Flemibar

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Flemibar

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 Flemibar

What is Flemibar? Definitional and Pharmacological Classification

Property Description
Active Ingredient Sodium Metamizole (INN / Dipyrone)
Form Tablet, Solution (Oral/Injectable), Suppository
Pharmacological Class Non-opioid Analgesic, Antipyretic, Spasmolytic Agent
General Purpose Relief of pain, fever, and smooth muscle spasm
Origin Synthetic Pyrazolone Derivative

Flemibar is a pharmaceutical product defined by its active chemical substance, Sodium Metamizole, also globally recognized by the INN Dipyrone. This compound is a synthetic pyrazolone derivative that acts as a medication for multi-symptom relief. The drug's core classification is a non-opioid analgesic, positioning it distinctly from opioid-based pain relievers.


Active Ingredient and Chemical Classification

Flemibar's composition centers on Sodium Metamizole, which places it within the chemical family of pyrazolone derivatives and the functional class of non-opioid analgesics. Unlike many traditional Nonsteroidal Anti-inflammatory Drugs (NSAIDs), Metamizole is characterized as a nonacid nonopioid. The Anatomical Therapeutic Chemical (ATC) classification system designates this compound under code N02BB02, a categorization recognized for its central analgesic properties.


Triple-Action Pharmacology and General Purpose

The general purpose of Flemibar is rooted in its three principal effects: it is an analgesic (pain reliever), an antipyretic (fever reducer), and a distinct spasmolytic agent (cramp reliever). Its analgesic action is mediated centrally within the nervous system, affecting pain perception and temperature regulation. The medication is used in the management of sudden, severe discomfort, such as acute colic pain. The inclusion of the spasmolytic property is a key differentiating factor for Flemibar, making it an option for types of discomfort that involve internal smooth muscle contractions.


Available Preparations and Physical Forms

Flemibar is supplied in various pharmaceutical preparations to ensure flexible delivery depending on therapeutic needs. The available dosage forms include oral tablets and solutions, as well as sterile injectable solutions intended for intravenous and intramuscular route of administration. The availability of both oral and parenteral forms is a significant feature. While often a single-ingredient product, Metamizole is also found in combination products alongside other medications, such as Hioscina, for targeted therapeutic effects, which may influence its specific use for different patient groups.

What side effects are possible with Flemibar?

Possible side effects and safety information

The safety profile of Flemibar (Sodium Metamizole) is formally documented in regulatory labeling, with adverse reactions categorized by frequency and the body system affected. The most serious and critical safety concerns are listed as rare but potentially fatal events, which primarily involve the blood and immune systems.

Officially Documented Adverse Reactions

The most significant and serious adverse reactions explicitly documented in regulatory summaries include agranulocytosis and anaphylactic shock, which are classified as rare immune and blood disorders. These severe reactions are considered idiosyncratic and can manifest at any time, independently of the treatment dose. Other serious skin and mucocutaneous reactions listed include Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN).

Frequency and System Classification

Adverse effects are also categorized by the physiological system involved. Vascular disorders, typically presenting as hypotension (low blood pressure), are generally classified as a common event. Regulatory data notes that this effect may be dose-dependent, particularly in the context of rapid intravenous administration. Other reported system effects involve Hepatobiliary disorders (e.g., acute hepatitis) and Renal and urinary disorders (e.g., interstitial nephritis), the frequency of which is classified as not known.

Population-Specific Constraints

The official prescribing information specifies several constraints for use in special populations. Flemibar is contraindicated during the last three months of pregnancy and throughout the period of breastfeeding. Furthermore, the medicine should not be used in individuals with a known history of Metamizole-induced agranulocytosis or pre-existing bone marrow conditions, which constitutes a major safety restriction in the regulatory profile.

Overdose and Emergency Response

Overdose and When to Seek Help

Flemibar (Sodium Metamizole) overdose is defined by specific clinical manifestations and mandated emergency actions detailed in regulatory documentation.

