Indications

Mefenamic Acid is indicated for-

  • Fever
  • Toothache
  • Headache
  • Migraine
  • Primary dysmenorrhoea
  • Menorrhagia
  • Mild to moderate pain in rheumatoid arthritis and osteoarthritis
  • Traumatic pain
  • Low-back pain
  • Juvenile chronic arthritis in children etc.

Pharmacology

Mefenamic acid contains Mefenamic Acid which is a nonsteroidal agent with demonstrated analgesic, anti-inflammatory and antipyretic activity due to its dual action on prostaglandins. It inhibits the enzymes of prostaglandin synthetase and also antagonizes the actions of prostaglandin at the receptor sites.

Dosage And Administration

Adult:

  • 500 mg dose should be given to adults upto three times (1.5 gm total) per day with meals. The dosage may be reduced to 1 tablet (250 mg) three times daily.
  • In case of menorrhagia: 500 mg three times daily with meals and from the onset of menses and continued according to the judgement of the physician.

Children:

  • 6 months to 1 year: 5 ml three times/day.
  • 2-4 years: 10 ml three times/day.
  • 5-8 years: 10 ml four times /day.
  • 9-12 years: 15 ml four times/day.

Treatment should not be continued for more than 7 days except on the advice of a physician.

Interaction

Aspirin: As other NSAIDs, concomitant administration of Mefenamic Acid and Aspirin is not generally recommended because of the potential of increased adverse effects.

Warfarin: Mefenamic Acid can inhibit platelet aggregation and may prolong the prothrombin time in patients on warfarin therapy.

Contraindications

It is contraindicated in patients with known hypersensitivity to Mefenamic Acid. It should not be used in patients with peptic ulcer, inflammatory bowel diseases, hepatic or renal impairment. It is also contraindicated in patients, whom aspirin and/or other NSAID's have induced symptoms of bronchospasm, skin rashes etc.

Side Effects

The most frequently reported adverse experiences occurring in approximately 1-10% of patients are gastrointestinal: abdominal pain, constipation, diarrhoea, dyspepsia, flatulence, nausea, Gl ulcers, vomiting, dizziness, abnormal renal function, pruritus, rashes.

Pregnancy And Lactation

The safety of Mefenamic acid on reproductive capacity and pregnancy has not been established. Thus, mefenamic acid should be used in women of childbearing potential and during pregnancy only when the potential benefits are expected to outweigh the potential risks. Trace amounts of Mefenamic acid may be present in breast milk and transmitted to the nursing infant. Thus Mefenamic acid should not be taken by the nursing mother because of the effects of this class of drugs on the infant's cardiovascular system.

Precautions And Warnings

It should be administered with caution in allergic diseases especially in asthma. The treatment should be withdrawn in diarrhoea, rashes, cholestatic jaundice, thrombocytopenia, haemolytic anaemia.

Therapeutic Class

Drugs for Osteoarthritis, Drugs used for Rheumatoid Arthritis, Non-steroidal Anti-inflammatory Drugs (NSAIDs).

Storage Conditions

Keep away from light, store in a cool and dry place. Keep out of reach of children.