Mefa

Quick links to important sections

Medically reviewed

Laura Arias

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 Mefa

Quick Facts

Property Description
Active ingredient Mefenamic Acid
Form Capsule, Tablet, Oral suspension
Pharmacological class Nonsteroidal Anti-inflammatory Drug (NSAID)
Common use Pain, inflammation, and fever management
Origin Synthetic compound

What is Mefa? Active Ingredient and Composition

Mefa refers to a medicine containing the active ingredient Mefenamic Acid (INN), a synthetic compound derived from anthranilic acid. This core substance defines its pharmacological function. Mefa is supplied as a prescription drug (Rx) and is formulated as a single-ingredient product, confirming its defined structure within pharmaceutical chemistry. The chemical structure and primary role of Mefenamic Acid are established.

Pharmacological Classification and Available Forms

Mefa is formally classified as a Nonsteroidal Anti-inflammatory Drug (NSAID), belonging to the specialized Fenamate chemical subclass. This classification means the medicine is recognized for its ability to modulate the body's inflammatory response. The medicine is formulated for oral intake, with common dosage forms including the solid capsule and tablet. A differentiating feature is the availability of an oral suspension, which aids administration to the target audience of adolescents and others who may have difficulty swallowing solids.

General Purpose: Analgesia, Inflammation, and Fever Reduction

The general purpose of Mefa is to provide effective pain relief (analgesia), reduce inflammation (anti-inflammatory), and manage elevated body temperature through fever reduction (antipyretic). These three core effects are linked to its function as a cyclooxygenase inhibitor, a property that limits the synthesis of prostaglandins—the chemical messengers responsible for driving pain and inflammation. This action makes it suitable for typical use scenarios requiring the management of acute discomfort and swelling, confirming its role in symptom management.

Regulatory References

  1. NSAID
  2. cyclooxygenase inhibitor
  3. prostaglandins

What side effects are possible with Mefa?

Possible Side Effects and Safety Information

The safety profile of Mefa (Mefenamic Acid) is categorized by governmental regulatory bodies based on the likelihood and nature of adverse reactions observed during clinical use and surveillance. These classifications define the officially documented risks associated with the medicine.


Adverse Reaction Classification

Side effects are primarily grouped by the affected System-Organ-Class:

  • Gastrointestinal Disorders: These are among the most frequently documented adverse effects, including diarrhea, nausea, vomiting, and abdominal pain.
  • Nervous System Disorders: Common reactions include headache, dizziness, and drowsiness.
  • Serious Adverse Reactions officially noted include Gastrointestinal bleeding, ulceration, and perforation, as well as the risk of serious Cardiovascular Thrombotic Events such as Myocardial Infarction and Stroke. Rare but severe Skin Reactions (e.g., Stevens-Johnson Syndrome) are also documented.

Population and Exposure Safety Notes

Official regulatory documents detail specific safety considerations for certain patient groups and duration of use:

Safety Context Officially Documented Safety Consideration
Older Adults Have an increased risk of serious Gastrointestinal bleeding and perforation.
Pregnancy Contraindicated in late pregnancy (after 30 weeks) due to risk to the fetus.
Long-Term Use Risk of serious Cardiovascular and Gastrointestinal Events may increase with longer durations of therapy.
Restrictions Contraindicated for peri-operative pain after Coronary Artery Bypass Graft (CABG) surgery and in cases of severe renal or hepatic failure.

The safety profile is structured to clearly define risks, separating the Common effects, such as diarrhea and headache, from the Serious events that require specific attention, ensuring the description adheres strictly to official regulatory standards.

Overdose and Emergency Response

The regulatory information for Mefenamic Acid (Mefa) overdose focuses on specific clinical manifestations and mandated emergency responses.

Overdose may manifest with Central Nervous System (CNS) effects such as extreme tiredness, drowsiness, confusion, and the documented risk of convulsions (seizures). Gastrointestinal signs include nausea, vomiting, epigastric pain, and gastrointestinal bleeding, which may present as bloody vomit or black, tarry stools. Serious outcomes documented in regulatory files include coma and the potential for acute renal failure.