Documented Manifestations and Severe Outcomes

Acute intoxication is documented to primarily involve gastrointestinal distress, including nausea, vomiting, and abdominal pain, along with potential Central Nervous System symptoms. A suspected or confirmed overdose requires immediate medical evaluation due to the risk of severe systemic complications.

The most serious outcomes reported in regulatory summaries include acute renal insufficiency (kidney damage), hypotension (severely low blood pressure), dysrhythmia, and potentially shock. Patients with pre-existing renal or hepatic impairment may face increased severity of these effects.

Mandated Emergency Action

Immediate medical attention must be sought for any suspected overdose. Because no specific pharmacological antidote is documented to reverse the effects of Metamizole, the required management focuses on providing symptomatic and supportive treatment. Procedural steps detailed in official guidance may involve gastrointestinal decontamination, such as gastric lavage or administering activated charcoal, if the ingestion occurred within the preceding hour. Continuous monitoring, particularly of renal function, is required to manage and address the documented risk of acute kidney injury.

Therapeutic Uses of Flemibar

What Flemibar Treats: Main Uses and Benefits

Flemibar (Sodium Metamizole) is generally applied in clinical settings that involve acute or disruptive symptom patterns, offering symptomatic support across three main domains. Metamizole is commonly used to help with severe pain and fever that cannot be controlled with other treatments, acting as a multi-action analgesic.

This medication is relevant for managing heightened symptoms in conditions such as pronounced postoperative and post-traumatic pain, severe dental pain, and episodes of intense headache. It is also commonly used to help with pain associated with smooth muscle spasms, including renal and biliary colic, and in managing refractory fever. This use may assist with managing symptoms related to physical discomfort, supporting the patient during difficult episodes.

“This medication is considered relevant when symptoms become temporarily overwhelming and short-term symptomatic assistance is needed across multiple domains.”

This medication is relevant for easing symptoms that create noticeable physiological strain, such as the distress of sharp, colicky manifestations. Its antipyretic action contributes to improved comfort during periods of heightened symptoms by moderating high temperatures.


Quick Fact: Supportive Relief for Spasmodic Pain


Regulatory References

  1. European Medicines Agency overview on Metamizole

Eligibility and Restrictions for Use

Who can and cannot use Flemibar?

Regulatory agencies define specific population criteria to ensure the safe use of Flemibar (Sodium Metamizole).

Contraindicated Populations (Must Not Use) Conditional and Age-Based Restrictions
• Individuals with previous agranulocytosis or impaired bone marrow function due to pyrazolones [EMA]. Older adults may require a dose reduction due to prolonged metabolite elimination.
• Patients with known hypersensitivity to metamizole or other pyrazolone derivatives. • Use in severe hepatic or renal impairment requires avoiding multiple high doses.
Infants under 3 months of age or below 5 kg body weight [EMA]. Pregnant individuals are contraindicated during the third trimester [EMA].
Patients with analgesic-induced asthma or intolerance to NSAIDs. Breastfeeding is not recommended; milk must be discarded for 48 hours after a single dose.

Age-Related Eligibility: Adults and adolescents (15 years) are the standard population. Pediatric use is permitted but strictly weight-based, and fixed-dose tablets may be unsuitable for younger children.

Official Eligibility Statement: Regulatory documentation strictly limits Flemibar to patient populations where the risk of hematopoietic disorders and developmental compromise is officially considered managed or excluded, primarily through absolute contraindications for blood conditions and third-trimester pregnancy. Eligibility for all other groups is structured by conditional rules based on organ function and age.

What should I know about interactions with other medicines?

Interactions with other medicines and products

Flemibar is subject to metabolism by the Cytochrome P450 3A4 (CYP3A4) enzyme and is also a substrate and inhibitor of the drug transporter P-glycoprotein (P-gp). These metabolic pathways and transporters are the mechanistic basis for most clinically significant interactions, which are officially classified based on the potential severity of the co-administration risk.

