Mefenamic Acid

Conditions Treated

Mefenamic acid is used to relieve mild to moderate pain, including menstrual pain (pain that happens before or during a menstrual period). Mefenamic acid is in a class of medications called NSAIDs. It works by stopping the body's production of a substance that causes pain, fever, and inflammation.

Possible Side Effects

What Side Effects Can This Cause?

Mefenamic acid may cause side effects. Inform your doctor if any of these symptoms are severe or do not go away:

• diarrhea
• constipation
• gas or bloating
• headache
• dizziness
• nervousness
• ringing in the ears

Some side effects can be serious. If you experience any of the following symptoms or those mentioned in the IMPORTANT WARNING section, call your doctor immediately. Do not take any more mefenamic acid until you speak to your doctor.

• blurred vision
• unexplained weight gain
• fever
• blisters
• rash
• itching
• hives
• swelling of the eyes, face, lips, tongue, throat, hands, arms, feet ankles, or lower legs
• difficulty breathing or swallowing
• pale skin
• fast heartbeat
• excessive tiredness
• unusual bleeding or bruising
• lack of energy
• nausea
• loss of appetite
• pain in the upper right part of the stomach
• flu-like symptoms
• yellowing of the skin or eyes
• cloudy, discolored, or bloody urine
• back pain
• difficult or painful urination

Usage Instructions

How Should This Medication Be Used

Mefenamic acid comes as a capsule to take by mouth. It is usually taken with food every 6 hours as needed for up to 1 week. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take mefenamic acid exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

What Dietary Instructions Should I Follow

Unless your doctor tells you otherwise, continue your normal diet.

Are There Any Special Instructions

Before taking mefenamic acid, tell your doctor and pharmacist if you are allergic to mefenamic acid, aspirin or other NSAIDs such as ibuprofen (Advil, Motrin) and naproxen (Aleve, Naprosyn), any other medications, or any of the inactive ingredients in mefenamic acid capsules. Ask your pharmacist for a list of the inactive ingredients. tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention the medications listed in the IMPORTANT WARNING section and any of the following: antacids; angiotensin-converting enzyme (ACE) inhibitors such as benazepril (Lotensin), captopril (Capoten), enalapril (Vasotec), fosinopril (Monopril), lisinopril (Prinivil, Zestril), moexipril (Univasc), perindopril (Aceon), quinapril (Accupril), ramipril (Altace), and trandolapril (Mavik); amiodarone (Cordarone, Pacerone); atazanavir (Reyataz); clopidogrel (Plavix); diuretics ('water pills'), efavirenz (Sustiva); fluconazole (Diflucan); fluvastatin (Lescol); metronidazole (Flagyl); lithium (Eskalith, Lithobid); lovastatin (Mevacor); methotrexate (Rheumatrex); ritonavir (Norvir, in Kaletra); sulfamethoxazole (in Bactrim, in Septra); sulfinpyrazone (Anturane); trimethoprim (Proloprim); and zafirlukast (Accolate). Your doctor may need to change the doses of your medications or monitor you more carefully for side effects. tell your doctor if you have or have ever had any of the conditions mentioned in the IMPORTANT WARNING section or asthma, especially if you also have frequent stuffed or runny nose or nasal polyps (swelling of the inside of the nose); swelling of the hands, feet, ankles, or lower legs (fluid retention); or liver or kidney disease. if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking mefenamic acid.