Focus Regulatory Statement
Antidote No specific antidotes are known or available.
Management Management is through symptomatic and supportive care. Activated charcoal may be indicated if administered within four hours of ingestion, particularly following a large overdose.

Immediate medical attention is required upon any suspected overdose. Regulatory guidance explicitly states that emergency services must be contacted immediately if the individual exhibits severe signs. These include the occurrence of a seizure, collapse, difficulty breathing, or the inability to be awakened. These manifestations are considered life-threatening and require urgent, specialized observation.

Therapeutic Uses of Mefa

What Mefa Treats: Main Uses and Benefits

Mefa (Mefenamic Acid) may assist with managing symptoms related to physical discomfort and systemic imbalance across several key therapeutic areas. The medication is utilized for easing mild to moderate acute pain, and plays a role in managing primary dysmenorrhea (painful cramping) in women's health. It is commonly used when short-term symptomatic assistance is needed, such as in clinical scenarios like post-procedural discomfort or addressing episodic manifestations like heavy menstrual bleeding (menorrhagia).

The medication may also be part of symptomatic management for conditions presenting with inflammatory or irritative processes, including joint stiffness and discomfort associated with arthritis, and plays a role in managing elevated body temperature (fever). This provides support that helps ease the overall symptom burden and assists patients with coping more steadily with symptom fluctuations.

“Mefa is relevant for easing symptoms related to heightened physiological activity and helps contribute to improved day-to-day comfort.”


Quick Fact: Relief for Pain, Cramps, and Fever

Use Category Common Conditions/Symptoms Addressed Patient Benefit
Pain & Inflammation Mild to moderate acute pain, arthritic discomfort, post-procedural soreness. Supports patients during episodes of heightened discomfort.
Women's Health Painful menstrual cramping, heavy menstrual bleeding (menorrhagia). Helps maintain a sense of stability when symptoms are more noticeable.
Systemic Symptoms Elevated body temperature (fever). Supports general well-being during symptomatic phases.

Regulatory References

  1. NIH DailyMed overview of Mefenamic Acid

Eligibility and Restrictions for Use

This information outlines the official eligibility and non-eligibility rules for this medicine, strictly based on authoritative government regulatory documents.

Populations for Whom Use is Prohibited or Limited

Mefa is officially contraindicated (must not be used) in patients who meet any of the following criteria:

  • Hypersensitivity: Those with a known allergy to this medicine or any of its components, or who have experienced asthma, hives (urticaria), or allergic reactions after taking aspirin or other Nonsteroidal Anti-inflammatory Drugs (NSAIDs).
  • Gastrointestinal Disease: Individuals with active ulceration or chronic inflammation of the upper or lower gastrointestinal tract.
  • Cardiovascular Surgery: Patients undergoing or recovering from coronary artery bypass graft (CABG) surgery.
  • Renal Function: Patients with pre-existing renal disease or significantly impaired renal function.

Use in Specific Populations

Population Category Official Eligibility Status
Age Approved for patients 14 years of age and older. Use in children under 14 is generally not established.
Pregnancy Avoid use from 20 weeks of gestation onward due to potential risk to the fetus, particularly after 30 weeks.
Lactation Use is not recommended in nursing mothers, as trace amounts of the medicine may be present in breast milk.

Official documents also stipulate that use requires caution and often close monitoring for patients with conditions such as uncontrolled hypertension, pre-existing congestive heart failure, or impaired hepatic (liver) function. Use is typically restricted to a duration that usually does not exceed one week (7 days).

What should I know about interactions with other medicines?

Interactions with other medicines and products

Official regulatory documentation identifies several clinically significant interaction patterns for Mefenamic Acid (Mefa), categorized by their effect on drug exposure and pharmacodynamic risk.

