Meftan

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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 Meftan

What is Meftan? A Concise Overview

Property Description
Active Ingredient Mefenamic Acid
Form Oral Capsule or Tablet
Pharmacological Class Nonsteroidal Anti-Inflammatory Drug (NSAID)
General Purpose Relief of pain and inflammation
Origin Synthetic Compound

What Type of Medicine is Meftan? (Definition and Classification)

Meftan is the common name associated with medications containing the active ingredient mefenamic acid, which is classified as a Nonsteroidal Anti-Inflammatory Drug (NSAID). This places it in the fenamate group of pain relievers, chemically differentiating it from common NSAIDs like ibuprofen.

Mefenamic acid is clinically recognized for its effectiveness against a particular type of discomfort known as primary dysmenorrhea (menstrual pain). This indicates its specific utility in addressing pain that often involves cramping and is short-term in nature. The active ingredient is a synthetic compound, ensuring a standardized, consistent, and predictable therapeutic agent in every dose.


Composition, Form, and General Purpose

The key component in this medication is mefenamic acid, the sole active pharmaceutical ingredient (API). It is typically found in a solid oral form, such as capsules or tablets, designed for systemic absorption and widespread relief throughout the body.

The general therapeutic purpose of Meftan is to provide symptomatic relief by reducing both pain and inflammation. Its core mechanism involves inhibiting the synthesis of prostaglandins, which are chemical mediators responsible for triggering the body’s inflammatory response. Mefenamic acid is used for acute pain relief across various patient needs, serving as an option for easing intense, temporary discomfort.

Regulatory References

  1. NIH/MedlinePlus

What side effects are possible with Meftan?

Possible Side Effects and Safety Information for Meftan (Mefenamic Acid)

Meftan, a nonsteroidal anti-inflammatory drug (NSAID), carries important safety warnings regarding serious adverse reactions affecting multiple body systems. To minimize potential risks, this medication should be used at the lowest effective dose for the shortest necessary duration.

Serious Cardiovascular and Gastrointestinal Risks

Official regulatory information emphasizes that the use of this class of drugs can increase the risk of serious, potentially fatal, cardiovascular thrombotic events, including heart attack and stroke. This risk may increase with the duration of use. Similarly, NSAIDs can cause an increased risk of serious gastrointestinal (GI) adverse events, such as bleeding, ulceration, and perforation of the stomach or intestines, which can occur at any time without warning symptoms.

Other Serious and Common Adverse Reactions

Serious skin reactions, including life-threatening conditions like Stevens-Johnson Syndrome (SJS), Toxic Epidermal Necrolysis (TEN), and Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) syndrome, have been reported. Other serious risks involve renal toxicity (kidney damage or failure), heart failure, and hypertension (high blood pressure). Common adverse effects generally include symptoms involving the gastrointestinal tract, such as diarrhea, abdominal pain, nausea, and dyspepsia, as well as central nervous system effects like headache and dizziness.

Key Safety Restrictions and Contraindications

Meftan is contraindicated for the treatment of pain right before or after coronary artery bypass graft (CABG) surgery. It must not be used in patients with active GI ulceration, significant renal impairment, or a history of asthma, hives, or other allergic-type reactions after taking aspirin or other NSAIDs. Patients with known cardiovascular disease or risk factors should be monitored closely for signs of serious events. Symptoms suggesting severe reactions, such as chest pain, sudden numbness, bloody stools, or persistent rash, require immediate medical attention.

Overdose and Emergency Response

Meftan overdosage is officially characterized by distinct manifestations affecting multiple physiological systems. Documented presentations include gastrointestinal disturbances such as nausea, vomiting, epigastric pain, and diarrhea. Central Nervous System (CNS) effects are also noted, including disorientation, drowsiness, excitation, and tinnitus. A primary concern documented in regulatory statements is the potential for severe CNS toxicity, specifically convulsions (seizures), which are associated with a high, dose-related risk. Other serious outcomes include gastrointestinal bleeding and, rarely, acute renal failure.

Management of an overdosage must consist of symptomatic and supportive care, as official regulatory prescribing information states that no specific antidote is known for Mefenamic Acid. Immediate medical attention must be sought for any suspected overdose. Urgent medical help is required if the affected individual experiences severe signs, such as a seizure, collapse, or difficulty breathing, exactly as instructed by government health authorities. Procedural instructions for management include the potential use of activated charcoal and an osmotic cathartic in a clinical setting, provided the agent is administered within four hours of ingesting a large dose. Forced diuresis or hemodialysis are generally documented as being not useful due to the drug’s properties.

