Description and Brand Names

Drug information provided by: Merative, Micromedex®

US Brand Name

  1. Ponstel

Descriptions


Mefenamic acid is a nonsteroidal anti-inflammatory drug (NSAID) used to treat mild to moderate pain. It may also be used to treat menstrual cramps and other conditions as determined by your doctor.

This medicine is available only with your doctor's prescription.

This product is available in the following dosage forms:

  • Capsule

Before Using

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Allergies

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Pediatric

Appropriate studies have not been performed on the relationship of age to the effects of mefenamic acid in children below 14 years of age. Safety and efficacy have not been established.

Geriatric

Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of mefenamic acid in the elderly. However, elderly patients are more likely to have age-related kidney problems, which may require caution and an adjustment in the dose for patients receiving mefenamic acid.

Breastfeeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Drug Interactions

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.

  • Ketorolac

Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

  • Abciximab
  • Aceclofenac
  • Acemetacin
  • Acenocoumarol
  • Aluminum Carbonate, Basic
  • Aluminum Hydroxide
  • Aluminum Phosphate
  • Amifampridine
  • Amiloride
  • Amineptine
  • Amitriptyline
  • Amitriptylinoxide
  • Amoxapine
  • Amtolmetin Guacil
  • Anagrelide
  • Apixaban
  • Ardeparin
  • Argatroban
  • Aspirin
  • Balsalazide
  • Bemetizide
  • Bemiparin
  • Bendroflumethiazide
  • Benzthiazide
  • Betrixaban
  • Bismuth Subsalicylate
  • Bivalirudin
  • Bromfenac
  • Budesonide
  • Bufexamac
  • Bumetanide
  • Bupropion
  • Calcium Carbonate
  • Cangrelor
  • Celecoxib
  • Certoparin
  • Chlorothiazide
  • Chlorthalidone
  • Choline Magnesium Trisalicylate
  • Choline Salicylate
  • Cilostazol
  • Citalopram
  • Clomipramine
  • Clonixin
  • Clopamide
  • Clopidogrel
  • Cyclopenthiazide
  • Cyclosporine
  • Cyclothiazide
  • Dabigatran Etexilate
  • Dalteparin
  • Danaparoid
  • Deflazacort
  • Desipramine
  • Desirudin
  • Desmopressin
  • Desvenlafaxine
  • Dexamethasone
  • Dexibuprofen
  • Dexketoprofen
  • Diazoxide
  • Dibenzepin
  • Diclofenac
  • Diflunisal
  • Digoxin
  • Dihydroxyaluminum Aminoacetate
  • Dihydroxyaluminum Sodium Carbonate
  • Dipyridamole
  • Dipyrone
  • Donepezil
  • Dothiepin
  • Doxepin
  • Droxicam
  • Duloxetine
  • Edoxaban
  • Emtricitabine
  • Enoxaparin
  • Eplerenone
  • Epoprostenol
  • Eptifibatide
  • Escitalopram
  • Ethacrynic Acid
  • Etodolac
  • Etofenamate
  • Etoricoxib
  • Etozolin
  • Felbinac
  • Fenoprofen
  • Fepradinol
  • Feprazone
  • Feverfew
  • Floctafenine
  • Flufenamic Acid
  • Fluoxetine
  • Flurbiprofen
  • Fluvoxamine
  • Fondaparinux
  • Furosemide
  • Ginkgo
  • Gossypol
  • Heparin
  • Hydrochlorothiazide
  • Hydrocortisone
  • Hydroflumethiazide
  • Ibuprofen
  • Iloprost
  • Imipramine
  • Indapamide
  • Indomethacin
  • Inotersen
  • Ketoprofen
  • Lepirudin
  • Levoketoconazole
  • Levomilnacipran
  • Lithium
  • Lofepramine
  • Lornoxicam
  • Loxoprofen
  • Lumiracoxib
  • Magaldrate
  • Magnesium Carbonate
  • Magnesium Hydroxide
  • Magnesium Oxide
  • Magnesium Salicylate
  • Magnesium Trisilicate
  • Meadowsweet
  • Meclofenamate
  • Melitracen
  • Meloxicam
  • Melphalan
  • Mesalamine
  • Methotrexate
  • Methyclothiazide
  • Methylprednisolone
  • Metolazone
  • Milnacipran
  • Morniflumate
  • Nabumetone
  • Nadroparin
  • Naproxen
  • Nefazodone
  • Nepafenac
  • Niflumic Acid
  • Nimesulide
  • Nimesulide Beta Cyclodextrin
  • Nortriptyline
  • Olsalazine
  • Opipramol
  • Oxaprozin
  • Oxyphenbutazone
  • Parecoxib
  • Parnaparin
  • Paroxetine
  • Pemetrexed
  • Pentosan Polysulfate Sodium
  • Pentoxifylline
  • Phenindione
  • Phenprocoumon
  • Phenylbutazone
  • Phenyl Salicylate
  • Piketoprofen
  • Piretanide
  • Piroxicam
  • Polythiazide
  • Potassium Citrate
  • Prasugrel
  • Prednisolone
  • Prednisone
  • Proglumetacin
  • Propyphenazone
  • Proquazone
  • Protein C
  • Protriptyline
  • Quinethazone
  • Reviparin
  • Rivaroxaban
  • Rofecoxib
  • Salicylamide
  • Salicylic Acid
  • Salsalate
  • Selexipag
  • Sertraline
  • Sibutramine
  • Sodium Bicarbonate
  • Sodium Salicylate
  • Spironolactone
  • Sulfasalazine
  • Sulfinpyrazone
  • Sulindac
  • Sulodexide
  • Tacrolimus
  • Tenofovir Alafenamide
  • Tenofovir Disoproxil Fumarate
  • Tenoxicam
  • Tianeptine
  • Tiaprofenic Acid
  • Ticagrelor
  • Ticlopidine
  • Tinzaparin
  • Tirofiban
  • Tolfenamic Acid
  • Tolmetin
  • Torsemide
  • Trazodone
  • Treprostinil
  • Triamterene
  • Trichlormethiazide
  • Trimipramine
  • Trolamine Salicylate
  • Valdecoxib
  • Venlafaxine
  • Vilazodone
  • Vorapaxar
  • Vortioxetine
  • Warfarin
  • Xipamide

Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

  • Acebutolol
  • Atenolol
  • Azilsartan
  • Azilsartan Medoxomil
  • Benazepril
  • Betaxolol
  • Bisoprolol
  • Candesartan
  • Captopril
  • Carteolol
  • Carvedilol
  • Celiprolol
  • Enalapril
  • Enalaprilat
  • Eprosartan
  • Esmolol
  • Fosinopril
  • Irbesartan
  • Labetalol
  • Levobunolol
  • Lisinopril
  • Losartan
  • Metipranolol
  • Metoprolol
  • Moexipril
  • Nadolol
  • Nebivolol
  • Olmesartan
  • Oxprenolol
  • Penbutolol
  • Perindopril
  • Pindolol
  • Propranolol
  • Quinapril
  • Ramipril
  • Sotalol
  • Spirapril
  • Telmisartan
  • Timolol
  • Trandolapril
  • Valsartan

Other Interactions

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other Medical Problems

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

  • Anemia or
  • Asthma or
  • Bleeding problems or
  • Blood clots or
  • Congestive heart failure or
  • Edema (fluid retention or body swelling) or
  • Heart attack, history of or
  • Hyperkalemia (high potassium in the blood) or
  • Hypertension (high blood pressure) or
  • Kidney disease or
  • Liver disease (eg, hepatitis) or
  • Stomach or intestinal ulcers or bleeding, history of or
  • Stroke, history of—Use with caution. May make these conditions worse.
  • Aspirin-sensitive asthma, history of or
  • Aspirin (or other NSAIDs) sensitivity, history of or
  • Kidney disease, severe or
  • Stomach ulcers, active—Should not be used in patients with these conditions.
  • Dehydration or
  • Hypovolemia (low blood volume)—Must be corrected first before using this medicine.
  • Heart surgery (eg, coronary artery bypass graft [CABG] surgery)—Should not be used for pain right before or after surgery.

Proper Use

Take this medicine only as directed by your doctor. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered. To do so may increase the chance for side effects.

This medicine should come with a Medication Guide. Read and follow these instructions carefully. Ask your doctor or pharmacist if you have any questions.

If this medicine upsets your stomach, take it with food or milk.

Dosing

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For oral dosage form (capsules):
    • For menstrual cramps:
      • Adults and children 14 years of age and older—At first, 500 milligrams (mg), then 250 mg every 6 hours as needed, for 2 to 3 days.
      • Children younger than 14 years of age—Use and dose must be determined by your doctor.
    • For mild to moderate pain:
      • Adults and children 14 years of age and older—At first, 500 milligrams (mg), then 250 mg every 6 hours as needed, for not more than 1 week.
      • Children younger than 14 years of age—Use and dose must be determined by your doctor.

Missed Dose

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.

Precautions

It is very important that your doctor check your progress at regular visits. to make sure this medicine is working properly. Blood and urine tests may be needed to check for unwanted effects.

This medicine may raise your risk of having a heart attack or stroke. This is more likely in people who already have heart disease or in people who use this medicine for a long time. Check with your doctor right away if you are having chest pain or discomfort, nausea or vomiting, pain or discomfort in the arms, jaw, back, or neck, trouble breathing, slurred speech, or weakness.

This medicine may cause bleeding in your stomach or intestines. These problems can happen without warning signs. This is more likely if you have had a stomach ulcer in the past, if you smoke or drink alcohol regularly, are over 60 years of age, are in poor health, or using certain other medicines (eg, steroid medicine, blood thinner).

Check with your doctor right away if you have pain or tenderness in the upper stomach, pale stools, dark urine, loss of appetite, nausea, vomiting, or yellow eyes or skin. These could be symptoms of a serious liver problem.

Serious skin reactions, including exfoliative dermatitis, Stevens-Johnson syndrome, toxic epidermal necrolysis, and drug reaction with eosinophilia and systemic symptoms (DRESS) can occur with this medicine. Check with your doctor right away if you have black, tarry stools, blistering, peeling, or loosening of the skin, chest pain, chills, cough, diarrhea, fever, itching, joint or muscle pain, painful or difficult urination, red irritated eyes, red skin lesions, sore throat, sores, ulcers, or white spots in the mouth or on the lips, swollen glands, unusual bleeding or bruising, or unusual tiredness or weakness.

Some possible warning signs of some serious side effects that can occur during treatment with this medicine may include swelling of the face, fingers, feet, or lower legs, severe stomach pain, black, tarry stools, or vomiting of blood or material that looks like coffee grounds, unusual weight gain, yellow skin or eyes, decreased urination, bleeding or bruising, or skin rash. Also, signs of serious heart problems could occur including chest pain or tightness, fast or irregular heartbeat, unusual flushing or warmth of skin, weakness, or slurring of speech. Check with your doctor immediately if you notice any of these warning signs.

Check with your doctor right away if you have bloody urine, a decrease in frequency or amount of urine, an increase in blood pressure, increased thirst, loss of appetite, lower back or side pain, nausea, swelling of the face, fingers, or lower legs, trouble breathing, unusual tiredness or weakness, vomiting, or weight gain. These could be symptoms of a serious kidney problem.

Hyperkalemia (high potassium in the blood) may occur while you are using this medicine. Check with your doctor right away if you have stomach pain, confusion, difficulty with breathing, irregular heartbeat, nausea or vomiting, nervousness, numbness or tingling in the hands, feet, or lips, or weakness or heaviness of the legs.

This medicine may cause a serious allergic reaction called anaphylaxis, which can be life-threatening and requires immediate medical attention. Tell your doctor right away if you have a rash, itching, hoarseness, trouble breathing, trouble swallowing, or any swelling of your hands, face, or mouth after using this medicine.

This medicine may cause a delay in ovulation for women and may affect their ability to have children. If you plan to have children, talk with your doctor before using this medicine.

Using this medicine during the later part of a pregnancy can harm your unborn baby. If you think you have become pregnant while using this medicine, tell your doctor right away.

Make sure any doctor or dentist who treats you knows that you are using this medicine. This medicine may affect the results of certain medical tests.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Side Effects

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

More common

  1. Bloody urine
  2. bloody, black, or tarry stools
  3. decreased frequency or amount of urine
  4. heartburn
  5. increased bleeding time
  6. increased blood pressure
  7. increased thirst
  8. indigestion
  9. itching, skin rash
  10. loss of appetite
  11. lower back or side pain
  12. nausea
  13. pale skin
  14. severe stomach pain, cramping, or burning
  15. stomach bloating
  16. swelling of the face, fingers, feet, or lower legs
  17. trouble breathing
  18. unusual bleeding or bruising
  19. unusual tiredness or weakness
  20. vomiting
  21. vomiting of material that looks like coffee grounds, severe and continuing
  22. weight gain
  23. weight loss

