion (suppositories), and Intravenous (IV) infusion.


Standard Dosing and Frequency

The standard single adult dose ranges from 325 mg up to 1,000 mg (1 gram). Doses are typically administered every 4 to 6 hours as needed, and the minimum interval between doses is established. The critical administration constraint is the maximum total daily intake, which must not exceed 4,000 mg (4 grams) within any 24-hour period from all sources of the active ingredient. This overall limit necessitates careful accounting of all prescribed and over-the-counter products containing the substance.

Administration Conditions

Oral forms of Pacidol may be taken with or without food. For accurate administration, liquid suspensions must be measured using a precise dosing device. Furthermore, specialized forms, such as extended-release tablets, are subject to a procedural restriction: they must be swallowed whole and not split or crushed.

Population Adjustments

Dose modifications are required for certain populations. For instance, the administration interval is prolonged to at least 8 hours for patients with severe renal impairment, and the maximum daily dose is reduced for individuals with hepatic impairment.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Pacidol

Evidence for Use in Managing Mild to Moderate Pain

Research examining Pacidol has included short-term Randomized Controlled Trials (RCTs), Systematic Reviews, and Meta-Analyses. These studies focused on populations experiencing outcomes related to physical discomfort, such as those associated with headaches, muscle aches, or dental procedures. The research explored Pacidol in research exploring short-term symptom changes related to mild to moderate pain.

Findings describe patterns observed in the studies related to patient-reported outcomes describing perceived discomfort. The evidence contributes to understanding symptom patterns in individuals experiencing conditions characterized by fluctuating or episodic manifestations. However, there is limited information for long-term outcomes regarding the study of pain, as follow-up durations were limited in most acute trials. The results apply only to the populations studied under those specific short-term research scenarios.

Evidence for Use in Reducing Fever (Antipyresis)

Pacidol was studied for its role in research examining temporary physiological imbalance (fever). Research primarily included controlled trials involving children and adults in conditions involving periods of heightened symptoms. Studies monitored outcomes such as the Change in Body Temperature itself and the Duration of the Afebrile State (the period without fever).

Data show patterns related to changes in temperature measurements. Research highlights changes measured during the study period, primarily documenting the outcomes related to systemic or functional imbalance over a short period. Evidence quality varies across studies due to differences in the specific dosing protocols and follow-up intervals used in past research.

Evidence in Specific Populations

Research has also monitored Pacidol in specific groups, including extensive trials in children for fever. A distinct body of research involves observational studies focused on maternal use during pregnancy and the Neurodevelopmental Outcomes in the offspring over time. The findings were mixed; some observational studies was observed in some studies to report an association, while other studies that adjusted for familial factors described different patterns. Because of the nature of the research, certainty remains low for this specific area.

What is Still Uncertain about Pacidol Research

Research is ongoing, and there are several areas where evidence is limited or where data are still emerging. The evidence highlights that research does not determine whether an individual will respond similarly and long-term effects are not fully established. The most significant gap relates to the limited information for long-term outcomes and the challenge of interpreting findings due to potential confounding by indication.

Frequently Asked Questions (FAQ)

Common questions about Pacidol (FAQ)


Q: Do most people experience a change in sleep when taking Pacidol?

A: Official product information describes the medicine as a non-sedative. Sleep changes are not typically listed as common adverse effects for the single active ingredient. When the medicine relieves symptoms like pain or fever, this change in physical state may be associated with improved rest.


Q: How long does it typically take to notice the effect of Pacidol?

A: Pharmacokinetic data from regulatory documents indicates that the concentration of the active ingredient in the blood usually reaches its peak within 30 minutes to 2 hours after ingestion. The time to reach the full effects in a population is generally noted to occur between 1 and 3 hours following administration.


Q: Does Pacidol interact with popular supplements like Vitamin D or magnesium?

A: According to major regulatory and drug interaction databases, the active ingredient in Pacidol is not associated with any known clinically significant pharmacokinetic interactions when taken with popular supplements such as Vitamin D or Magnesium.


Q: Can Pacidol affect my ability to drive or operate machinery?

A: Official product information for the single-ingredient medicine states that it generally has no influence on a person's ability to drive or operate machinery. If adverse effects such as dizziness or lightheadedness are experienced, this may affect the ability to drive or operate machinery.