Therapeutic Uses of Meftan

What Meftan Treats: Main Uses and Benefits

Meftan (Mefenamic Acid) may be used in clinical contexts where supportive symptom management is appropriate to address pain, inflammation, and fever. It is relevant across therapeutic domains characterized by episodic or acute symptom patterns that can cause temporary functional strain or discomfort.

Meftan is commonly used across conditions presenting with acute episodes, including primary dysmenorrhea (menstrual pain), mild to moderate acute pain (such as dental or post-surgical discomfort), and symptoms related to inflammatory or irritative states, like those associated with osteoarthritis. This application helps address symptom clusters that may become intense or disruptive.

“The primary goal of using Meftan is to contribute to improved comfort during periods of heightened symptoms.”

Easing Pain and Systemic Discomfort

Meftan may be applied when symptoms are pronounced, and can assist with easing the symptom load of intense, throbbing pain, particularly during menstruation. It offers symptomatic relief in settings where short-term symptomatic assistance is needed, and may help manage symptoms when pain becomes momentarily overwhelming. Furthermore, it may be applied to ease challenging systemic symptoms by providing a fever-reducing benefit, which contributes to easing the overall symptom load when body temperature is elevated.

Quick Fact: Supportive Relief for Acute Pain
Primary Focus: May be part of symptomatic management of acute, short-term pain episodes, commonly including menstrual cramps and dental discomfort.

Regulatory References

  1. NIH DailyMed Official Indications

Eligibility and Restrictions for Use

Official Eligibility and Contraindications

Meftan (Mefenamic Acid) is an NSAID whose use is defined by strict regulatory exclusions, primarily relating to a patient's history and underlying organ health.

Populations Contraindicated (Must Not Use) Populations for Whom Use is Not Recommended/Restricted
History of asthma, hives, or other allergic-type reactions after taking aspirin or any other NSAID. Patients under 14 years of age (safety and efficacy not established).
Active ulceration or chronic inflammation of the upper or lower gastrointestinal tract. Women who are nursing/breastfeeding (drug passes into breast milk).
Pre-existing or significantly impaired renal function or advanced kidney disease. Elderly patients (use with caution due to increased GI and renal risks).
Treatment of peri-operative pain in the setting of Coronary Artery Bypass Graft (CABG) surgery. Patients with severe heart failure (unless closely monitored).
Late pregnancy (starting at about 30 weeks gestation) due to risk of fetal harm.

Eligibility is conferred only upon individuals aged 14 and older who do not possess any of the documented contraindications. The drug's regulatory profile heavily emphasizes exclusions to mitigate risks associated with cardiovascular events, serious hypersensitivity, and compromise to the GI or renal systems.

What should I know about interactions with other medicines?

Interaction Map: Interactions with other medicines and products — official regulatory information for Meftan

Interaction Scope

Category Official Regulatory Information for Mefenamic Acid
Medicinal product categories with documented interactions Nonsteroidal Anti-inflammatory Drugs (NSAIDs), Oral Anticoagulants, SSRIs, Diuretics, Antihypertensives (ACE Inhibitors, AIIA), Antacids, Cytotoxic Agents.
Specific interacting medicines (if explicitly listed) Acetylsalicylic acid (low-dose), Lithium, Methotrexate, Mifepristone, Magnesium Hydroxide.
Mechanistic basis of interactions (only if stated in label) Inhibition of metabolism of oral hypoglycemic agents; displaced from protein binding sites (e.g., Warfarin); reduction in renal clearance (e.g., Lithium, Methotrexate); CYP2C9 metabolism.
Timing-based interaction rules (if applicable) Mifepristone: Must not be taken for 8–12 days following administration of Mifepristone.
Population-specific interaction notes (if applicable) Increased risk of acute renal failure when co-administered with diuretics and/or ACE Inhibitors/AIIA, particularly in the elderly or those with impaired renal function.

Interaction Classifications (High-Level)

Classification Type Official Regulatory Classification/Basis
Interaction severity classification Formal Contraindication (CABG surgery pain); Clinically significant risk of enhanced effect (Anticoagulants), reduced efficacy (Diuretics), and increased exposure (Lithium, Methotrexate).
Regulatory basis FDA and EMA-aligned official labeling.

Official Interaction Statements:

  • Co-administration with Oral Anticoagulants is documented to enhance their effects, increasing the risk of gastrointestinal and non-gastrointestinal bleeding.
  • Co-use with Diuretics or Antihypertensives reduces their therapeutic efficacy and increases the official risk of acute renal failure.
  • Lithium and Methotrexate exposure is officially documented to increase due to reduced renal clearance/elimination.
  • Antacids containing Magnesium Hydroxide are formally documented to significantly increase the rate and extent of Mefenamic Acid absorption.
  • Alcoholic beverages, Corticosteroids, and SSRIs are documented to increase the official risk of gastrointestinal bleeding when co-administered.

