Optalgin

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Optalgin

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Treatment option: Fever

Medically reviewed

Rosario Oropesa

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 Optalgin

Property Description
Active ingredient Sodium Metamizole (Dipyrone)
Form Tablets, Solution for injection, Oral drops, Suppositories
Pharmacological class Pyrazolone derivative; Non-opioid analgesic, Antipyretic, Spasmolytic
General purpose Relief of pain and fever; easing muscle spasms
Origin Synthetic compound

What is the Core Identity and Composition of Optalgin?

Optalgin is a pharmaceutical product defined by its potent active ingredient, Sodium Metamizole, which is also frequently referenced under the name Dipyrone. This core compound is classified as a synthetic compound and is offered as a single-ingredient product. The composition utilizes the active substance combined with appropriate pharmaceutical excipients, such as a solid excipient base for tablets or an aqueous solution base for liquid preparations like oral drops and solution for injection.

To Which Pharmacological Class Does Sodium Metamizole Belong?

Sodium Metamizole is primarily classified as a pyrazolone derivative, functioning as a strong non-opioid analgesic and an effective antipyretic. It is utilized for acute discomfort across multiple clinical settings. The medicine is recognized for its efficacy in easing sudden, intense pain. The compound's mechanism provides a means of modulating pain signals. Furthermore, the availability in multiple dosage forms and diverse routes of administration is a characteristic of Metamizole.

What is Optalgin's General Purpose and Unique Action?

The general purpose of the medicine is to provide strong analgesia (pain relief) and effective antipyresis (fever reduction). It is clinically recognized for its quick onset of action in situations requiring rapid symptom control. A key differentiating feature specific to Metamizole is its inherent spasmolytic action, meaning it acts to relax the smooth muscles of internal organs. This unique triple capability—to relieve general pain, lower fever, and ease spasms—makes it useful in scenarios such as discomfort associated with renal or biliary colic, broadening the medicine’s utility compared to traditional single-action pain relievers.

What side effects are possible with Optalgin?

Possible Side Effects and Safety Information

This medicine's safety profile, as documented by regulatory bodies, focuses on potential serious but rare adverse reactions and specific population restrictions.

Serious and Clinically Significant Adverse Reactions

The most serious, though rare, risk associated with this medicine is Agranulocytosis (a severe, life-threatening reduction in white blood cells). This reaction is explicitly stated in regulatory product information as not dose-dependent, meaning it can occur at any dose or time. Related blood disorders, such as Neutropenia, have also been documented.

Other serious adverse events include life-threatening Anaphylactic Shock (severe allergic reaction), other forms of hypersensitivity, and rare cases of severe skin reactions such as Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis. Rare instances of acute liver injury, including acute hepatitis and liver failure, have also been reported.

Adverse Reactions by Frequency

Classification Examples of Reactions
Rare Agranulocytosis, Anaphylactic shock, rash
Very Rare Severe skin reactions (Stevens-Johnson syndrome, Toxic Epidermal Necrolysis)
Not Known Acute liver failure, Drug-induced liver injury, certain blood disorders

Safety Restrictions and Contraindications

Regulatory documents advise against the use of this medicine in specific circumstances and populations:

  • Pregnancy and Breastfeeding: It is contraindicated during the third trimester of pregnancy due to potential risks to the fetus and is restricted in use during breastfeeding.
  • Pre-existing Conditions: The medicine is contraindicated for patients with a history of metamizole-induced agranulocytosis, specific bone marrow disorders, or impaired blood cell formation (haematopoiesis).
  • Co-medication: Concurrent use with certain other medicines, such as Methotrexate, may increase the risk of toxicity, which requires caution as outlined in official labeling.

Overdose and Emergency Response

Overdose and when to seek help

The information below summarizes the officially documented descriptions of overdose for Sodium Metamizole (Dipyrone) and the required emergency actions as stated in government regulatory documents.

Feature Regulatory Documentation Summary
Documented overdose presentations Central Nervous System (CNS) effects including restlessness, agitation, vertigo, somnolence, convulsions, and coma. Gastrointestinal manifestations like nausea, vomiting, diarrhea, and abdominal pain (colic).
Physiological systems affected CNS, Gastrointestinal, Cardiovascular (e.g., hypotension), and Renal (e.g., acute kidney failure).
When immediate medical help is required Seek urgent medical assistance or contact emergency services immediately upon suspected overdose or the manifestation of severe, acute symptoms.

