Ponstan

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How does it work?

Ponstan capsules contain the active ingredient mefenamic acid, which is a type of medicine called a non-steroidal anti-inflammatory drug (NSAID). NSAIDs are used to relieve pain and inflammation. (NB. Mefenamic acid is also available without a brand name, ie as the generic medicine.)

Mefenamic acid works by blocking the action of a substance in the body called cyclo-oxygenase (COX). Cyclo-oxygenase is involved in the production of various chemicals in the body, some of which are known as prostaglandins. Prostaglandins are produced by the body in response to injury and certain diseases and conditions, and cause pain, swelling and inflammation. Mefenamic acid blocks the production of these prostaglandins and is therefore effective at reducing inflammation and pain.

Mefenamic acid may also work by preventing the action of prostaglandins after they have already been formed.

Mefenamic acid is used to relieve pain and inflammation in a wide range of musculoskeletal conditions, including rheumatoid arthritis, muscular pain and traumatic pain such as sprains, fractures and dislocations. It can also be used to relieve other types of pain, such as toothache, headaches and pain following surgery or childbirth.

Mefenamic acid is also useful for heavy and painful menstrual periods, in addition to its general painkilling properties. This is because this type of pain is caused by the production of prostaglandins.

Mefenamic acid also reduces fever by reducing the production of prostaglandins. Fever is associated with an increase in prostaglandins in the brain, and these prostaglandins cause the body temperature to increase. By reducing prostaglandins in the brain, mefenamic acid lowers body temperature and hence reduces fever. Low doses of mefenamic acid can be used to bring down fevers in children.

What is it used for?

- Rheumatoid arthritis
- Juvenile arthritis (Still's disease)
- Osteoarthritis
- Muscular pain
- Pain and inflammation due to accidents, such as sprains, strains, dislocations, fractures
- Toothache
- Headache
- Painful periods (dysmenorrhoea)
- Abnormally heavy periods
- Pain following childbirth
- Pain following surgery
- Fever in children

Warning!

- This medicine should be taken with or after food to help reduce irritation to the stomach.
- NSAIDs can occasionally cause serious side effects on the gut, such as ulceration, bleeding or perforation of the stomach or intestinal lining. This type of side effect is more likely to occur in elderly people and in people taking high doses of the medicine. The risk can also be increased by taking certain other medicines (see below). It is important that these people, as well as people with a history of disorders affecting the stomach or intestines, are closely monitored by a doctor while taking this medicine. If your doctor thinks you are at high risk of side effects on the gut you may be prescribed an additional medicine to help protect your gut. All people taking this medicine should stop treatment and consult their doctor immediately if they experience any sign of bleeding from the stomach or intestine during treatment, for example vomiting blood and/or passing black/tarry/bloodstained stools.
- If you get diarrhoea while taking this medicine you should stop taking it and consult your doctor. Your doctor may decide that you should not take this medicine again.
- This medicine may mask the signs and symptoms of infection, such as fever and inflammation. This may make you think mistakenly that an infection is getting better when it isn't, or that an infection is less serious than it is. For this reason you should tell your doctor if you get an infection while you are taking this medicine.
- If you have heart failure, liver disease or kidney disease, you are taking diuretic medicines, or you are recovering from major surgery, your kidney function should be assessed before starting and regularly throughout treatment with this medicine.
- During long-term treatment with this medicine you should have regular check-ups with your doctor so that you can be monitored for possible side effects of the medicine. This might include routine blood tests to monitor your kidney function, liver function and levels of blood components, particularly if you are elderly.
- Very rarely, NSAIDS may cause serious blistering or peeling skin reactions (eg Stevens-Johnson syndrome, toxic epidermal necrolysis, exfoliative dermatitis). For this reason, you should stop taking this medicine and consult your doctor if you get a skin rash or sores inside your mouth while taking this medicine. This side effect is very rare, but if it occurs, is most likely to happen in the first month of treatment.
- Children under 12 years of age should be prescribed mefenamic acid liquid, rather than tablets or capsules, as this allows a more accurate dose to be given.

Use with caution in

- Elderly people
- History of disorders affecting the stomach or intestines
- Heart failure
- High blood pressure
- Dehydration
- Epilepsy
- History of allergies
- History of asthma
- People with blood clotting disorders or taking anticoagulants
- Diseases affecting connective tissue, eg systemic lupus erythematosus
- Hereditary blood disorders called porphyrias

Not to be used in

- People in whom aspirin or other NSAIDs, eg ibuprofen, cause allergic reactions such as asthma attacks, itchy rash (urticaria), nasal inflammation (rhinitis) or swelling of the lips, tongue and throat (angioedema)
- Active peptic ulcer or bleeding from the gut
- People who have had recurrent peptic ulcers or bleeding from the gut (two or more episodes)
- People who have experienced bleeding or perforation of the gut as a result of previous treatment with an NSAID
- Inflammatory bowel disease such as ulcerative colitis or Crohn's disease
- Decreased kidney function
- Decreased liver function
- Severe heart failure

This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy. If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.

Pregnancy and Breastfeeding

Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.

- This medicine is not recommended for use in pregnancy unless considered essential by your doctor. This is particularly important in the first and third trimesters. If taken in the third trimester it may delay labour, increase the length of labour and cause complications in the newborn baby. Some evidence suggests that NSAIDs should also be avoided by women attempting to conceive, as they may temporarily reduce female fertility during treatment and may also increase the risk of miscarriage or malformations. Seek medical advice from your doctor.
- This medicine may pass into breast milk in small amounts. The manufacturer states that it should not be used by breastfeeding mothers. Seek medical advice from your doctor.

Label warnings

- Take this medication with or after food.

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