Connection to the overall interaction profile (2–4 sentences): Regulatory documents define this profile by focusing on additive pharmacodynamic risks (bleeding/organ toxicity) and pharmacokinetic changes that alter plasma concentrations of co-administered drugs. This framework establishes specific constraints, prohibitions (such as avoiding other systemic NSAIDs), and timing rules based on the potential for reduced efficacy or enhanced risk of serious adverse events.

Mechanism of Action

Primary Mechanism: Inhibition of Prostaglandin Synthesis Pathway

Meftan (mefenamic acid) primarily exerts its effect through the non-selective inhibition of the Cyclooxygenase (COX-1) and COX-2 enzymes. These enzymes are requisite for converting arachidonic acid into prostaglandins and other eicosanoid inflammatory mediators. By competitively restricting the active sites of these enzymes, Meftan limits the biosynthesis of prostaglandins. This inhibition results in a decrease in the concentration of local inflammatory mediators and a reduction in the excitability of peripheral nociceptors, altering pain signal transmission.


Secondary Mechanisms: Molecular Cascade Interference

Meftan also engages with other biological targets, contributing to its overall pharmacodynamic profile. It acts as an inhibitor of the NLRP3 inflammasome, a multi-protein complex involved in the processing and release of the pro-inflammatory cytokine IL-1beta. Furthermore, the compound modulates the activity of certain ion channels (e.g., TRPC6) and receptors within the central and peripheral nervous systems. These actions influence neuronal excitability and neuroinflammatory processes, contributing to the overall physiological effects of reduced sensitization and diminished inflammatory signals.

Dosage and Administration Information

Meftan, which contains mefenamic acid, is administered solely by the oral route, utilizing solid dosage forms such as capsules or tablets, or a liquid suspension. The medicine is designed for short-term use only, with administration limited to defined courses.

The standardized adult dosing regimen begins with an initial loading dose of 500 mg. This is followed by a maintenance dose of 250 mg, to be taken every six hours as needed. For acute pain, the duration of use is typically restricted to a maximum of seven days, and for primary dysmenorrhea, treatment is generally limited to two or three days per cycle. Clinical guidance indicates that the lowest effective dose should be used for the shortest duration possible, and the total daily dose should not routinely exceed 1,000 mg.

A key administration instruction is the necessity of taking Meftan with food, milk, or an antacid. For cyclic conditions, dosing should commence at the onset of bleeding and associated symptoms. Specific guidance for pediatric use exists, where the oral suspension form may be utilized for children over six months in certain jurisdictions, often based on weight, while solid forms are generally not recommended for those under 14 years.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Meftan

The information below summarizes the available research concerning Meftan (Mefenamic Acid). This summary describes what types of studies have been conducted, what has been observed so far in those studies, and what areas of research remain uncertain or require further data.


Evidence for Use in Primary Dysmenorrhea (Menstrual Pain)

Research was evaluated in studies focused on the use of Meftan for conditions characterized by fluctuating or episodic manifestations of menstrual pain. This evidence largely comes from short-term Randomized Controlled Trials (RCTs). Researchers was studied for outcomes related to physical discomfort, monitoring patient-reported outcomes describing perceived discomfort. The studies conducted during periods of increased symptom activity reported various patterns in pain scores over the short assessment periods when Meftan was used. Research also explored how measured outcomes differed when compared to control groups or other standard therapies. Despite the available trials, certainty remains low regarding the full range of experiences, and long-term effects are not fully established.

Evidence for Relief of Mild to Moderate Pain

Meftan was evaluated in research exploring short-term symptom changes related to physical discomfort, such as pain following minor surgical procedures. These studies monitored patient-reported outcomes describing perceived discomfort and the time interval before subjects requested additional pain relief. The research describes that studies report how symptoms evolved in the observed populations over intervals of a few hours to one or two days. The available evidence for general pain outcomes related to physical discomfort is limited, as studies focused heavily on acute or disruptive episodes of short duration, and sample sizes were modest in some pain models.

What Is Still Uncertain About Meftan Research

Evidence highlights what is known — and what is still uncertain. Comparative evidence is lacking against newer treatment options, and the evidence quality varies across studies. A significant gap exists in understanding the long-term context, as long-term effects are not fully established, and follow-up durations were limited in many key trials. Additionally, subgroup findings are uncertain, as the results apply only to the populations studied, and data for certain groups remain insufficient regarding diverse populations and co-existing conditions.