Less common

  1. Bleeding gums
  2. blood in vomit
  3. blurred vision
  4. burning feeling in the chest or stomach
  5. chest pain or tightness
  6. clay-colored stools
  7. cloudy urine
  8. confusion
  9. constipation
  10. cough or hoarseness
  11. dark urine
  12. difficult or labored breathing
  13. difficult, burning, or painful urination
  14. difficulty in swallowing
  15. dilated neck veins
  16. dizziness
  17. fainting
  18. fast, pounding, or irregular heartbeat or pulse
  19. fever or chills
  20. frequent urge to urinate
  21. headache
  22. increased volume of pale, dilute urine
  23. irregular, rapid, or slow breathing
  24. irregular heartbeat
  25. large, flat, blue, or purplish patches in the skin
  26. light-colored stools
  27. lightheadedness
  28. nervousness
  29. noisy breathing
  30. pain or burning feeling in the throat
  31. pinpoint red or purple spots on the skin
  32. pounding in the ears
  33. redness, swelling, or soreness of the tongue
  34. severe or continuing stomach pain
  35. slow heartbeat
  36. sore throat
  37. sores, ulcers, or white spots on the lips or tongue or inside the mouth
  38. stomach upset
  39. swelling or inflammation of the mouth
  40. swollen glands
  41. tenderness in the stomach area
  42. tremors
  43. unpleasant breath odor
  44. upper right stomach pain
  45. yellow eyes and skin

Rare

  1. Blistering, peeling, or loosening of the skin
  2. change in consciousness
  3. chest discomfort
  4. continuing vomiting
  5. cracks in the skin
  6. diarrhea
  7. dizziness, faintness, or lightheadedness when suddenly getting up from a lying or sitting position
  8. drowsiness
  9. fever with or without chills
  10. flushed, dry skin
  11. fruit-like breath odor
  12. general body swelling
  13. general feeling of illness
  14. high fever
  15. hives
  16. increased hunger
  17. joint or muscle pain
  18. large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
  19. leg pain
  20. loss of consciousness
  21. loss of heat from the body
  22. no blood pressure
  23. no breathing
  24. no pulse
  25. nosebleeds
  26. painful glands
  27. pain or discomfort in the arms, jaw, back, or neck
  28. pains in the stomach, side, or abdomen, possibly radiating to the back
  29. pale or blue lips, fingernails, or skin
  30. puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
  31. racing heartbeat or pulse
  32. red skin lesions, often with a purple center
  33. red, irritated eyes
  34. red, swollen skin
  35. redness or soreness of the skin
  36. scaly skin
  37. seeing, hearing, or feeling things that are not there
  38. seizures
  39. severe headache
  40. sneezing
  41. sores, welting, or blisters
  42. stiff neck or back
  43. sweating
  44. swollen, painful, or tender lymph glands in the neck, armpit, or groin
  45. unexplained weight loss

Get emergency help immediately if any of the following symptoms of overdose occur:

Symptoms of overdose

  1. Unusual drowsiness, dullness, tiredness, weakness, or feeling of sluggishness

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

  1. Continuing ringing or buzzing or other unexplained noise in the ears
  2. excess air or gas in the stomach or intestines
  3. feeling of fullness
  4. hearing loss
  5. passing gas
  6. stomach discomfort

Less common

  1. Burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
  2. discouragement
  3. dry mouth
  4. fear
  5. feeling of constant movement of self or surroundings
  6. feeling sad or empty
  7. hair loss, thinning of the hair
  8. increased sensitivity of the skin to sunlight
  9. irritability
  10. lack of appetite
  11. lack of interest or pleasure
  12. lack or loss of strength
  13. redness or other discoloration of the skin
  14. sensation of spinning
  15. severe sunburn
  16. sleepiness
  17. trouble concentrating
  18. trouble sleeping

Rare

  1. Appetite changes
  2. burning, dry, or itching eyes
  3. change in hearing
  4. discharge, excessive tearing
  5. redness, pain, swelling of the eye, eyelid, or inner lining of the eyelid

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Portions of this document last updated: April 01, 2024

Original article: https://www.mayoclinic.org/drugs-supplements/mefenamic-acid-oral-route/side-effects/drg-20070790