Official overdose statements:

  • Severe Outcomes: Overdose is associated with life-threatening outcomes, including severe hypotension which may progress to shock, and the potential for acute kidney failure.
  • Management: Management is defined as symptomatic and supportive. No specific antidote is known for Metamizole intoxication.
  • Procedural Steps: Regulatory summaries describe supportive measures such as gastric lavage, activated charcoal to limit absorption, and procedures like hemodialysis to accelerate metabolite elimination in severe cases.

The regulatory documents define the overdose profile by listing specific acute systemic effects and potential organ damage, such as CNS depression and renal impairment, that constitute a serious toxic event. This documentation establishes the unconditional help-seeking condition by mandating that patients seek immediate medical assistance due to the potential for life-threatening complications and the lack of a known specific antidote.

Therapeutic Uses of Optalgin

The therapeutic utility of Optalgin (Sodium Metamizole) is applied in addressing a range of distressing symptoms, including pain, fever, and spasm, which supports patients during difficult episodes by easing distress. The medicine is commonly used to help manage significant discomfort and fever that is pronounced or persistent in various clinical settings.

It is typically applied across domains where additional symptomatic support is needed, addressing symptom clusters that may become intense or disruptive in conditions such as acute trauma, post-surgical recovery, chronic neoplastic pain, and episodes of severe, cramping renal or biliary colic. This range of applications supports various patient needs:

“It is commonly used to help manage symptoms that interfere with daily comfort.”

The medication is applicable within clinical settings that involve acute or disruptive symptom patterns, and its benefit supports patients during episodes of heightened discomfort.


Quick Fact: Relief for Acute Spasmodic Pain

Optalgin is considered relevant for easing symptoms linked to organ-specific functional stress, and is used for managing acute visceral pain where smooth muscle spasm is a core component of the distress.

Regulatory References

  1. European Medicines Agency Assessment Report

Eligibility and Restrictions for Use

Regulatory documents explicitly define the patient populations for whom the use of Optalgin (Metamizole) is strictly contraindicated and for whom its use requires special consideration.

Contraindicated Populations

Optalgin must not be used in individuals with:

  • A known allergy or hypersensitivity to Metamizole, any pyrazolone or pyrazolidine derivatives (e.g., phenazone), or any component of the medicine.
  • A history of agranulocytosis (a severe blood disorder) following previous use of Metamizole or related drugs.
  • Impaired bone marrow function or established diseases of the hematopoietic system.
  • Specific metabolic disorders: acute intermittent hepatic porphyria (risk of triggering an attack) or congenital glucose-6-phosphate dehydrogenase (G6PD) deficiency (risk of hemolysis).

Age, Pregnancy, and Specific Conditions

  • Age: The medicine is contraindicated in newborns and infants under three months of age or weighing less than 5 kg.
  • Pregnancy and Lactation: Use is contraindicated during pregnancy (especially the third trimester) and during breastfeeding.
  • Caution is Required for patients with pre-existing conditions such as bronchial asthma, chronic urticaria, impaired kidney or liver function, or those with existing circulatory instability (e.g., very low blood pressure).

What should I know about interactions with other medicines?

Optalgin, which contains the active ingredient metamizole, can interact with various other medications, potentially changing their effects or increasing the risk of adverse events. It is essential to inform your healthcare provider about all prescription and over-the-counter medicines, supplements, and herbal products you are taking.

Clinically Relevant Drug Interactions

Concomitant Drug Potential Interaction Recommendation/Effect
Acetylsalicylic Acid (Aspirin) Reduced antiplatelet effect. Metamizole may interfere with aspirin's ability to inhibit blood clotting, potentially reducing the protective effect of low-dose aspirin for cardiovascular diseases.
Cyclosporin Decreased concentration. Metamizole can reduce blood levels of Cyclosporin, a drug used to prevent organ rejection, thereby decreasing its effectiveness. Blood concentration monitoring may be required.
Methotrexate Increased toxicity risk. The combination may increase the risk of blood-related toxicity, especially in the bone marrow.
Bupropion, Valproic Acid, Methadone Decreased concentration. Metamizole can lower the blood concentrations of these drugs, which may reduce their therapeutic effect, requiring close monitoring or dosage adjustment.