Frequently Asked Questions (FAQ)

Common questions about Meftan (FAQ)


Q: Is Meftan intended for short-term use only, or can it be taken long-term?

According to the official product information, Meftan is explicitly indicated for short-term use. For treating acute pain, use is typically restricted to a maximum of seven days. Using the medication for longer periods of time is not generally recommended in official guidance.


Q: Is it advised to avoid or limit alcohol consumption while using Meftan?

Regulatory documents state that co-administering Meftan with alcoholic beverages is documented to increase the official risk of gastrointestinal bleeding. This increased risk is a critical consideration noted in the product information.


Q: What is the official information regarding Meftan use during pregnancy?

Official information from regulatory agencies states that use of Meftan is generally avoided from about 30 weeks of gestation onward. This is due to potential risks to the fetal heart and the developing kidneys. The drug's profile for use between 20 and 30 weeks is characterized by limits in dose and duration.


Q: Is Meftan generally considered appropriate for use while breastfeeding?

Trace amounts of the drug may be present in breast milk. Official labeling states that because of the potential for serious reactions in nursing infants, a decision must be considered whether to discontinue breastfeeding or discontinue the drug, taking the mother's medical need into account.


Q: Why do official documents recommend taking Meftan with food or milk?

Official guidance states that Meftan should be taken with food, milk, or an antacid. This guidance is included to describe the aim of reducing the possibility of stomach irritation and minimizing gastrointestinal upset.


Q: What are the differences in risks for older adult patients taking Meftan?

Official patient information indicates that older adults may face an increased risk of specific adverse effects. These risks include serious gastrointestinal events and a higher likelihood of age-related kidney problems, which is why these patients are noted for use with caution in official documents.


Q: What is the mechanism of action for Meftan beyond simply blocking pain signals?

Beyond its primary action of blocking pain-causing chemicals, Meftan also engages with other biological processes. It is documented to inhibit a multi-protein complex called the NLRP3 inflammasome, which is involved in inflammation, and influences certain ion channels in the nervous system.


Q: How quickly can a person generally expect Meftan to start providing relief?

Pharmacokinetic data indicates that the medicine is rapidly absorbed following oral administration. The concentration of the drug typically reaches its maximum level in the bloodstream approximately two to four hours after a dose.


Q: How long does the pain relief from one dose of Meftan typically last?

The official pharmacokinetic data describes the elimination half-life of mefenamic acid as approximately two hours. This measurement indicates the time required for the amount of drug in the body to be reduced by half.


Q: What is the evidence regarding Meftan's potential effect on fertility or ovulation?

Studies conducted in animals have explored the potential effects of this class of drugs on reproduction. Official documents mention that as an inhibitor of prostaglandin synthesis, the drug has been associated with increased pre- and post-implantation loss in animal models.


Q: Can Meftan be used to reduce fever, or primarily for pain and inflammation?

Mefenamic acid is classified as a Nonsteroidal Anti-Inflammatory Drug (NSAID). The medicine exhibits activity for reducing pain and inflammation, and its documented effects extend to antipyretic (fever-reducing) action.


Q: What should a user know about the risk of fluid retention or swelling with Meftan?

Official safety warnings indicate that fluid retention and edema (swelling caused by trapped fluid) have been observed with the use of this class of medicine. The regulatory safety warnings describe that caution applies to use in patients who have conditions that may be worsened by fluid retention.


Q: What is the potential for Meftan to cause a weight change?

Official regulatory documents list unusual weight gain as a possible warning sign of a serious adverse reaction. This symptom may be related to the drug's potential for causing fluid retention.

How should Meftan be stored and disposed of?

How to Store and Dispose of Meftan (Mefenamic Acid)


Storage Requirements

Mefenamic acid must be stored according to regulatory labeling to maintain product integrity. The medication should be kept at room temperature, generally not exceeding 30 C (86 F), and must be protected away from excess heat and moisture. Store the capsules in the container they came in and keep the lid tightly closed.

Critically, always store this medication out of the sight and reach of children and use child-resistant caps where provided.

Disposal Instructions

The most recommended method for discarding unused or expired Meftan is utilizing a drug take-back program. If this is unavailable, the medicine can be mixed with an unappealing substance (like dirt or coffee grounds) and sealed in a bag for disposal in the household trash. Do not dispose of mefenamic acid by flushing it down a toilet or pouring it down a drain.

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

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