Before you begin taking 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 take Mefenamic (Mefenamic-acid).
HEALTH CANADA ADVISORY
June 8, 2021
Health Canada has issued new information concerning the use of non-steroidal anti-inflammatory drugs (NSAIDs). To read the full Health Canada Advisory, visit Health Canada's web site at www.hc-sc.gc.ca.
A previous advisory on non-steroidal anti-inflammatory drugs (NSAIDs) was issued on October 30, 2020.
Allergy: Some people who are allergic to other NSAIDs or ASA also experience allergic reactions to mefenamic acid. Before you take mefenamic acid, inform your doctor about any previous adverse reactions you have had to medications, especially NSAIDs. People who have experienced difficulty breathing after taking ASA or other NSAIDs should not take mefenamic acid.
Contact your doctor at once if you experience signs of an allergic reaction, such as skin rash, itching, difficulty breathing or swelling of the face and throat.
Anemia: Mefenamic (Mefenamic-acid) may cause anemia (low red blood cells). If you take Mefenamic (Mefenamic-acid) for a long period of time, your doctor will periodically monitor your red blood cell levels. If you experience symptoms of anemia (e.g., shortness of breath, fatigue, pallor, fast heartbeat), contact your doctor as soon as possible.
Asthma: People with asthma are at increased risk of severe and even fatal allergic reactions (Anaphylaxis (severe allergic reaction)) when taking Mefenamic (Mefenamic-acid). People with asthma or other breathing disorders should discuss with their doctor how Mefenamic (Mefenamic-acid) may affect their medical condition, how their medical condition may affect the dosing and effectiveness of Mefenamic (Mefenamic-acid), and whether any special monitoring is needed.
Bleeding disorders: Mefenamic acid may increase bruising and bleeding from cuts may take longer to stop. People with bleeding disorders, a history of bleeding problems, or those who are taking medications to prevent clotting, should discuss with their doctor how Mefenamic (Mefenamic-acid) may affect their medical condition, how their medical condition may affect the dosing and effectiveness of Mefenamic (Mefenamic-acid), and whether any special monitoring is needed.
Blood pressure: Mefenamic acid may cause an increase in blood pressure, even when there have been no blood pressure problems in the past. People with high blood pressure should discuss with their doctor how Mefenamic (Mefenamic-acid) may affect their medical condition, how their medical condition may affect the dosing and effectiveness of Mefenamic (Mefenamic-acid) and whether any special monitoring is needed. Report any ongoing increase in blood pressure to your doctor as soon as possible.
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.
Fluid retention: Mefenamic acid can cause fluid retention and may result in swelling or puffiness. In severe cases, this can make symptoms of Congestive Heart Failure worse. People with congestive heart failure should discuss with their doctor how Mefenamic (Mefenamic-acid) may affect their medical condition, how their medical condition may affect the dosing and effectiveness of Mefenamic (Mefenamic-acid) and whether any special monitoring is needed.
Report any fluid retention, swelling or puffiness in the legs, feet or hands, or any difficulty breathing, to your doctor as soon as possible.
Heart problems: Mefenamic acid, like other NSAIDs, may increase the risk of serious heart problems such as Heart Attack, Stroke, or Blood Clots. People who are at risk for heart disease, such as high blood pressure, High Cholesterol, Diabetes, or pre-existing heart disease, should discuss with their doctor how Mefenamic (Mefenamic-acid) may affect their medical condition, how their medical condition may affect the dosing and effectiveness of Mefenamic (Mefenamic-acid) and whether any special monitoring is needed.
Kidney function: Long term use of mefenamic 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.
People with kidney disease or reduced kidney function should discuss with their doctor how Mefenamic (Mefenamic-acid) may affect their medical condition, how their medical condition may affect the dosing and effectiveness of Mefenamic (Mefenamic-acid), and whether any special monitoring is needed.
Liver function: People with liver disease or reduced liver function should discuss with their doctor how Mefenamic (Mefenamic-acid) may affect their medical condition, how their medical condition may affect the dosing and effectiveness of Mefenamic (Mefenamic-acid), and whether any special monitoring is needed.
If you experience symptoms of liver problems such as fatigue, feeling unwell, loss of appetite, nausea, yellowing of the skin or whites of the eyes, dark urine, pale stools, abdominal pain or swelling, and itchy skin, contact your doctor immediately.
Stomach problems: 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 increases when higher doses of NSAIDs are taken 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.
People who easily experience irritation of the stomach and intestines, have had a stomach ulcer in the past or have another inflammatory disease of the stomach such as ulcerative colitis or Crohn's Disease, should discuss with their doctor how Mefenamic (Mefenamic-acid) may affect their medical condition, how their medical condition may affect the dosing and effectiveness of Mefenamic (Mefenamic-acid) and whether any special monitoring is needed.
Stop taking the medication and contact your doctor immediately if you experience symptoms or signs that suggest stomach ulcers or bleeding in the stomach (black, tarry stools). These reactions can occur at any time during treatment without warning.
Pregnancy: Mefenamic (Mefenamic-acid) should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking Mefenamic (Mefenamic-acid), contact your doctor immediately.
The use of mefenamic acid during the last 3 months of pregnancy may result in harm to the baby or longer labour for the mother. Mefenamic acid should not be used during this time.
Breast-feeding: Mefenamic (Mefenamic-acid) passes into breast milk. If you are a breast-feeding mother and are taking mefenamic acid, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.
Children: Mefenamic acid is not recommended for children under the age of 18 years. The safety and effectiveness of using Mefenamic (Mefenamic-acid) have not been established for children.
Seniors: Seniors appear to have a higher risk of side effects, such as bleeding and kidney problems. The lowest effective dosage should be used for the shortest period of time possible.
