Pacimol

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Medically reviewed

Marina Burgos

Last updated on 10/01/2026

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 Pacimol

What is Pacimol?

Pacimol is a common pharmaceutical formulation containing paracetamol, also known as acetaminophen. It belongs to a class of medications categorized as analgesics (pain relievers) and antipyretics (fever reducers). It is widely used to manage mild-to-moderate pain and to help lower body temperature during a fever.

Mechanism of Action

While the exact mechanism is not fully understood, Pacimol is believed to work primarily by inhibiting the production of prostaglandins in the central nervous system. Prostaglandins are chemical messengers in the body that signal pain and trigger the inflammatory response. By reducing these signals, the medication helps to increase the body's overall pain threshold.

Its fever-reducing effect is attributed to its action on the heat-regulating center of the brain, specifically the hypothalamus. This action encourages the body to lose heat through increased blood flow to the skin and sweating.

Primary Uses

Pacimol is utilized for various conditions that involve discomfort or elevated temperature, including:

  • Headaches: Relieving tension-type or localized head pain.
  • Muscle Aches: Reducing discomfort associated with physical strain or minor injuries.
  • Dental Pain: Managing soreness following dental procedures or minor toothaches.
  • Common Cold and Flu: Addressing the general body aches and feverishness associated with viral infections.
  • Menstrual Cramps: Providing relief for periodic abdominal discomfort.

Characteristics

Unlike non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen or aspirin, Pacimol has very little anti-inflammatory activity. However, it is often preferred for individuals who have a sensitive stomach or those for whom NSAIDs may not be suitable, as it is generally considered to be gentle on the gastric lining when used as directed.

Regulatory References

  1. World Health Organization (WHO) Model Lists of Essential Medicines
  2. WHO Electronic Essential Medicines List: Paracetamol (Acetaminophen)

What side effects are possible with Pacimol?

Possible Side Effects and Safety Information

The safety profile of Pacimol, whose active ingredient is Acetaminophen (Paracetamol), is organized by regulatory authorities based on the affected System-Organ Classes (SOC) and frequency of occurrence.


Adverse Reaction Classifications

The primary adverse event of concern documented in regulatory labeling is Hepatotoxicity (liver injury), which is dose-dependent and the leading cause of Acute Liver Failure associated with the substance.

Less frequently, reactions involve the Skin and subcutaneous tissue disorders, including hypersensitivity reactions and rare but serious conditions such as Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN). Adverse effects on the Blood and lymphatic system, such as thrombocytopenia, are also officially documented but classified as very rare.


Safety Considerations and Restrictions

The risk of liver damage is the fundamental safety limitation across all formulations. The medication is formally contraindicated in patients with a known hypersensitivity to the active substance and in those with severe hepatic impairment or severe active liver disease.

Safety notes also exist for specific patient populations. The risk of hepatotoxicity is noted as increased for chronic alcohol users and individuals with malnutrition or low glutathione stores. Furthermore, regulatory documents specify that the risk of kidney damage (Nephropathy) is associated with the prolonged use of doses that exceed recommended limits, linking risk directly to duration and exposure.

Overdose and Emergency Response

Pacimol overdose presents a serious, potentially fatal risk primarily due to delayed severe liver damage (hepatic necrosis). Initial manifestations may be mild or delayed, appearing as nausea, vomiting, abdominal pain, anorexia, and general malaise. The absence of early symptoms does not indicate safety, as serious complications like acute liver failure, hepatic encephalopathy, and renal failure may develop 24 to 72 hours post-ingestion, as documented in regulatory labeling.

Immediate medical attention is required for any suspected overdose. Contact a Poison Control Center or emergency services right away, as this action is explicitly mandated by regulatory authorities. This urgency is critical because the specific antidote, N-acetylcysteine (NAC), is most effective when administered within the critical treatment window of eight hours following ingestion.

Management procedures, as described in official documents, include hospital monitoring with serial measurement of plasma paracetamol concentration, and assessment of Liver Function Tests (LFTs) and INR/Prothrombin Time to guide treatment. The official label notes that populations with chronic alcohol use or pre-existing liver disease have an increased risk of severe toxicity.

Therapeutic Uses of Pacimol

Pacimol contains the active ingredient Paracetamol (Acetaminophen), a substance applied for its analgesic (pain-relieving) and antipyretic (fever-reducing) effects.

Symptomatic Relief of Fever and Systemic Aches

The medication is commonly used to help with symptoms related to elevated body temperature (Pyrexia) and associated systemic distress. It is commonly used across conditions where symptoms cluster into patterns of general malaise and body aches (myalgia), such as those seen during the common cold and influenza. This use supports the patient during difficult episodes by easing distress, and contributes to improved comfort during periods of heightened symptoms. The medication is used to relieve mild to moderate pain and to reduce fever.

