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Mefenamic acid: what it is for, dosage and side effects

by Alivia Nyhan
Published: Last Updated on

People may need medication to relieve pain, and mefenamic acid is an option. This medicine belongs to the group of non-steroidal anti-inflammatory analgesics (NSAIDs); It has the property of stopping the production of an enzyme known as cyclooxygenase, which causes pain, inflammation, and fever.

Various pathologies trigger the appearance of these latter symptoms, which is why they use mefenamic acid is required after a medical evaluation.

In this FastlyHealarticle, you will learn much more about mefenamic acid: what it is for, dosage, and side effects.

What is mefenamic acid for

It is essential to know the benefits of mefenamic acid and what it serves for its correct treatment:

  • Treat pain ranging from mild to moderate, even severe.
  • It treats primary dysmenorrhea and can be taken before and during the menstrual period.
  • Decreases uterine contractions.
  • Relieves pain after insertion of intrauterine devices.
  • Cures fever due to its antipyretic effect.
  • It is used to treat diseases such as arthritis, osteoarthritis, and inflammations of non-rheumatic origin.

Mefenamic acid dosage

Mefenamic acid can be administered orally or, in some cases, rectally. The dose must be prescribed by the doctor and will depend on each patient’s diagnosis.

Mefenamic acid for adults

500mg every 8 hours will be indicated orally or even in the form of suppositories rectally for an adult.

In this sense, a decreased dose of 250 mg can be given every 6 hours in cases of intolerance to the drug. It is essential to consult your doctor about this option if you suffer from this intolerance.

To treat dysmenorrhea or menorrhagia in adults, it should be administered orally every 8 hours from the start of menstruation until completing 2 or 3 days of treatment, when the discomfort ceases.

Mefenamic acid for children

  • Children from 2 to 8 years will be indicated: 1 suppository of 125 mg every 8 hours.
  • Children from 8 to 14 years will be administered 1 suppository of 250 mg.
  • Over 14 years: 2 capsules of 250 mg or 1 suppository of 500 mg 3 times a day will be indicated.

It is recommended that the use of mefenamic acid is not longer than one week.

Side effects of mefenamic acid

Taking mefenamic acid can cause some side effects, such as:

  • Headache.
  • Dizziness.
  • Nervousness.
  • Ringing in the ears.
  • Diarrhea or constipation
  • Abdominal swelling
  • Gases.

There are side effects that can cause other more severe symptoms :

  • Fever.
  • Blurry vision.
  • Skin lesions such as rashes, hives, and blisters.
  • Unexplained weight gain.
  • Tachycardia.
  • Fatigue.
  • Difficulty breathing.
  • Swelling of the abdomen and lower limbs.
  • Bleeding or bruising
  • Upset stomach accompanied by loss of appetite.
  • Yellow coloring in eyes and skin.
  • Presence of dark or bloody urine.
  • Difficulty urinating accompanied by pain.

If you’re experiencing these more mefenamic severe acid side effects.

Contraindications of mefenamic acid

Mefenamic acid has the same contraindications as non-steroidal anti-inflammatory drugs, so its administration is not recommended in the following patients. If it is done, it should be done with caution:

  • Gastritis, gastric ulcers, and gastrointestinal bleeding: in these cases, it should be administered with great caution and strict monitoring by your doctor, especially if you smoke or drink alcohol.
  • In people with quagliopathies or those who have hemophilia, it should be placed with caution to avoid alteration of platelet activity and vascular response to bleeding.
  • Patients suffering from liver disease are at increased risk of complications from the consumption of this drug.
  • Patients with kidney and liver disorders, cardiovascular problems, diabetes mellitus, and lupus erythematosus are at high risk of complications.

The following patients should not be administered mefenamic acid under any circumstances:

People allergic to aspirin and NSAIDs

This medicine is not recommended in patients who suffer from hypersensitivity to salicylates or who have presented with the ingestion of aspirin, bronchospasm, angioedema, or shock. There is cross-sensitivity between people allergic to aspirin and NSAIDs.

People with respiratory disorders

People with respiratory disorders such as asthma or polyps in the nasal region are at high risk of suffering from bronchospasm or an allergic reaction when they ingest mefenamic acid. Therefore it should not be administered to these patients.


If you are pregnant, using this drug or non-steroidal anti-inflammatory drugs is not recommended, especially during the second half of pregnancy, because it can cause adverse effects on the fetus, such as platelet, kidney, gastrointestinal disorders, etc. Therefore, its use is limited during the first and second trimesters if strictly necessary.

If you need to take mefenamic acid, go to your trusted doctor: he will indicate if it is appropriate to take this medicine in the face of the symptoms you present. He will also display the recommended dose and the specific time you should assume that medicine.

This article is merely informative. At FastlyHeal .com, we do not have the power to prescribe medical treatments or make any diagnosis. We invite you to see a doctor if you present any condition or discomfort.

If you want to read more articles similar to Mefenamic acid: what it is for, dosage, and side effects, we recommend that you enter our category of Medication and medical tests.

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