Other Potential Interactions

Metamizole has a complex effect on certain liver enzymes (CYP enzymes) that process many other medications. This can potentially lead to either decreased or increased levels of co-administered drugs in the blood. Other substances that may interact include the antipsychotic chlorpromazine (risk of severe hypothermia) and some antihypertensive or diuretic agents (e.g., Captopril, Triamterene), lithium, and oral anticoagulants. Caution is also advised with medications known to cause or increase the risk of agranulocytosis (a serious blood condition).

Mechanism of Action

Central Prostaglandin Synthesis Modulation

The active metabolites of Optalgin, containing metamizole, primarily inhibit the cyclooxygenase-3 ( COX-3) enzyme, a variant preferentially expressed within the central nervous system (CNS). This enzyme engagement modulates the biosynthesis of prostaglandin E2 ( PGE2) in the brain and spinal cord, resulting in altered neuronal signaling that affects afferent nociceptive processing and modifies the hypothalamic thermoregulatory set point.

Endogenous System Engagement

The drug's metabolites also influence descending pathways by engaging mechanisms that activate components of the endogenous opioidergic and cannabinoid systems in the CNS. This interaction contributes to the modulation of signaling within pain-associated pathways, influencing the regulation of specific mediators.

Smooth Muscle Relaxation

A distinct mechanistic domain involves its direct spasmolytic activity, which is mediated by inhibited release of intracellular calcium ions ( Ca^2+). This intracellular consequence, possibly linked to altered inositol phosphate synthesis, leads to the regulation of smooth muscle contraction and hypertonicity, primarily observed in visceral tissues.

Dosage and Administration Information

How to Use Optalgin (Metamizole) — Administration Guidelines

The usage of Optalgin, which contains the active substance Metamizole sodium, is governed by specific instructions concerning its route, dose quantity, and timing. These instructions ensure the medicine is administered according to established guidelines.


Administration Scope

Instruction Detail
Route of Administration Approved routes include Oral (tablets, drops), Intravenous (IV), Intramuscular (IM), and Rectal (suppositories).
Standard Dosing Adults (15 years): A single oral dose is typically 500 mg to 1,000 mg; the maximum single IV/IM dose may reach 2,500 mg. The maximum total daily intake is limited to 4,000 mg (oral) or 5,000 mg (parenteral).
Frequency and Interval Doses can be administered up to 4 times daily, but a minimum interval of 6 to 8 hours must be observed between doses. The medicine is primarily intended for short-term use.

Procedural Requirements and Adjustments

Specialized instructions govern preparation and patient-specific use. The oral form must be taken with sufficient liquid. The intravenous injection must be administered slowly over a period of at least 5 minutes.

Specific adjustments are mandated for certain populations. Pediatric dosing is based on body weight (typically 8–16 mg per kg BW for a single dose). For older adults or patients with confirmed impaired kidney or liver function, a dose reduction may be necessary due to a potential decrease in the rate of drug elimination, especially during prolonged use. If a dose is missed, patients should proceed with the next scheduled dose, maintaining the prescribed interval, and should not take a double dose.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Optalgin

Optalgin (Sodium Metamizole) has been evaluated in various clinical research settings, including controlled trials, to understand its role in research exploring certain acute and chronic symptom patterns. The available evidence describes patterns observed in specific study populations under defined conditions.


Evidence for Use in Acute and Post-Surgical Pain

This section summarizes the available evidence from randomized controlled trials (RCTs) and systematic reviews, describing the study designs and the type of pain intensity measures researchers used to assess symptom change following procedures or injury. Research primarily involved short-term RCTs in adults with post-surgical or traumatic pain. Studies monitored outcomes related to physical discomfort, comparing them to placebo or other treatments. Some trials documented patterns related to the requirement for rescue medication in the initial hours of observation. The observation periods were typically very brief, lasting only 4 to 24 hours.