Pharmacodynamic and Risk-Based Interactions

Co-administration with Oral Anticoagulants (e.g., Warfarin) is documented to enhance their effects, increasing the risk of gastrointestinal and non-gastrointestinal bleeding by displacing the anticoagulant from protein binding sites. Similarly, taking Mefa with Corticosteroids, SSRIs (Selective Serotonin Reuptake Inhibitors), or Anti-platelet Agents increases the documented risk of gastrointestinal ulceration or bleeding. Mefa may also reduce the antihypertensive efficacy of ACE Inhibitors and Angiotensin II Antagonists, with a noted increased risk of renal function deterioration in elderly patients and those with impaired renal function. The use of Mefa is contraindicated in the treatment of peri-operative pain during Coronary Artery Bypass Graft (CABG) surgery and with other systemic non-aspirin NSAIDs.

Pharmacokinetic and Substance Interactions

Interactions that alter plasma drug levels are formally documented. Mefa causes a reduction in the renal clearance of Lithium and Methotrexate, which elevates their plasma concentrations and increases the risk of toxicity. Mefa is also documented to inhibit the metabolism of certain Oral Hypoglycaemic Agents (sulfonylureas), leading to a prolonged half-life and increased risk of hypoglycemia. A specific timing-based restriction states Mefa should not be taken for 8 to 12 days following Mifepristone administration. Furthermore, Magnesium-containing Antacids are officially noted to significantly increase the rate and extent of Mefa absorption, while Alcohol consumption increases the risk of gastrointestinal bleeding.

Mechanism of Action

How Mefa Works

Mefa (Mefenamic Acid) operates across distinct biological domains, leading to defined physiological alterations that result from its activity.


1. Dual Modulation of Eicosanoid Biosynthesis

Mefa primarily functions as a non-selective, reversible inhibitor of the Cyclooxygenase (COX-1 and COX-2) enzymes. By restricting the enzymatic conversion of arachidonic acid into prostaglandins (e.g., PGE2), the drug limits the production of these mediators, which are responsible for sensitizing peripheral pain nerves and regulating the brain's thermoregulatory center. This mechanism results in a reduction of localized tissue signaling and the lowering of the hypothalamic temperature set-point.


2. Direct Interaction with Central Signaling

Beyond enzyme inhibition, Mefa acts as a positive allosteric modulator of specific GABAA receptors within the Central Nervous System (CNS), thereby enhancing the brain's natural inhibitory tone. This secondary mechanism contributes a central component to the drug's activity by increasing the inhibitory tone within key neural circuits.


3. Receptor-Level Antagonism and Physiological Constraints

The drug exhibits direct blockade on certain Prostanoid (EP) Receptors, which interrupts the binding of prostanoid mediators to their cellular targets. However, its non-selective COX inhibition also affects the COX-1 dependent production of homeostatic prostanoids necessary for gastric mucosal defense and renal perfusion regulation.

Dosage and Administration Information

How Mefa Is Used: Official Administration Guidelines

Administration of Mefa (Mefenamic Acid) is restricted to the oral route (by mouth), utilizing available forms such as capsules, tablets, or oral suspension. Usage follows a strictly defined, short-term protocol.

Standard Dosing and Frequency

For approved short-term uses, such as acute pain or primary dysmenorrhea, the administration protocol starts with an initial loading dose. The standard adult regimen begins with a single dose of 500 mg, followed by maintenance doses of 250 mg taken at fixed intervals, typically every 6 hours. This structured regimen is designed to be used on an as-needed basis for symptom management.

Contextual Use and Duration Constraints

The medicine is subject to strict constraints regarding duration. Use for acute pain must not exceed 7 days. For primary dysmenorrhea, treatment generally lasts 2 to 3 days, beginning at the onset of symptoms or menstrual flow. All administration must adhere to the principle of using the lowest effective dose for the shortest necessary duration.

To minimize potential gastrointestinal effects, Mefa is administered with food, milk, or antacids.

Population-Specific Rules

Specific guidelines apply to certain patient groups. The drug is not recommended for children under 14 years for approved indications. Older adults (65 years) are instructed to use the lowest effective dose for the shortest duration possible.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Mefa (Mefenamic Acid)


Evidence for Use in Acute Pain and Fever

Research was studied for outcomes related to physical discomfort and elevated body temperature. Studies mainly rely on short-term Randomized Controlled Trials (RCTs), and systematic reviews, that have explored Mefa's use in the acute management of mild to moderate pain and elevated body temperature (fever). These studies typically evaluated Mefa in adult populations to track outcomes related to systemic or functional imbalance. Findings describe patterns observed in the studies related to the timing and extent of measured pain relief compared to a placebo or other active agents. However, the evidence is primarily derived from settings with varying symptom burdens related to acute or episodic changes.