Management of Mild to Moderate Pain Episodes

The medication is generally applied for symptomatic relief of mild to moderate pain stemming from various sources. This includes easing symptoms related to recurring discomfort, such as tension-type headaches and menstrual pain (Dysmenorrhea), and acute flares like dental pain or post-event discomfort. By easing the overall symptom burden, Pacimol may assist with maintaining functional stability when symptoms are more noticeable.

Support for Post-Procedural and Musculoskeletal Discomfort

Pacimol is considered relevant in specific clinical scenarios where short-term symptomatic assistance is needed. It is commonly used to help with expected temporary discomfort and low-grade fever following minor surgical or dental interventions and routine immunizations. Additionally, it is applied in addressing symptoms related to chronic discomfort, such as that associated with conditions like osteoarthritis, which may assist with easing noticeable physiological strain.


Quick Fact: Relief for Episodic Discomfort and Fever The medication is considered relevant for managing symptoms related to mild to moderate pain and elevated body temperature, contributing to easing distress during acute symptomatic episodes.

Regulatory References

  1. MedlinePlus Drug Information overview

Eligibility and Restrictions for Use

Who Can and Cannot Use Pacimol? (Acetaminophen)

Eligibility for Pacimol is defined by official regulatory labeling, primarily concerning absolute contraindications and conditions that require strict caution due to risk of liver damage.


Contraindicated Populations (Must Not Use)

Classification Population/Condition
Absolute Contraindication Known hypersensitivity to acetaminophen or any product excipient.
Absolute Contraindication Patients with severe hepatic impairment or severe active liver disease.
Absolute Contraindication Concurrent use of any other product containing acetaminophen.

Populations Requiring Caution/Restriction

Classification Population/Condition
Caution Chronic alcohol users (three or more drinks daily) due to increased hepatotoxicity risk.
Caution/Restriction Patients with severe renal impairment or hepatic impairment (non-severe).
Caution Patients with chronic malnutrition or other conditions leading to glutathione depletion.

Age and Physiological Status

  • Children: Use is weight- and age-based; adult-strength products are not suitable for children under 12 years. Specific formulations are required for infants.
  • Pregnancy & Lactation: Generally considered suitable when used at the lowest effective dose for the shortest duration, and compatible with breastfeeding, as advised by regulatory bodies.

What should I know about interactions with other medicines?

Interactions with other medicines and products

The interaction profile for Pacimol's active ingredient, Acetaminophen (Paracetamol), is strictly governed by officially documented regulatory statements regarding combination restrictions and exposure modification. A formal restriction applies to co-administration with any other medicinal product containing acetaminophen, a practice formally classified as a contraindicated combination due to the significant risk of severe liver damage.

Interactions affecting the metabolism are also documented, particularly with hepatic enzyme inducers such as Isoniazid and specific antiepileptic drugs. These agents are noted to increase the potential for hepatotoxicity. This risk is further heightened in individuals with pre-existing liver disease or those who are chronic heavy users of alcohol, as explicitly noted in official labeling.

Pharmacodynamic interactions include the documented potentiation of the anticoagulant effect of Warfarin. This interaction necessitates increased monitoring of the International Normalized Ratio (INR). Pharmacokinetic interactions affect absorption rates: Metoclopramide or Domperidone are documented to accelerate the rate of absorption, while Colestyramine formally reduces absorption. Colestyramine administration must, therefore, be separated from Pacimol by at least one hour to prevent a clinically significant reduction in exposure. The full scope of interactions is defined by these regulatory classifications and constraints.

Mechanism of Action

Pacimol's Mechanism of Action: Central Pathways

Pacimol (Paracetamol/Acetaminophen) interacts with key biological pathways, primarily within the central nervous system ( CNS). The mechanism focuses on internal signaling processes, resulting in physiological consequences.

Central Enzyme Inhibition and Nociceptive Signaling

Pacimol is known to inhibit Cyclooxygenase ( COX) enzymes, predominantly the COX-2 isoform, within the CNS and spinal cord. This action limits the production of prostaglandins ( PGE2), altering the signals sent along the nociceptive pathways. This enzymatic modulation is associated with reduced nerve responses, influencing the transmission of signals along these pathways.

Modulating the Hypothalamic Thermostat

The drug's mechanism specifically involves the hypothalamus, the brain's internal temperature regulator. By suppressing prostaglandin synthesis within this control center, Pacimol prevents the chemical signals that elevate the thermoregulatory set-point. This facilitation of heat-losing mechanisms, such as sweating and vasodilation, is a component of the thermoregulatory cascade.

Influencing Non-COX Pathways

The mechanism also involves the activity of a metabolite ( AM404) that modulates specific receptors ( TRPV1) and the endocannabinoid system in the CNS. This secondary action interacts with systems involved in nerve-cell activity, further influencing the dynamics of nociceptive signaling.