Evidence for Use in Painful Colic and Spasm

This part of the overview will focus on the research exploring Optalgin for visceral pain, such as that associated with renal or biliary colic. It details the specific clinical trials and observational studies that evaluated the spasm-related component of the pain. Research explored comparisons of symptom patterns against certain comparator medications in the acute emergency setting. Findings describe patterns observed in the data, though the evidence base includes older studies, and high-quality comparative trials are limited.


Evidence for Use in High or Persistent Fever (Antipyresis)

This section reviews the comparative trials and meta-analyses that examined the rate and degree of temperature change in various patient groups. Optalgin was studied for its antipyretic properties, particularly in situations of high or persistent fever. Studies examined the aims of comparison with other fever-reducing agents in research focused on temporary physiological imbalance. The research provides context regarding its potential use when other options may not have provided sufficient resolution.


Long-Term Studies and Follow-Up Data

Research examined the use of Optalgin in chronic pain syndromes, including cancer-related pain. Studies explored patient-reported outcomes over intermediate to long-term periods. A key aspect researched was its use alongside opioid medications. Studies examined whether it was observed in some studies to be associated with changes in the required dose of opioids.


Evidence in Specific Patient Populations

Research describes specific trials conducted in children to assess its role in managing fever and pain relief. The primary acute and chronic pain trials largely included adults. Subgroup findings are uncertain or limited for the very old (older adults) or individuals with specific underlying health conditions (comorbidities) outside of those enrolled in trials.


Research Gaps and Uncertainty About Optalgin

Follow-up durations were limited across many of the initial RCTs for acute conditions, restricting the ability of studies to explore long-term effects. There is limited information from dedicated, large-scale RCTs for Optalgin used as a single agent for chronic non-cancer pain. Data for certain groups, particularly older adults and various comorbidity-defined patient groups, remain insufficient. Evidence highlights what is known — and what is still uncertain — regarding research into Optalgin in various clinical research scenarios.

Frequently Asked Questions (FAQ)

Common questions about Optalgin (FAQ)


Q: How quickly does Optalgin usually start to work?

According to official product information, a clear effect from the oral form of Optalgin can typically be expected within 30 to 60 minutes after administration. This indicates its relatively quick onset of action for pain relief.


Q: How long does the pain relief from Optalgin typically last?

Regulatory documents indicate that the dosing consideration for Optalgin is to take the medicine up to four times daily. A minimum interval of 6 to 8 hours must be observed between administrations, which suggests the typical duration of its analgesic effect.


Q: Is it true that Optalgin is banned in some countries?

Yes, regulatory reviews and official information indicate that Metamizole, the active substance in Optalgin, is restricted or banned in several countries. This includes the United States, the United Kingdom, and Canada. The availability and use of the drug vary significantly worldwide.


Q: Does Optalgin make you feel sleepy or drowsy?

Official information lists somnolence (drowsiness) and dizziness among the common adverse events associated with this medicine. Regulatory documents state that caution is necessary if somnolence or dizziness occurs.


Q: Can older adults generally use Optalgin safely?

Official documents note that a dose reduction may be applied for older adults due to the potential for delayed elimination of the active substance. This consideration relates to existing health factors like potential impaired organ function.


Q: What kind of body aches is Optalgin officially approved to treat?

The medicine is officially indicated for the treatment of acute severe pain that occurs after injuries or surgeries, pain associated with colic or tumors, and other acute, severe pain symptoms. It is also indicated for high fever when other treatments have not been successful.


Q: Do you need a prescription to get Optalgin?

The regulatory status of Optalgin (Metamizole) is not uniform globally. While it is subject to a prescription in many countries, it is available over-the-counter (OTC) in others. The requirement depends on local regulatory laws.


Q: If I take Optalgin, is it okay to drink alcohol later in the day?

Regulatory documents generally state that alcohol consumption should be avoided while taking this medicine, as the combination may be associated with an increased risk of experiencing adverse gastrointestinal effects.


Q: Does Optalgin affect birth control pills or other hormonal contraception?

Official information indicates that Metamizole can reduce the effectiveness of hormonal contraceptives, including birth control pills. This interaction may require consideration regarding the need for additional, non-hormonal contraception.


Q: Why does Optalgin have a black box warning in the US (if applicable to the core substance)?