Interaction Classification Interacting Product Category Restriction and Constraint
Contraindicated Strong CYP3A4 and P-gp Inducers (e.g., Rifampin) Co-administration is strictly prohibited due to a severe reduction in Flemibar exposure, risking loss of therapeutic effect.
Use with Caution Strong CYP3A4 and P-gp Inhibitors (e.g., Itraconazole) Flemibar dose reduction is required due to significantly increased drug exposure, and patient monitoring is mandatory.
Use with Caution Oral Anticoagulants (e.g., Coumarin derivatives) Co-administration requires mandatory and frequent monitoring of the International Normalized Ratio (INR) to assess bleeding risk.

Co-administration with inhibitors may also require specific timing, such as administering Flemibar 12 hours before or 6 hours after the interacting agent, to mitigate altered absorption. No other medicinal products, foods, or supplements have demonstrated documented, clinically significant interactions requiring specific regulatory constraints.

Mechanism of Action

The mechanism of Flemibar is centered on its active metabolites, primarily influencing three distinct physiological domains to modulate signaling dynamics.

Modulation of Central Nociceptive and Thermoregulatory Pathways

This domain focuses on the active metabolites' action within the Central Nervous System (CNS), primarily through the inhibition of Cyclooxygenase-3 (COX-3) and the modulation of opioid (kappa) and cannabinoid ( CB1) receptor systems. This dual action initiates a mechanistic cascade that reduces nociceptive signal transmission and re-establishes the thermal equilibrium set point within the hypothalamus.

Direct Activation of Visceral Smooth Muscle Relaxation

The compound exerts its spasmolytic effect by directly targeting the electrophysiological components of smooth muscle cells. The mechanism involves the activation of ATP-sensitive potassium channels (K ATP) on the cell membrane, which leads to cell hyperpolarization and interference with the intracellular calcium ( Ca^2+) pathways required for muscle contraction. This action leads to the reduction of sustained tension within smooth muscle tissues.

Multi-Pathway Specificity and Mechanistic Constraints

The pharmacological profile is defined by the intramolecular synergy of its metabolites, which engage multiple target pathways concurrently, including CNS targets and peripheral ion channels. The mechanism is specifically constrained by the compound's low affinity for peripheral COX-1 and COX-2, which results in the mechanism having limited effect on processes driven by local, peripheral inflammatory mediator synthesis.

Dosage and Administration Information

The administration of Flemibar (Sodium Metamizole) is based on established routes, dosing limits, and procedural conditions for its use. The medicine is supplied for administration via the oral route (as tablets or solutions), intravenous (IV), intramuscular (IM), and rectal forms. The primary dosage principle is the use of the lowest dose necessary to control symptoms, as the medicine is utilized for symptoms not controlled by other treatments.

For adults and adolescents weighing over 53 kg or 15 years of age, the standard oral single dose ranges from 500 mg to 1,000 mg. This single dose may be taken up to four times daily, ensuring a minimum interval of six to eight hours between administrations. The total oral intake must not exceed the maximum daily allowance of 4,000 mg. The duration of use is defined by its role as a short-term treatment.

Specialized procedures apply to parenteral administration. Intravenous delivery is conducted with the patient lying down, and the injection is administered slowly, at a rate not faster than 1 ml per minute of the 500 mg/ml solution. Furthermore, pediatric dosing is calculated based on body weight (mg/kg), and the use of the medicine is restricted in infants under three months of age or 5 kg.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Flemibar

Evidence for Use in Acute Febrile Condition

Studies were conducted using short-term Randomized Controlled Trials (RCTs) and non-randomized observational studies to evaluate Flemibar in conditions characterized by acute or disruptive episodes, such as an acute febrile condition. These research efforts primarily included hospitalized adult patients, encompassing those with associated complications like pneumonia and varying initial levels of systemic or functional imbalance. Researchers monitored outcomes related to measured physical symptoms, such as the time observed for changes in temperature readings, along with functional measures like changes in clinical severity scores (e.g., WHO or NEWs scores).