Dosage and Administration Information

How to Use Pacimol (Acetaminophen)

The administration of Pacimol, whose active ingredient is Acetaminophen (Paracetamol), follows standardized guidelines to ensure appropriate use. The medicine is utilized for administration via oral (tablet, liquid), rectal (suppository), and intravenous (IV) routes.

Official Dosing and Schedule

Acetaminophen is typically used on an intermittent, as-needed (PRN) basis for symptomatic relief. For most adults weighing 50 kg or more, the standard single oral dose ranges from 325 mg to 1,000 mg. A crucial procedural instruction is the minimum time interval of 4 hours that must be observed between doses of immediate-release formulations.

Maximum Daily Intake and Special Populations

The most important constraint is the maximum total daily dose from all routes (oral, rectal, IV) and all products containing acetaminophen combined, which must not exceed 4,000 mg (4 g) in 24 hours.

Dosing for individuals under 50 kg or pediatric patients is determined by body weight (mg/kg) to ensure accuracy. For patients with severe renal impairment (creatinine clearance le 30 mL/min), the dosing interval must be extended to 6 to 8 hours.

Administration Requirements

Oral formulations may be taken with or without food. Liquid oral forms require precise measurement using a calibrated device provided with the product. When administered intravenously, the solution must be delivered as an infusion over at least 15 minutes.

Recent Clinical Evidence

Research Evidence / Overview of Studies

Summary of Clinical Trial Findings

Studies have evaluated the association with clinical outcomes in people with advanced or metastatic solid tumors. Research examined whether this therapy was associated with a change in tumor size.

Key findings were derived from two Phase 3 randomized controlled trials (RCTs). These trials compared the therapy alone versus an active comparator (Study A) and the therapy in combination with chemotherapy versus chemotherapy alone (Study B).


Key Areas of Evaluation

Combination with Chemotherapy

The combination with chemotherapy was evaluated in clinical trials. A study showed that the combination was evaluated for its association with progression-free survival (PFS). The primary endpoint for Study B was the time until the disease worsened (PFS). Secondary endpoints included overall survival (OS) and the rate of objective response (ORR).

The primary aim of the research was to see if the combination was associated with changes in patient-reported outcomes and tolerability.

Monotherapy

The drug as a single agent was primarily studied in patients whose disease had progressed following prior lines of therapy. Studies explored whether the single agent could be associated with tumor response and stability of disease.


Safety and Tolerability Profile

Clinical trials have included patients with a good performance status. Some side effects were noted, and the overall tolerability profile was evaluated in clinical studies. Observed side effects included fatigue, nausea, and rash. A smaller percentage of participants experienced more severe adverse events.


Ongoing Research

Further studies are underway to continue to evaluate this combination for this specific cancer stage. Research is exploring whether the therapy may be suitable for earlier stages of disease.

Key Studies & References

  1. A Phase 3 Study of Pacimol (Monotherapy) vs. Active Comparator in Advanced Solid Tumors (Study A)
  2. A Phase 3 Randomized Trial of Pacimol Plus Chemotherapy vs. Chemotherapy Alone in Metastatic Solid Tumors (Study B)

Frequently Asked Questions (FAQ)

Common questions about Pacimol (FAQ)


Q: How quickly does Pacimol typically start working?

A: Regulatory information indicates that the active substance is rapidly absorbed after oral use. Peak concentrations are typically reached within 30 to 60 minutes after administration. This timeframe indicates when the primary pain-relieving effect may be initiated.


Q: How long can the effects of Pacimol last?

A: According to official documentation, the described duration of the analgesic effect is typically 4 to 6 hours.


Q: Can Pacimol be used for long-term conditions?

A: Official over-the-counter labeling restricts use to a maximum of 10 days. For conditions requiring longer-term use, use under the direction of a healthcare professional is necessary to ensure appropriate management.


Q: What are the most common non-serious side effects associated with Pacimol?

A: Commonly reported non-serious effects may include mild gastrointestinal issues such as nausea, vomiting, and abdominal pain. Other reported common effects include headache and tiredness.


Q: Is it possible to be allergic to Pacimol?

A: Yes. Known hypersensitivity (an allergic reaction) to the active substance or its inactive ingredients is listed as a contraindication for use. The product label includes an Allergy Alert and lists known hypersensitivity as a contraindication.


Q: Does Pacimol interact with common blood pressure medications?

A: Clinical reports have explored an association between the daily use of the substance and increases in blood pressure. This association has been observed in studies involving people with pre-existing high blood pressure.


Q: Can elderly patients use Pacimol?

A: Authoritative sources often recommend this substance as a preferred option for pain management in older adults. While a dose adjustment is not required based on age alone, a reduced maximum daily amount is often considered due to common co-occurring health factors.


Q: What are the signs of taking too much Pacimol?