Metamizole, the active substance in Optalgin, is not approved for marketing or use by the Food and Drug Administration (FDA) in the United States. Since the drug is not approved in the US, the concept of an FDA Boxed Warning does not apply to it there.


Q: Is Optalgin safe to take if I have high blood pressure?

Official information indicates that Metamizole has the potential to cause a severe drop in blood pressure. The medicine may also decrease the effectiveness of certain high blood pressure medications.


Q: Does Optalgin interact with blood thinners like warfarin?

The medicine can potentiate, or increase the effect of, oral anticoagulants like warfarin. This interaction may be associated with an increased potential for a bleeding event.


Q: Can Optalgin cause stomach upset or nausea?

Gastrointestinal issues are among the adverse events officially listed for Optalgin. Specifically, common issues include nausea, vomiting, and stomach or abdominal pain.


Q: How long can a person safely take Optalgin continuously?

Regulatory indications limit its use to acute, severe pain and fever. The established safety profile reflects the context of this short-term use.


Q: Are there known side effects on the kidneys from Optalgin?

Yes, renal (kidney) dysfunction is listed in official documents as a rare but potentially serious adverse effect. Other specific issues like interstitial nephritis have also been reported.


Q: Is it necessary to take Optalgin with food?

Official guidance states that oral forms of the medicine can be taken with food or immediately after a meal. Taking Optalgin with food or milk may help to prevent or reduce stomach upset.


Q: Can people with certain autoimmune diseases use Optalgin?

Due to contraindications in specific blood disorders and reports of 'autoimmune hepatitis-like' liver injury, use in individuals with complex underlying health conditions requires careful consideration.


Q: Does Optalgin interact with antidepressant medications (SSRIs)?

Yes, the official product information includes warnings about interactions with certain antidepressants. Optalgin can reduce the plasma concentration (amount in the blood) of some medications, such as sertraline, which may reduce the medicine's effectiveness.


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

Signs of a severe allergic reaction (anaphylaxis) can include difficulty breathing, swelling of the face and throat, the rapid onset of a widespread rash or hives, and a significant drop in blood pressure. If these severe symptoms are observed, emergency medical services should be contacted.


Q: Is it safe to drive after taking Optalgin?

Regulatory information indicates that caution should be exercised when driving or operating heavy machinery, as side effects such as somnolence and dizziness may occur.


Q: Can people who are lactose intolerant take Optalgin tablets?

A contraindication is listed for known hypersensitivity to the active substance or any of the non-active ingredients (excipients) in the preparation. For individuals with lactose intolerance, it is important to review the specific excipients listed for the Optalgin formulation being considered.


Q: What are the common side effects listed in the official documents?

Official documents list several adverse events that patients may experience. These include nausea, vomiting, headache, feelings of weakness, fever, abdominal pain, somnolence, vertigo, and a skin rash.


Q: What is the difference between Optalgin and its generic version?

The main differences between the brand-name product (Optalgin) and its generic version (Metamizole) are typically related to availability and cost. Differences may also be found in the excipients, or inactive ingredients, which is relevant for individuals with known allergies or sensitivities.


Q: Are there special warnings for people with heart conditions?

Yes, caution is advised for people with existing circulatory instability. Side effects such as chest pain and arrhythmias (irregular heartbeat) have been reported in the official safety information.


Q: What is the typical time frame for side effects to appear after starting Optalgin?

The time frame for side effects can vary widely. For example, severe blood disorders like agranulocytosis can occur at any time, as this risk is not dependent on the dose or duration of use. Reports of drug-induced liver injury may occur days to months after treatment initiation.

How should Optalgin be stored and disposed of?

How to Store and Dispose of Optalgin

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

Storage Requirements

Optalgin must generally be stored below 30°C and should be protected from light and moisture by keeping it in the original package. Liquid forms should have the container kept tightly closed. Solutions for injection should not be frozen. It is a mandatory requirement to store this medicine out of the sight and reach of children.

Disposal Instructions

Unused or expired Optalgin must not be thrown into household waste or flushed down wastewater. Disposal must follow the pharmaceutical waste protocols defined by local regulations. Patients should return expired medicine to a pharmacy or designated collection point for proper handling and disposal.

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

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