backup og meta
Health Screening
Ask Doctor
Table of Content

Ponstan (Mefenamic Acid)

Written by Stephanie Nera, RPh, PharmD · Pharmacology

Updated Jul 01, 2021

Ponstan is the brand name of the generic drug known as mefenamic acid. Mefenamic acid is part of the drug class called nonsteroidal anti-inflammatory drugs (NSAIDs). NSAIDs like mefenamic acid are used to treat mild to moderate pain. Ponstan can be purchased over-the-counter without a prescription.


Know the basics

What is Ponstan used for?

Ponstan is commonly used for treating mild to moderate pain and menstrual pain (dysmenorrhea).

How should I take Ponstan?

Take Ponstan by mouth followed by water, as directed by your doctor. It is best to take it with a meal to avoid stomach discomfort.

How do I store Ponstan?

This product is best stored at room temperature away from direct light and moisture. To prevent drug damage, you should not store it in the bathroom or the freezer. 

There may be different brands of this drug that may have different storage needs. So, it is important to always check the product package for instructions on storage, or ask your pharmacist. For safety, you should keep all medicines away from children and pets.

You should not flush this product down the toilet or pour them into a drain unless instructed to do so. Additionally, it is important to properly discard this product when it is expired or no longer needed. Consult your pharmacist for more details about how to safely discard your product.

Know the precautions & warnings

What should I know before using Ponstan?

Do not use this product if you are/have had:

  • Allergic to any ingredient in Ponstan
  • Severe allergic reactions to other NSAIDs (e.g. ibuprofen, aspirin)
  • Bypass heart surgery
  • Kidney problems, ulcers, or inflammation of the stomach or bowel
  • In the second or third trimester of pregnancy

Consult with your doctor if you are/have:

  • Pregnant, planning to become pregnant, or are breastfeeding
  • Taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
  • Allergies to medicines, foods, or other substances
  • History of liver disease, diabetes, or stomach or bowel problem
  • Swelling or fluid buildup, asthma, nasal polyps, or mouth sores
  • High blood pressure, blood disorders, bleeding or clotting problems, heart problems, or blood vessel disease, or if you are at risk for any of these diseases
  • Poor health, dehydration or low fluid volume, or low blood sodium levels, you drink alcohol, or you have a history of alcohol abuse

Is it safe during pregnancy or breastfeeding?

There are no adequate studies in women for determining risk when using Ponstan during pregnancy or while breastfeeding. Please always consult with your doctor to weigh the potential benefits and risks before taking any drug during pregnancy or lactation.

This drug should not be given to women who are pregnant. It may affect the fetus, especially in the second and third trimester. Additionally, this drug may pass into breastmilk, therefore do not breastfeed while taking this drug.

Know the side effects

What side effects can occur from Ponstan?

Common side effects: stomach pain, nausea, vomiting, heartburn, constipation, diarrhea, rash, dizziness, ringing in your ear (tinnitus).

Serious side effects:

However, not everyone experiences these side effects. In addition, some people may experience other side effects. So, if you have any concerns about a side effect, please consult your doctor or pharmacist.

Know the interactions

What drugs may interact with Ponstan?

Ponstan may interact with other drugs that you are currently taking, which can change how your drug works or increase your risk for serious side effects. To avoid any potential drug interactions, you should keep a list of all the drugs you are using (including prescription drugs, nonprescription drugs, and herbal products) and share it with your doctor and pharmacist. For your safety, do not start, stop, or change the dosage of any drugs without your doctor’s approval.

Drugs with known interactions with Ponstan:

  • ACE inhibitors (e.g. captopril, enalapril)
  • Methotrexate
  • Magnesium hydroxide
  • Lithium
  • Blood thinners (e.g. aspirin, warfarin, coumarin)
  • Diuretics

If you experience an adverse drug interaction, inform your doctor immediately to reevaluate your treatment plan. Approaches include dose adjustment, drug substitution, or ending therapy.

Does food or alcohol interact with Ponstan?

This drug may interact with food or alcohol by altering the way the drug works or increase the risk for serious side effects. Do not consume alcohol while taking this drug. Please discuss with your doctor or pharmacist any potential food or alcohol interactions before using this drug.

What health conditions may interact with Ponstan?

Ponstan may interact with your health condition. This interaction may worsen your health condition or alter the way the drug works. It is important to always let your doctor and pharmacist know all the health conditions you currently have, such as:

  • Liver disease, diabetes, or stomach or bowel problems;
  • History of swelling or fluid buildup, asthma, growths in the nose, or mouth inflammation;
  • High blood pressure, blood disorders, bleeding or clotting problems, heart problems, or blood vessel disease;
  • Low fluid volume, or low blood sodium levels.

Understand the dosage

The information provided is not a substitute for any medical advice. Therefore, you should always consult with your doctor or pharmacist before using any medication.

What is the dose for an adult?

Take 500 mg, three times a day or every 8 hours. Do not take mefenamic acid for more than 7 days.

What is the dose for a child?

Children 14 years and older

Give the same dose as an adult. Do not give mefenamic acid for more than 7 days.

Children 6 months and older

Give 19.5 mg to 25 mg per kg per day, in three divided doses every 8 hours.

Alternatively, you can give suspension doses as follows:

  • 6 months to 1 year: 1 teaspoon (5 mL) three times a day
  • 2 to 4 years: 2 teaspoons (10 mL) three times a day
  • 5 to 8 years: 3 teaspoons (15 mL) three times a day
  • 9 to 14 years: 4 teaspoons (20 mL) three times a day

For rectal suppositories:

  • Age 6 months to 2 years (weighing 10 kg or more): insert 1 suppository every 6 to 8 hours. It is not recommended to give rectal suppositories for more than 1 day.

How is Ponstan available?

Ponstan is available in the following dosage forms and strengths:

  • Capsules: 250 mg (Ponstan), 500 mg (Ponstan SF)/Forte)
  • Tablet :500 mg
  • Suspension: 50 mg/5 mL in bottles of 100 mL, 200 mL, and 2.5 L
  • Rectal suppository: 125 mg

What should I do in case of an emergency or overdose?

In case of an emergency or an overdose, call your local emergency services or go to the nearest emergency room.

What should I do if I miss a dose?

If you miss a dose, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and take your regular dose as scheduled. Do not take a double dose.


Hello Health Group does not provide medical advice, diagnosis or treatment.

Written by

Stephanie Nera, RPh, PharmD


Updated Jul 01, 2021

ad iconadvertisement

Was this article helpful?

ad iconadvertisement
ad iconadvertisement