Q: What if I take Pacidol and then feel nauseous an hour later?

A: Gastrointestinal discomfort, including feelings of nausea or vomiting, is listed as a potential common adverse effect in the official safety profile. This kind of reaction is a recognized possibility documented in regulatory sources.


Q: Is it possible to take Pacidol with antacids?

A: Regulatory information from interaction studies suggests that taking the medicine with common antacids, such as those containing calcium carbonate, is generally not associated with known interactions. This finding is based on standard antacid compounds and does not apply to all digestive aids, such as Cholestyramine, which is listed separately in regulatory warnings.


Q: Does Pacidol have any known interactions with alcohol?

A: Regulatory safety warnings specify an increased risk of severe liver injury for patients who engage in chronic, heavy alcohol consumption, which is defined as three or more alcoholic drinks daily. This risk is related to the liver's metabolic process as described in the official label.


Q: Why is Pacidol given for condition Y if it's primarily for condition Z?

A: The medicine is officially classified as both an analgesic (pain reliever) and an antipyretic (fever reducer). This pharmacological classification means it is approved for symptomatic relief across a range of conditions characterized by either pain or fever.


Q: Why do some people say Pacidol didn't work for them?

A: Research evidence acknowledges the concept of individual variability, meaning not every person in a population responds to the medicine in the same way. Additionally, clinical trials note that results can sometimes be influenced by confounding factors, which may lead to varied outcomes among users.


Q: Is it necessary to take Pacidol at the exact same time every day?

A: Official dosing instructions define the required minimum time interval between doses, such as every 4 to 6 hours. The focus is on ensuring the maximum daily limit is not exceeded and that doses are not taken too close together, rather than requiring a fixed, rigid time every single day.


Q: What happens when Pacidol starts to wear off?

A: The duration of action in pharmacological literature is typically described as lasting 3 to 4 hours. Once the concentration of the active ingredient in the body falls below the therapeutic level, the symptoms the medicine is approved to relieve (such as pain or fever) may return.


Q: Do you have to stop taking Pacidol slowly?

A: Official regulatory documents and prescribing information for the single-ingredient medicine do not include specific instructions for gradually stopping the use or tapering the dose.


Q: Can Pacidol interfere with routine lab blood tests?

A: The medication is known to be the subject of specific blood tests (acetaminophen level tests) used by medical professionals to monitor for potential toxicity. However, its effect on other routine lab blood tests is not widely or routinely cited in regulatory warnings.


Q: Is it normal to feel no immediate changes after starting Pacidol?

A: Pharmacokinetic research indicates that the full effect may take up to 1 to 3 hours to develop. Feeling no immediate change within the first few minutes after taking the medicine is consistent with the known onset profile.


Q: What is the estimated half-life of Pacidol according to pharmacology studies?

A: Pharmacological studies describe the elimination half-life (the time it takes for the amount of medicine in the body to decrease by half) as typically ranging from 1 to 4 hours in adults following standard therapeutic doses.


Q: Can I consume caffeine while taking Pacidol?

A: Major regulatory databases state that no clinically significant interactions have been found between the single-active ingredient in Pacidol and the consumption of caffeine.


Q: Are there different forms of Pacidol available (e.g., tablet, liquid)?

A: Official regulatory information lists multiple approved forms of the medicine. These forms include oral tablets, capsules, liquid suspensions, powders, and specialized preparations for rectal insertion or intravenous administration.

How should Pacidol be stored and disposed of?

How to Store and Dispose of Pacidol?

Pacidol (Acetaminophen/Paracetamol) must be stored and handled according to specific conditions mandated by regulatory labeling to maintain its stability and efficacy.


Storage Conditions

Requirement Official Regulatory Instruction
Temperature Store below 30 C (conditions may vary by formulation; some specify below 25 C or 35 C).
Protection Keep in the original packaging and protect from moisture and light. Do not freeze.
Safety Keep the medicine strictly out of the sight and reach of children.

Disposal Instructions

Official regulations require that unused or expired Pacidol must not be thrown away via wastewater or household waste. Instead, the mandatory instruction is to ask a pharmacist how to dispose of the medicine according to local requirements, often through a designated take-back program.

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

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