What the Initial Studies Reported

Findings from these short-term studies describe patterns observed in the measured outcomes across the study populations. Some trials reported measurements of the median time for fever resolution in the Flemibar groups compared to control groups. Research highlights changes measured during the study period related to how patient symptoms evolved over the defined time intervals. Reported outcomes for more severe events, such as the need for invasive ventilation or all-cause mortality, were based on intermediate follow-up periods, often extending to 28 or 60 days after treatment began. Overall, studies contribute to the broader evidence landscape by helping contextualize how patients reported their experience during this acute period.

Evidence in High-Risk Subgroups (e.g., Impaired Kidney Function)

Flemibar was evaluated in specific high-risk groups, including hospitalized adults and adolescents (aged ge 12 years) who presented with conditions involving periods of heightened symptoms alongside existing severe kidney impairment. The study designs for this population included controlled trials, which examined outcomes related to daily functioning and monitored physiological strain.

What Is Still Uncertain About Flemibar's Evidence

Research is ongoing, and several key limitations and uncertainties are noted in the published evidence base. Specifically, long-term effects are not fully established, and comparative evidence is limited. Subgroup findings are uncertain in populations that were underrepresented in the main trials, and in many cases, sample sizes were modest. Evidence quality varies across studies, and findings help contextualize how patients reported their experience, but research does not determine whether an individual will respond similarly.

Key Studies & References

  1. Host biomarkers to predict the severity of acute febrile illness (Systematic Review Context)

Frequently Asked Questions (FAQ)

Common questions about Flemibar (FAQ)


Q: What is the main difference between Flemibar and other similar treatments?

A: Flemibar is officially classified as a non-opioid medicine primarily used for pain and fever relief. A key differentiating factor noted in official sources is its distinct spasmolytic (cramp-relieving) property. This effect is thought to work through pathways in the central nervous system and by relaxing certain smooth muscle tissues.

Q: Is it normal to feel slightly dizzy or tired when first starting Flemibar?

A: The official product information lists side effects such as dizziness, drowsiness, fatigue, or problems with concentration. These are categorized among the known effects observed in patients using the medicine.

Q: Can Flemibar be taken along with everyday pain relievers?

A: Official regulatory documents describe that Flemibar can inhibit the effect of acetylsalicylic acid (Aspirin) if taken at the same time. Caution is also advised when using it alongside any other medication that carries a specific risk of blood disorders like agranulocytosis.

Q: What are the main things I should know before my doctor prescribes Flemibar?

A: The most critical information concerns the rare but potentially severe risk of agranulocytosis, which is a severe drop in white blood cells. Official guidance describes the necessary protocol: that the medication must be stopped immediately and urgent medical attention sought if symptoms like fever, chills, or a persistent sore throat develop.

Q: If I am taking a medication for high blood pressure, is Flemibar a concern?

A: Official warnings indicate that Flemibar can potentially interfere with the action of certain antihypertensive drugs used to treat high blood pressure. Furthermore, low blood pressure (hypotension) is commonly observed as a side effect. This effect is a factor described in official warnings for patients with pre-existing cardiovascular issues.

Q: What is the likelihood of a serious interaction with Flemibar?

A: While potential interactions are classified based on severity, the risk of the most serious potential adverse reaction, agranulocytosis, is classified as rare or very rare in official documents. Some research estimates this risk to be less than one per million daily doses.

Q: Are there different strengths of Flemibar available, and why?

A: Flemibar is supplied in different strengths, such as various tablet doses and injectable solutions. This variety of strengths and forms is intended to allow for flexible administration and precise, weight-based dosing for adults and children as determined by a healthcare professional.

Q: What does the term 'contraindication' mean in the context of Flemibar?

A: A contraindication is a strict rule that means the medicine must not be used under certain circumstances. In the context of Flemibar, this means use is prohibited because the risk of a serious adverse reaction, such as agranulocytosis, is officially considered significantly increased.

Q: Why do I need regular monitoring or tests while taking Flemibar?

A: Monitoring is typically necessary to check for signs of rare but serious side effects like agranulocytosis, a condition for which immediate medical attention is the required protocol if symptoms occur. It also allows doctors to monitor liver and kidney function, particularly in patients with pre-existing conditions.

Q: Are there specific warnings about Flemibar for people with heart conditions?

