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Mefenamic Acid

Warning

Nonsteroidal anti-inflammatory drugs (including mefenamic acid) may rarely increase the risk of a heart attack or stroke. This effect can happen at any time while taking this drug but is more likely if you take it for a long time. The risk may be greater in older adults or if you have heart disease or increased risk for heart disease (for example, due to smoking, family history of heart disease, or conditions such as high blood pressure or diabetes). Do not take this drug right before or after heart bypass surgery (CABG).

Also, this drug may rarely cause serious (rarely fatal) bleeding from the stomach or intestines. This effect can occur without warning symptoms at any time while taking this drug. Older adults may be at higher risk for this effect.

Stop taking mefenamic acid and get medical help right away if you notice any of these rare but serious side effects: stomach/abdominal pain that doesn't go away, black/tarry stools, vomit that looks like coffee grounds, chest/jaw/left arm pain, shortness of breath, unusual sweating, confusion, weakness on one side of the body, trouble speaking, sudden vision changes.

Talk to your doctor or pharmacist about the benefits and risks of taking this drug.

Precautions

See also Warning section.

Before taking mefenamic acid, tell your doctor or pharmacist if you are allergic to it; or to aspirin or other NSAIDs (such as ibuprofen, naproxen, celecoxib); or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: asthma (including a history of worsening breathing after taking aspirin or other NSAIDs), bleeding/clotting problems, blood disorders (such as anemia), growths in the nose (nasal polyps), heart disease (such as previous heart attack), high blood fat levels (cholesterol/triglyceride), high blood pressure, liver disease, stroke, swelling (edema, fluid retention), stomach/intestinal/esophagus problems (such as bleeding, heartburn, ulcers).

Kidney problems can sometimes occur with the use of NSAID medications, including mefenamic acid. Problems are more likely to occur if you are dehydrated, have heart failure or kidney disease, are an older adult, or if you take certain medications (see also Drug Interactions section). Drink plenty of fluids as directed by your doctor to prevent dehydration and tell your doctor right away if you have pink/bloody urine or any unusual change in the amount of urine.

This drug may make you dizzy, drowsy, or cause blurred vision. Alcohol or marijuana (cannabis) can worsen these effects. Do not drive, use machinery, or do anything that needs alertness or clear vision until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).

This medicine may cause stomach bleeding. Daily use of alcohol and tobacco, especially when combined with this medicine, may increase your risk for stomach bleeding. Limit alcohol and stop smoking. Ask your doctor or pharmacist about how much alcohol you may safely drink.

This medication may make you more sensitive to the sun. Limit your time in the sun. Avoid tanning booths and sunlamps. Use sunscreen and wear protective clothing when outdoors. Tell your doctor right away if you get sunburned or have skin blisters/redness.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Older adults may be at greater risk for stomach/intestinal bleeding, kidney problems, heart attack, and stroke while using this drug.

Before using this medication, women of childbearing age should talk with their doctor(s) about the benefits and risks. Tell your doctor if you are pregnant or if you plan to become pregnant. This medication may harm an unborn baby and cause problems with normal labor/delivery. It is not recommended for use in pregnancy from 20 weeks until delivery. If your doctor decides that you need to use this medication between 20 and 30 weeks of pregnancy, you should use the lowest effective dose for the shortest possible time. You should not use this medication after 30 weeks of pregnancy.

This drug passes into breast milk. Consult your doctor before breastfeeding.

Side Effects

See also Warning section.

Upset stomach, nausea, diarrhea, dizziness, drowsiness, or blurred vision may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

This medication may raise your blood pressure. Check your blood pressure regularly and tell your doctor if the results are high.

Tell your doctor right away if you have any serious side effects, including: hearing changes (such as ringing in the ears), mental/mood changes, easy bleeding/bruising, difficult/painful swallowing, signs of kidney problems (such as change in the amount of urine, pink/bloody urine), symptoms of heart failure (such as swelling ankles/feet, unusual tiredness, unusual/sudden weight gain).

Mefenamic acid may rarely cause serious (possibly fatal) liver disease. Get medical help right away if you have any symptoms of liver damage, including: nausea/vomiting that doesn't stop, loss of appetite, stomach/abdominal pain, yellowing eyes/skin, dark urine.

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: fever, swollen lymph nodes, rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.