What should I know about mefenamic acid before taking it?

Before taking mefenamic acid, you should know several things. The most important is that there are many situations in which you should not use this medication. For example, you should not take mefenamic acid if you are allergic to it, any inactive ingredients in mefenamic acid or Ponstel capsules, iodides or any other nonsteroidal anti-inflammatory drug (NSAID). You also should avoid this drug if:

  • you have had recent surgery on the blood vessels of your heart
  • are currently bleeding
  • have kidney disease or a disorder causing ulcers or inflammation in your stomach or intestines
  • are in the last third of your pregnancy
  • are breastfeeding

You should also know that there are many potential side effects of mefenamic acid. Some of the most serious are:

  • severe allergic reactions
  • bleeding, ulcers and/or perforation of the stomach or intestines
  • kidney damage or failure
  • low red blood cell, white blood cell and/or platelet counts
  • prolonged bleeding
  • infection
  • fluid retention
  • congestive heart failure
  • high or low blood pressure
  • irregular heart rhythm
  • heart attack
  • stroke
  • inflammation of blood vessels
  • fainting
  • liver problems
  • wheezing
  • shortness of breath
  • slowing of breathing
  • pneumonia
  • liver failure
  • inflammation of the pancreas
  • seizures
  • depression
  • coma
  • meningitis, severe skin disorders
  • death

You should also be aware that mefenamic acid can interact with several other drugs. When combined with mefenamic acid, blood thinners (such as warfarin) increase the risk of bleeding from the stomach or intestines; aspirin and other salicylates increase the risk of gastrointestinal problems including bleeding; and cyclosporine increases the risk of kidney damage. As well, mefenamic acid may decrease the effectiveness of other drugs, such as water pills and angiotensin-converting enzyme (ACE) inhibitors, or increase the risk of side effects from other drugs, such as lithium and methotrexate.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.