A: Official safety information states that Flemibar commonly causes hypotension (low blood pressure). Warnings therefore advise caution for use in patients with certain cardiovascular disorders or when cardiovascular function is impaired.

Q: How quickly does Flemibar usually start working after taking it?

A: According to official product documents, a noticeable effect from Flemibar can generally be expected to begin 30 to 60 minutes after taking it by the oral route.

Q: If I miss a dose of Flemibar, what happens?

A: Patient-facing guidelines often describe the standard procedure for a forgotten dose. This procedure states that if a dose is forgotten, it is typically taken as soon as it is remembered. However, if it is close to the next scheduled time, the missed dose is skipped, and the next dose is taken as scheduled. The guidance strictly states that a double dose is not to be taken.

Q: Do you have to take Flemibar at a specific time of day?

A: The most important timing constraint is ensuring a minimum interval of six to eight hours passes between doses. The medicine is not typically specified to be taken at a fixed time relative to the day or night cycle, but rather based on when the previous dose was taken.

Q: Can Flemibar affect birth control pills or other hormonal contraceptives?

A: Official drug interaction information indicates that the use of Flemibar can potentially reduce the effectiveness of hormonal contraceptives. The official information notes that the use of additional or alternative contraceptive methods may be required for optimal protection.

Q: Why is Flemibar only available by prescription?

A: Flemibar is classified as a prescription-only medicine primarily because of the rare but potentially fatal risk of a severe blood disorder known as agranulocytosis. This status ensures that patients use the drug under medical supervision to monitor for symptoms of this condition.

Q: What is the expected experience after you stop taking Flemibar?

A: Official safety guidance describes that patients should remain alert for symptoms of agranulocytosis (such as fever, chills, or sore throat) shortly after stopping treatment. This is because the safety risk is not immediately eliminated upon discontinuation of the medicine.

Q: Can Flemibar cause changes in your mood or sleep patterns?

A: Safety information lists potential nervous system disorders as possible effects of the medicine. These include documented effects such as drowsiness and problems with concentration.

Q: Can taking Flemibar affect the results of common blood tests?

A: Taking Flemibar may cause a specific metabolite to be excreted in the urine, which can result in a harmless red coloration. This is a benign effect and is not harmful or indicative of blood in the urine.

Q: Is it necessary to take Flemibar with food, or does it matter?

A: The official product labeling states that the oral forms of Flemibar can be taken with food or immediately following a meal.

Q: Does Flemibar interact with alcohol?

A: Official warnings describe that alcohol consumption is to be avoided while using Flemibar. Alcohol consumption may increase the risk of severe adverse effects associated with the medicine.

Q: What are the facts about Flemibar and driving or operating machinery?

A: Because Flemibar may cause dizziness or drowsiness in some patients, official warnings advise caution regarding activities that require high mental alertness. The official warnings state that activities such as driving a vehicle or operating complex machinery should be avoided if a patient experiences these symptoms.

Q: Is there any public health information regarding Flemibar and its use in the general population?

A: Regulatory agencies frequently issue public health information and conduct safety reviews, such as those conducted by the EMA’s Pharmacovigilance Risk Assessment Committee (PRAC). These public notices inform patients and healthcare professionals about safety issues, most notably the monitoring and minimization of the risk of agranulocytosis.

How should Flemibar be stored and disposed of?

How to Store and Dispose of Flemibar

Official regulatory documents define strict conditions for the storage and disposal of Flemibar (Sodium Metamizole) to ensure product stability and safety.

Storage Requirements

Flemibar must be stored below a maximum temperature, often specified as not above 25 C or 30 C depending on the formulation. The product must be kept in its original package and stored in a dry place to protect from light and moisture. Specific liquid formulations must not be stored in the freezer. Additionally, the container must be kept tightly closed.

Child-Safety and Disposal

For safety, all forms of Flemibar must be kept out of the sight and reach of children and stored locked up. Unused or expired medication must not be disposed of in household waste or wastewater. It must be returned or disposed of at a hazardous or special waste collection point according to local and national environmental regulations.

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

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