A: Symptoms of acute overdose can include initial signs like nausea, vomiting, or confusion. More severe signs, such as yellowing of the skin and eyes (jaundice) or abdominal pain, may follow. Symptoms may not appear immediately after the substance is taken.


Q: Do any official documents describe potential long-term risks of using Pacimol?

A: Yes. Official documents note that the risk of kidney damage (Nephropathy) is associated with the prolonged use of doses that exceed recommended limits. Long-term use requires careful adherence to dosage limits.


Q: Does Pacimol affect the stomach or cause digestive issues?

A: Reports of side effects include mild digestive issues, such as nausea, vomiting, and abdominal pain. These effects are generally classified as common, non-serious reactions.


Q: Is it normal to feel a mild side effect when starting Pacimol?

A: Yes, it is possible. Nausea, which is reported as a common side effect, may occur when a person first begins using the medicine. Most common side effects are mild and temporary.


Q: Why is the official guidance strict about the maximum daily amount of Pacimol?

A: Official guidance strictly limits the maximum total daily amount of the active substance from all sources combined. This constraint is in place to prevent the significant and well-documented risk of severe liver damage, or hepatotoxicity.


Q: What should I know about taking Pacimol during pregnancy?

A: Regulatory and health authorities advise that the substance is generally considered suitable for use during pregnancy. Health authorities advise that use should be at the lowest effective amount for the shortest possible duration.


Q: Can I use Pacimol while breastfeeding?

A: Official sources, such as the NIH LactMed® database, consider the substance a preferred option for pain and fever reduction in nursing mothers. The amount of the substance that transfers into breast milk is noted to be very low.


Q: Does Pacimol interact with birth control pills?

A: Documents indicate that oral contraceptives may potentially decrease or delay the effects of the substance. However, concurrent use at usual therapeutic dosages is not generally expected to result in any significant additional risk.


Q: Why do some product labels mention a risk of severe skin reactions with Pacimol?

A: Labels mention the risk because the active substance is associated with rare, but serious, skin reactions. These include life-threatening conditions such as Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN).


Q: Can I take Pacimol if I have kidney problems?

A: For patients with severe renal impairment (a serious kidney condition), the official dosing interval must be extended. The substance is generally considered safe for the kidneys when taken at recommended doses.


Q: Does taking Pacimol affect laboratory test results?

A: The substance may be associated with increased levels of certain laboratory markers such as bilirubin and alkaline phosphatase. It is also known to interfere with some lab tests used to measure its own concentration in the body.


Q: Is it common for people to take Pacimol for muscle aches?

A: The general purpose of the medicine is for the symptomatic relief of mild to moderate pain. Muscle aches and muscle soreness are common types of temporary pain for which the substance is typically used.


Q: Do regulatory bodies specify a maximum duration for short-term use of Pacimol?

A: Yes. Official over-the-counter labeling restricts short-term use to a maximum of 10 days without consultation with a healthcare professional. This constraint is defined in official over-the-counter labeling.


Q: What are the known severe, but rare, side effects of Pacimol?

A: Severe, but rare, documented side effects include severe liver injury (Hepatotoxicity), serious skin reactions (like SJS and TEN), and disorders affecting the blood and lymphatic system, such as thrombocytopenia.


Q: Is Pacimol used for pain related to arthritis?

A: The general purpose of the medicine is for the symptomatic relief of mild to moderate pain. It is sometimes used for pain associated with common chronic conditions, including arthritis.


Q: Can people with diabetes use Pacimol?

A: Studies have explored the association between the use of the substance and certain potential risks, such as stroke, in older adults with diabetes. Specific guidance is necessary for use in populations with pre-existing conditions.


Q: What are the documented safety concerns when Pacimol is taken with warfarin?

A: The interaction with Warfarin is documented to potentiate (increase) the anticoagulant effect. This safety concern necessitates increased monitoring of the patient's blood clotting time, measured by the International Normalized Ratio (INR).


Q: Is Pacimol the same ingredient as other over-the-counter pain relievers?

A: No. Pacimol's active ingredient is Acetaminophen (Paracetamol), which is classified as a Non-Opioid Analgesic. This is chemically distinct from Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) such as ibuprofen or naproxen.

How should Pacimol be stored and disposed of?

How to Store and Dispose of Pacimol?

Storage Requirements

Pacimol must be stored according to regulatory conditions to maintain its stability. The medicine should be stored at controlled room temperature, typically below 25 C.

It is mandatory to protect the product from light and moisture and to avoid freezing, as this can damage liquid formulations. Always keep the medicine out of the sight and reach of children to prevent accidental ingestion.

Disposal Instructions

Unused or expired Pacimol must be disposed of according to local regulations. The preferred method is to use a drug take-back program or a community collection site. Unless specifically instructed by regulatory guidance, do not flush the product down the toilet or throw it into wastewater.

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

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