Evidence for Use in Women's Health Indications

Mefa was studied for conditions characterized by fluctuating or episodic manifestations, such as those that present in women's health. For primary dysmenorrhea (painful menstrual cramping), research mainly consists of RCTs applied in studies examining patient-reported experiences. These trials tracked outcomes related to physical discomfort during periods of heightened symptom activity. Research has examined the use of Mefa for heavy menstrual bleeding (menorrhagia), where studies monitored outcomes related to daily functioning or activity level alongside objective measurements of blood loss. However, follow-up durations were limited for both indications, usually covering only a few cycles.


Scientific Uncertainty and Research Gaps

The evidence base contributes to the broader evidence landscape but also reveals limitations. The primary limitation is that there is limited information for long-term outcomes or durability of response, as research heavily favors short-term and single-episode trials. Long-term outcomes are not well characterized, and data are still emerging regarding the sustained effects of Mefa when used repeatedly. Additionally, evidence describing patterns for Mefa's use in older adults is less extensive compared to that for acute adult populations. Research provides context but not individual predictions.

Frequently Asked Questions (FAQ)

Common questions about Mefa (FAQ)


Q: How should Mefa be stored to maintain its effectiveness?

A: Regulatory documents state that Mefa tablets should be stored at room temperature, which is generally below 30°C. They should be kept in the original packaging to protect them from both moisture and light. Following proper storage instructions helps ensure the medicine remains stable until its expiration date.


Q: What is the main purpose of Mefa, and what conditions is it used for?

A: Mefa is a medication indicated for the management of type 2 diabetes mellitus. Official product information specifies that it is used to help improve blood sugar control in adults. It can be utilized alone or in conjunction with other medicines prescribed for diabetes treatment.


Q: Is Mefa safe to use during pregnancy or while breastfeeding?

A: According to the official product information, Mefa is not typically recommended for use during pregnancy. The medication is also generally advised against while breastfeeding, as it is unknown if Mefa passes into breast milk. Regulatory labeling advises consulting a healthcare professional to discuss all treatment options if you are pregnant, planning pregnancy, or breastfeeding.


Q: What are the common side effects that a person might experience when taking Mefa?

A: Studies and official information indicate that very common gastrointestinal side effects associated with Mefa include nausea, vomiting, diarrhea, and stomach pain. Loss of appetite and taste disturbance are also common. Official product information notes that these effects are often seen when treatment begins and and may lessen as the body adjusts.


Q: What happens if a dose of Mefa is missed?

A: Official information advises that if a dose of Mefa is forgotten, it should be skipped completely. The labeling specifies taking the next dose according to the regular schedule. Regulatory guidance warns against attempting to compensate for a missed dose by taking an extra amount of medicine.


Q: Does Mefa cause weight gain or weight loss?

A: Regulatory documents and clinical studies suggest that Mefa is typically associated with maintaining a stable body weight or experiencing modest weight loss. Official information indicates that Mefa treatment is not generally associated with weight gain, which can occur with some other therapies for diabetes.

How should Mefa be stored and disposed of?

The official regulatory requirements for storing Mefenamic Acid (Mefa) mandate maintaining specific environmental controls to preserve product stability.

Official Storage Requirements

Mefa must be stored at controlled room temperature, specifically between 20 C to 25 C (68 F to 77 F), with permitted excursions up to 30 C. The container must be kept tightly closed and stored in the original container to ensure protection from moisture and excess heat, and must be kept from freezing. All medication must be stored out of the sight and reach of children.

Disposal Instructions

Unused or expired Mefa must be disposed of in accordance with local and national regulations. To protect the environment, the product should not be flushed down the toilet or allowed to enter sewage systems or surface water; instead, consumers should utilize available drug take-back programs.

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

Available in countries:

Equivalent of Mefa found in:

A-Z Index: