Mefenamic acid belongs to the class of medications called nonsteroidal anti-inflammatories (NSAIDs). It is used to relieve short-term moderate pain lasting less than one week, such as muscular aches and pains, menstrual cramps, headaches, and dental pain.

Your doctor may have suggested this medication for conditions other than the ones listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

Mefenamic acid is best taken with or after food. The recommended adult dose (for people more than 14 years old) is 500 mg for the first dose followed by 250 mg every six hours as needed, usually not to exceed one week of treatment. In the case of menstrual cramps, treatment is usually not necessary for longer than two or three days.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones given here, do not change the way that you are taking the medication without consulting your doctor.

It is very important that this medication be taken exactly as prescribed by your doctor. If you miss a dose of this medication take it as soon as you remember it. If it is almost time for your next dose, skip the missed dose and carry on with your regular schedule. Do not take a double dose to make up for a missed one.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

Nu-Mefenamic is avialable as a capsule.

250 mg: Type: capsule. Appearance: yellow and blue, opaque. Markings: imprinted "NU 250". Active ingredient: 250 mg of mefenamic acid. Nonmedicinal ingredients: colloidal silcon dioxide, D&C Yellow No. 10, FD&C Blue No. 1, FD&C Yellow No. 6, gelatin, lactose, polysorbate, povidone, stearic acid, titanium dioxide.

This medication does not contain gluten or tartrazine.

This medication should not be taken by anyone who:

• has or recently had an inflammatory condition of the stomach and intestines such as stomach or intestinal ulcer or ulcerative colitis
• is taking other NSAIDs
• is or may be allergic to mefenamic acid or any of the ingredients of the medication
• has had an allergic reaction to ASA or other anti-inflammatory medications
• has a history of significant kidney disease

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent. The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

More common:

• abdominal or stomach cramps, pain, or discomfort (mild-to-moderate)
• diarrhea
• dizziness, drowsiness, or lightheadedness
• headache (mild-to-moderate)
• heartburn, indigestion, nausea, or vomiting

  Less common or rare:

• bitter taste or other change in taste sensation
• bloated feeling, gas, or constipation
• decreased appetite or loss of appetite
• fast or pounding heartbeat
• flushing or hot flashes
• general feeling of discomfort or illness
• increased sensitivity of the eyes to light
• increased sweating
• irritation, dryness, or soreness of the mouth
• nervousness, anxiety, irritability, trembling, or twitching
• rectal irritation (with suppositories)
• trouble sleeping
• unexplained weight loss
• unusual tiredness or weakness without any other symptoms

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

More common:

• bleeding from rectum (with suppositories)
• skin rash

Less common or rare:

bladder pain bleeding from cuts or scratches that lasts longer than usual bleeding or crusting sores on the lips bloody or cloudy urine or any problem with urination, such as difficult, burning, or painful urination change in urine colour or odour frequent urge to urinate sudden, large increase or decrease in the amount of urine or loss of bladder control blurred vision or any change in vision burning feeling in the throat, chest, or stomach confusion, forgetfulness, mental depression, or other mood or mental changes cough or hoarseness decreased hearing, any other change in hearing, or ringing or buzzing in the ears difficulty swallowing eye pain, irritation, dryness, redness, or swelling hallucinations headache (severe), throbbing, or with stiff neck or back

hives, itching of the skin, or any other skin problem (such as blisters, redness or other colour change, tenderness, burning, peeling, loosening or splitting of fingernails) muscle cramps, pain, or weakness numbness, tingling, pain, or weakness in the hands or feet pain in the lower back or side (severe) swelling or tenderness in the upper abdominal or stomach area swelling of the face, feet, or lower legs swelling of the lips or tongue swollen or painful glands (especially in the neck or throat area) thirst (continuing) trouble speaking unexplained runny nose or sneezing unexplained, unexpected, or unusually heavy vaginal bleeding unusual tiredness or weakness weight gain (rapid) yellow eyes or skin

Stop taking this medication and contact your doctor immediately if any of the following side effects occur:

Rare:

• abdominal or stomach pain, cramping, or burning (severe)
• bloody or black, tarry stools
• chest pain
• convulsions (seizures)
• fever with or without chills
• nausea, heartburn, or indigestion (severe and continuing)
• pinpoint-sized red spots on skin
• sores, ulcers, or white spots on the lips or in the mouth
• spitting up of blood
• unexplained nosebleeds
• unusual bleeding or bruising
• vomiting of blood or material that looks like coffee grounds

Stop taking this medication and get emergency help immediately if any of the following side effects occur:

Rare::

• fainting
• fast or irregular breathing
• fast, irregular heartbeat or pulse
• hive-like swellings (large) on the face, eyelids, mouth, lips, or tongue
• puffiness or swelling of the eyelids or around the eyes
• shortness of breath, troubled breathing, wheezing, or tightness in chest

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Asthma: Mefenamic acid should be used with caution in people with asthma.

Diarrhea: If diarrhea occurs, the dosage should be reduced or the medication stopped temporarily. Certain people who develop diarrhea may be unable to tolerate the medication in the future as well.

Gastrointestinal: Stomach ulcers, perforation, and bleeding from the stomach have been known to occur during therapy with mefenamic acid. These complications can occur at any time, and are sometimes severe enough to require immediate medical attention. The risk of ulcers and bleeding increase for people taking higher doses of NSAIDs for longer periods of time. Mefenamic acid may prolong stomach bleeding caused by ASA. However, mefenamic acid itself appears to be less likely than ASA to cause stomach bleeding.

Mefenamic acid should be taken under close medical supervision by people prone to irritation of the stomach and intestines, particularly those who have had a stomach ulcer, bloody stools, or diverticulosis or other inflammatory disease of the stomach or intestines (such as ulcerative colitis or Crohn's disease). In these cases, your doctor must weigh the benefits of treatment against the possible risks.

Stop taking the medication and contact your doctor immediately if you experience symptoms or signs suggestive of stomach ulcers or bleeding in the stomach (black, tarry stools). These reactions can occur at any time during treatment without warning.

Kidney function: Use of mefanamic acid may lead to a higher risk of reduced kidney function. This is most common for people who already have kidney disease, liver disease, or heart failure; for people who take diuretics (water pills); and seniors.

Rash: If a rash occurs, stop taking mefenamic acid immediately.

Pregnancy: This medication is not recommended for use during pregnancy as its safety has not been established.

Breast-feeding: This medication should not be used by nursing mothers.

Children: Mefenamic acid is not recommended for children under the age of 14 years. The safety, effectiveness, and dosages of the medication for this age group have not been established.

Seniors: Seniors appear to have a higher risk of side effects. They should use the lowest effective dosage under close medical supervision.

There may be an interaction between mefenamic acid and any of the following:

• ASA
• alcohol
• angiotensin converting enzyme (ACE) inhibitors (e.g., ramipril)
• beta-adrenergic blockers (e.g., metoprolol, atenolol)
• corticosteroids (e.g., prednisone)
• cyclosporine
• digoxin
• diuretics (water pills; e.g., spironolactone, triamterene)
• heparin
• lithium
• methotrexate
• oral hypoglycemics (anti-diabetes medications, e.g., glyburide)
• other NSAIDs (e.g., naproxen, diclofenac)
• phenytoin
• potassium supplements
• probenecid
• warfarin

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications that you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.