Ponstan (Mefenamic Acid)

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Ponstan Brand
Dosage Quantity & Price
Mefenamic Acid (Generic alternate to Ponstan) Generic
Dosage Quantity & Price
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Table of contents:

Ponstan is a prescription medication used to relieve moderate to severe pain, inflammation, and fever. Ponstan contains the active ingredient mefenamic acid which belongs to the class of nonsteroidal anti-inflammatory drugs (NSAIDs).

Mefenamic acid works by inhibiting the production of a group of substances in the body called prostaglandins, which are involved in the inflammatory response and responsible for causing pain, fever, and inflammation. By reducing the production of these substances, Ponstan can help relieve pain, inflammation, and fever.

Ponstan is often prescribed to relieve symptoms of menstrual cramps, heavy menstrual bleeding, and pain due to intrauterine devices (IUDs). Other uses for mefenamic acid include treating pain associated with rheumatoid arthritis, osteoarthritis, muscle and joint injuries, and dental pain. More specifically, in the case of menstrual cramps and heavy menstrual bleeding, Ponstan helps by reducing prostaglandins in the lining of the uterus which can cause these symptoms.

Uses and Dosage

Ponstan (Mefenamic Acid) is a tablet that should be taken orally as prescribed by your doctor, typically 4 times daily. It is recommended to take the tablet with a full glass of water (8 ounces/240 milliliters), unless directed otherwise by your doctor. After taking the medication, do not lie down for at least 10 minutes. If you experience stomach upset, taking the medication with food or milk is advised. Avoid taking mefenamic acid with antacids, unless advised otherwise by your doctor, as certain antacids can affect the absorption of the medication.

The dosage and length of treatment are based on your medical condition and response to treatment. To reduce your risk of stomach bleeding and other side effects, take this medication at the lowest effective dose for the shortest possible time. Do not increase your dose or use this drug more often or for longer than prescribed. Ponstan usually should not be taken for more than 7 days at a time.

The standard adult dosage (for individuals aged 14 years or older) for the initial dose is 500 mg, followed by 250 mg every six hours as required, not exceeding a week of therapy. For menstrual cramps, treatment typically does not need to be prolonged for more than two or three days.

Side effect

Common Side Effects of Ponstan (Mefenamic Acid):

  • Constipation
  • Diarrhea
  • Dizziness
  • Gas or bloating
  • Headache
  • Nervousness
  • Ringing in the ears

Serious Side Effects of Ponstan (Mefenamic Acid):

  • Back pain
  • Blisters
  • Blurred vision
  • Cloudy, discolored, or bloody urine
  • Difficult or painful urination
  • Difficulty breathing or swallowing
  • Excessive tiredness
  • Fast heartbeat
  • Fever
  • Flu-like symptoms
  • Hives
  • Itching
  • Lack of energy
  • Loss of appetite
  • Nausea
  • Pain in the upper right part of the stomach
  • Pale skin
  • Rash
  • Shortness of breath or difficulty breathing
  • Swelling of feet, ankles, or lower legs
  • Swelling of the eyes, face, lips, tongue, throat, hands, or arms
  • Unexplained weight gain
  • Unusual bleeding or bruising
  • Yellowing of the skin or eyes

Form and Strength

Plendil is available in the following forms and strength:

Ponstan: Capsule

  • 250 mg

Mefenamic Acid: Capsule

  • 250 mg


  • Like other nonsteroidal anti-inflammatory drugs (NSAIDs), Ponstan can cause stomach irritation and gastrointestinal bleeding. It is important to take the medication with food or milk to reduce the risk of stomach upset.
  • Ponstan can cause or worsen kidney problems, particularly in people who already have kidney disease. It is important to talk to your doctor if you have or have had kidney problems before taking Ponstan.
  • NSAIDs, including Ponstan, can increase the risk of heart attack or stroke, particularly in people who have heart disease or are at risk for it. It is important to discuss with your doctor any heart-related conditions or risks you may have before taking Ponstan.
  • Some people may be allergic to Ponstan or other NSAIDs. It is important to seek medical attention immediately if you experience symptoms of an allergic reaction, such as difficulty breathing, rash, hives, or swelling of the face or throat.
  • Ponstan may not be safe to use during pregnancy or while breastfeeding. Talk to your doctor if you are pregnant or breastfeeding before taking Ponstan.
  • Ponstan may cause or worsen asthma symptoms in some people. Talk to your doctor if you have asthma before taking Ponstan.
  • Ponstan can affect the way blood clots, which can be problematic for people with clotting disorders, such as hemophilia. It is important to discuss any blood clotting disorders with your doctor before taking Ponstan.
  • Ponstan can cause liver damage or worsen existing liver problems. It is important to talk to your doctor before taking Ponstan if you have or have had liver problems in the past.
  • Ponstan can interact with other medications, including blood thinners, antidepressants, and certain blood pressure medications. It is important to talk to your doctor or pharmacist about any medications you are currently taking before taking Ponstan.

 Frequently Asked Questions (FAQ)

How many hours before you take PONSTAN?

The recommended adult dose (for people more than 14 years old) is 500 mg for the first dose followed by 250 mg every six hours as needed, usually not to exceed one week of treatment. In the case of menstrual cramps, treatment is usually not necessary for longer than two or three days.

What should I do if I miss a dose of Ponstan (Mefenamic Acid)?

If you miss a dose of Ponstan, take it as soon as you remember. If it is close to your next scheduled dose, skip the missed dose and resume your regular dosing schedule. Do not double the dose to catch up.

Can I drink Ponstan on an empty stomach?

Take Ponstan with food or immediately after food, to prevent stomach upset. Take your dose with a full glass of water. Swallow the capsules whole and don't crush or chew them.

What should I know about storage and disposal of this medication?

Keep Ponstan in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).


It's important to purchase Ponstan from verified Canadian pharmacy.

Additional information

Generic name:

Mefenamic Acid





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