Mefenamic Acid

1 medicine

Mefenamic acid is an NSAID used mainly for menstrual pain. Like all NSAIDs, it carries a risk of heart attack, stroke and serious stomach bleeding, so it is meant for short courses of no more than 7 days.

Ponstel

Mefenamic acid

250/500mg

Ponstel is a painkillers medication containing Mefenamic acid, available as 250/500mg tablets.

from $0.36 / tablet View

Key facts

  • Mefenamic acid (sold as Ponstan or Ponstel) is an NSAID used mainly for menstrual pain (dysmenorrhea) and other short-term pain.
  • It is normally taken for no more than 7 days at a time, with doses roughly every 6 hours as needed.
  • Like all NSAIDs, it carries a risk of heart attack, stroke and serious stomach bleeding, a risk that rises with higher doses, longer use and existing heart disease.
  • Seek urgent care for chest pain, sudden weakness or slurred speech, vomiting blood, or black, tarry stools.

What mefenamic acid treats

Mefenamic acid treats dysmenorrhea (menstrual cramps) and short-term mild-to-moderate pain, such as dental or musculoskeletal pain. It is not intended for chronic daily use beyond about a week, since the risk of stomach damage rises with prolonged treatment.

How mefenamic acid works

Mefenamic acid blocks cyclooxygenase (COX) enzymes, reducing the body's production of prostaglandins, chemical messengers that cause pain, fever and inflammation.

Before you take it

  • Do not take mefenamic acid if you have had an allergic reaction, including asthma or hives, to aspirin or another NSAID, or around heart bypass surgery.
  • Avoid it in the third trimester of pregnancy: NSAIDs can cause premature narrowing of a fetal blood vessel and reduce amniotic fluid.
  • Tell your prescriber about stomach ulcers, kidney disease, heart disease, high blood pressure, or use of blood thinners, aspirin, steroids or other NSAIDs, since combining these raises bleeding risk.
  • Do not use it for more than 7 days without medical advice; diarrhea can occur with prolonged use.

Side effects

Common effects include stomach upset, diarrhea, headache and dizziness.

Stop and seek urgent medical care for:

  • Vomiting blood or black, tarry stools, which can signal stomach bleeding.
  • Chest pain, sudden weakness or slurred speech, which can signal a heart attack or stroke.
  • Swelling of the face or throat, or difficulty breathing, a sign of a serious allergic reaction.
  • Little or no urination.

Safety essentials

  • Mefenamic acid, like all NSAIDs, can cause a heart attack, stroke or serious stomach bleeding, sometimes without warning symptoms beforehand; use the lowest dose for the shortest time that controls your pain.
  • Do not take it for longer than 7 days, or combine it with other NSAIDs or aspirin, unless your prescriber advises otherwise.
  • Avoid it in the third trimester of pregnancy because of the risk to the fetal heart vessels.

This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.