Generic Name: mefenamic acid (me fe NAM ik)Brand Names: Ponstel
Mefenamic acid is in a group of drugs called nonsteroidal anti-inflammatory drugs (NSAIDs). Mefenamic acid works by reducing hormones that cause inflammation and pain in the body.
Mefenamic acid is used to treat pain or inflammation caused by arthritis. It is also used to treat menstrual pain.
Mefenamic acid may also be used for other purposes not listed in this medication guide.
This medicine can increase your risk of life-threatening heart or circulation problems, including heart attack or stroke. Do not use this medicine just before or after having heart bypass surgery (also called coronary artery bypass graft, or CABG).
Seek emergency medical help if you have symptoms of heart or circulation problems, such as chest pain, weakness, shortness of breath, slurred speech, or problems with vision or balance.
This medicine can also increase your risk of serious effects on the stomach or intestines, including bleeding or perforation (forming of a hole). These conditions can be fatal and gastrointestinal effects can occur without warning at any time while you are taking mefenamic acid. Older adults may have an even greater risk of these serious gastrointestinal side effects.
Call your doctor at once if you have symptoms of bleeding in your stomach or intestines. This includes black, bloody, or tarry stools, or coughing up blood or vomit that looks like coffee grounds.
Taking an NSAID can increase your risk of life-threatening heart or circulation problems, including heart attack or stroke. This risk will increase the longer you use an NSAID. Do not use this medicine just before or after having heart bypass surgery (also called coronary artery bypass graft, or CABG).
NSAIDs can also increase your risk of serious effects on the stomach or intestines, including bleeding or perforation (forming of a hole). These conditions can be fatal and gastrointestinal effects can occur without warning at any time while you are taking an NSAID. Older adults may have an even greater risk of these serious gastrointestinal side effects.Do not use this medication if you are allergic to mefenamic acid, aspirin, or other NSAIDs.
If you have any of these other conditions, you may need a dose adjustment or special tests to safely use this medication:
a history of heart attack, stroke, or blood clot;
heart disease, congestive heart failure, high blood pressure;
polyps in your nose; or
if you smoke.
Take this medication exactly as it was prescribed for you. Do not take the medication in larger amounts, or take it for longer than recommended by your doctor. Follow the directions on your prescription label.
If you take mefenamic acid for a long period of time, your doctor may want to check you on a regular basis to make sure this medication is not causing harmful effects. Do not miss any scheduled visits to your doctor.Store mefenamic acid at room temperature, away from moisture, heat, and light.
See also: Mefenamic acid dosage in more detail
Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and take the medicine at your next regularly scheduled time. Do not take extra medicine to make up the missed dose.
chest pain, weakness, shortness of breath, slurred speech, problems with vision or balance;
black, bloody, or tarry stools, coughing up blood or vomit that looks like coffee grounds;
urinating less than usual or not at all;
pain, burning, or bleeding when you urinate;
nausea, stomach pain, low fever, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes);
fever, sore throat, and headache with a severe blistering, peeling, and red skin rash; or
bruising, severe tingling, numbness, pain, muscle weakness.
Less serious side effects may include:
upset stomach, mild heartburn or stomach pain, diarrhea, constipation; bloating, gas;
dizziness, headache, nervousness;
skin itching or rash;
increased sweating, runny nose;
blurred vision; 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.
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
Tell your doctor if you are taking an antidepressant such as citalopram (Celexa), duloxetine (Cymbalta), escitalopram (Lexapro), fluoxetine (Prozac, Sarafem, Symbyax), fluvoxamine (Luvox), paroxetine (Paxil), sertraline (Zoloft), or venlafaxine (Effexor). Taking any of these drugs with mefenamic acid may cause you to bruise or bleed easily.
Before taking mefenamic acid, tell your doctor if you are taking any of the following drugs:
a blood thinner such as warfarin (Coumadin;
a diuretic (water pill) such as furosemide (Lasix);
cyclosporine (Gengraf, Neoral, Sandimmune);
lithium (Eskalith, Lithobid);
methotrexate (Rheumatrex, Trexall);
steroids (prednisone and others); or
aspirin or NSAIDs (non-steroidal anti-inflammatory drugs) such as diclofenac (Voltaren), etodolac (Lodine), fenoprofen (Nalfon), flurbiprofen (Ansaid), ibuprofen (Advil, Motrin), indomethacin (Indocin), ketoprofen (Orudis), ketorolac (Toradol), meclofenamate (Meclomen), meloxicam (Mobic), nabumetone (Relafen), naproxen (Aleve, Naprosyn), piroxicam (Feldene), and others.
This list is not complete and there may be other drugs that can interact with mefenamic acid. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor.