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mefenamic acid

Pronunciation

Generic Name: mefenamic acid (me fe NAM ik)
Brand Name: Ponstel

What is mefenamic acid?

Mefenamic acid is a nonsteroidal anti-inflammatory drug (NSAID). Mefenamic acid works by reducing hormones that cause inflammation and pain in the body.

Mefenamic acid is used short-term (7 days or less) to treat mild to moderate pain in adults and children who are at least 14 years old. Mefenamic acid is also used to treat menstrual pain.

Mefenamic acid may also be used for purposes not listed in this medication guide.

What is the most important information I should know about mefenamic acid?

Mefenamic acid can increase your risk of fatal heart attack or stroke, especially if you use it long term or take high doses, or if you have heart disease. Do not use this medicine just before or after heart bypass surgery (coronary artery bypass graft, or CABG).

Mefenamic acid may also cause stomach or intestinal bleeding, which can be fatal. These conditions can occur without warning while you are using mefenamic acid, especially in older adults.

You should not take mefenamic acid if you already have stomach bleeding or an active ulcer, or a bowel disorder such as ulcerative colitis, or if you have kidney disease.

What should I discuss with my healthcare provider before taking mefenamic acid?

Mefenamic acid can increase your risk of fatal heart attack or stroke, especially if you use it long term or take high doses, or if you have heart disease. Even people without heart disease or risk factors could have a stroke or heart attack while taking this medicine.

Do not use this medicine just before or after heart bypass surgery (coronary artery bypass graft, or CABG).

Mefenamic acid may also cause stomach or intestinal bleeding, which can be fatal. These conditions can occur without warning while you are using mefenamic acid, especially in older adults.

You should not use mefenamic acid if you are allergic to it, or if you have:

  • an active ulcer or stomach bleeding;

  • a bowel disorder such as ulcerative colitis or inflammatory bowel disease;

  • kidney disease; or

  • a history of asthma attack or severe allergic reaction after taking aspirin or an NSAID.

To make sure mefenamic acid is safe for you, tell your doctor if you have:

  • heart disease, high blood pressure, high cholesterol, diabetes, or if you smoke;

  • a history of heart attack, stroke, or blood clot;

  • a history of stomach ulcers or bleeding;

  • asthma;

  • fluid retention; or

  • liver disease.

Taking mefenamic acid during the last 3 months of pregnancy may harm the unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

Mefenamic acid can pass into breast milk and may harm a nursing baby. You should not breast-feed while using this medicine.

Mefenamic acid is not approved for use by anyone younger than 14 years old.

How should I take mefenamic acid?

Follow all directions on your prescription label. Your doctor may occasionally change your dose to make sure you get the best results. Do not take this medicine in larger amounts or for longer than recommended. Use the lowest dose that is effective in treating your condition.

Mefenamic acid should not be used for longer than 7 days. Follow your doctor's dosing instructions very carefully.

If you use this medicine long-term, you may need frequent medical tests.

Mefenamic acid can cause unusual results with certain medical tests. Tell any doctor who treats you that you are using mefenamic acid.

Store at room temperature away from moisture and heat. Keep the bottle tightly closed when not in use.

Read all patient information, medication guides, and instruction sheets provided to you. Ask your doctor or pharmacist if you have any questions.

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking mefenamic acid?

Avoid drinking alcohol. It may increase your risk of stomach bleeding.

Avoid taking aspirin while you are taking mefenamic acid.

Ask a doctor or pharmacist before using any cold, allergy, or pain medication. Many medicines available over the counter contain aspirin or other medicines similar to mefenamic acid. Taking certain products together can cause you to get too much of this type of medication. Check the label to see if a medicine contains aspirin, ibuprofen, ketoprofen, or naproxen.

Mefenamic acid side effects

Get emergency medical help if you have signs of an allergic reaction: sneezing, runny or stuffy nose; wheezing or trouble breathing; hives; swelling of your face, lips, tongue, or throat.

Get emergency medical help if you have signs of a heart attack or stroke: chest pain spreading to your jaw or shoulder, sudden numbness or weakness on one side of the body, slurred speech, feeling short of breath.

Stop using mefenamic acid and call your doctor at once if you have:

  • the first sign of any skin rash, no matter how mild;

  • shortness of breath (even with mild exertion);

  • swelling or rapid weight gain;

  • signs of stomach bleeding--bloody or tarry stools, coughing up blood or vomit that looks like coffee grounds;

  • liver problems--nausea, upper stomach pain, itching, tired feeling, flu-like symptoms, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes);

  • kidney problems--little or no urinating, painful or difficult urination, swelling in your feet or ankles, feeling tired or short of breath;

  • low red blood cells (anemia)--pale skin, feeling light-headed or short of breath, rapid heart rate, trouble concentrating; or

  • severe skin reaction--fever, sore throat, swelling in your face or tongue, burning in your eyes, skin pain followed by a red or purple skin rash that spreads (especially in the face or upper body) and causes blistering and peeling.

Common side effects may include:

  • stomach pain, indigestion, nausea, vomiting;

  • diarrhea, constipation, gas;

  • headache, dizziness;

  • itching, skin rash; or

  • ringing in your ears.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

See also: Side effects (in more detail)

Mefenamic acid dosing information

Usual Adult Dose for Pain:

500 mg orally followed by 250 mg every 6 hours as needed, not to exceed 7 days

Usual Adult Dose for Dysmenorrhea:

500 mg orally followed by 250 mg every 6 hours starting with the onset of menses

Usual Pediatric Dose for Pain:

14 to 18 years: 500 mg orally followed by 250 mg every 6 hours as needed, not to exceed 7 days

What other drugs will affect mefenamic acid?

Ask your doctor before using mefenamic acid if you take an antidepressant such as citalopram, escitalopram, fluoxetine (Prozac), fluvoxamine, paroxetine, sertraline (Zoloft), trazodone, or vilazodone. Taking any of these medicines with an NSAID may cause you to bruise or bleed easily.

Tell your doctor about all your current medicines and any you start or stop using, especially:

  • lithium;

  • methotrexate;

  • antacids such as Milk of Magnesia, Maalox, Mylanta, or Rolaids;

  • a blood thinner (warfarin, Coumadin, Jantoven);

  • heart or blood pressure medication, including a diuretic or "water pill"; or

  • steroid medicine (such as prednisone).

This list is not complete. Other drugs may interact with mefenamic acid, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.

Where can I get more information?

  • Your pharmacist can provide more information about mefenamic acid.
  • Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.
  • Disclaimer: Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2012 Cerner Multum, Inc. Version: 9.01. Revision Date: 2015-09-08, 10:29:12 AM.

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