logo image

Mefenamic Acid information from DrugsUpdate  

See Available Brands of Mefenamic Acid in India

P - Contraindicated in pregnancy
L - Contraindicated in lactation
LI - Lab *

Mefenamic acid is a non-steroidal anti-inflammatory drug used to treat pain, including menstrual pain. It is typically prescribed for oral administration.

Mefenamic acid decreases inflammation (swelling) and uterine contractions by a still unknown mechanism. However it is thought to be related to the inhibition of prostaglandin synthesis.

Since hepatic metabolism plays a significant role in mefenamic acid elimination, patients with known liver deficiency may be prescribed lower doses. Kidney deficiency may also cause accumulation of the drug and its metabolites in the excretory system. Therefore patients suffering from renal conditions should not be prescribed mefenamic acid.


Mefenamic Acid is a non-steroidal anti-inflammatory drug (NSAID) that exhibits anti-inflammatory, analgesic, and antipyretic activities in animal models. The mechanism of action of Mefenamic Acid, like that of other NSAIDs, is not completely understood but may be related to prostaglandin synthetase inhibition.


Mefenamic acid inhibits the enzymes cyclooxygenase (COX)-1 and COX-2 and reduces the formation of prostaglandins and leukotrienes. It also acts as an antagonist at prostaglandin receptor sites. It has analgesic and antipyretic properties with minor anti-inflammatory activity.


Absorbed from the GIT (oral); peak plasma concentrations after 2-4 hours.

Enters breast milk (small amounts). >90% bound to plasma albumin. Apparent volume of distribution 1.06 l/kg.


Hepatic via enzyme CYP2C9.


Urine (52%) as unchanged drug and metabolites; faeces (20%). Elimination half life 2-4 hours.
CIMS Class

Mefenamic Acid Indications / Mefenamic Acid Uses

Information Not Available

Mefenamic Acid Adverse Reactions / Mefenamic Acid Side Effects

Abdominal pain, dyspepsia, constipation, diarrhoea, nausea, GI ulcers; oedema; bronchospasm; headache, drowsiness, insomnia, visual disturbances; CHF, hypertension, tachycardia, syncope; urticaria, rash; thrombocytopenia, aplastic anaemia, agranulocytosis; tinnitus; elevated liver enzymes; abnormal renal function.

Potentially Fatal: Autoimmune haemolytic anaemia; convulsions (overdosage).


Mefenamic Acid cannot be expected to substitute for corticosteroids or to treat corticosteroid insufficiency.  Abrupt discontinuation of corticosteroids may lead to disease exacerbation.  Patients on prolonged corticosteroid therapy should have their therapy tapered slowly if a decision is made to discontinue corticosteroids. The pharmacological activity of Mefenamic Acid in reducing fever and inflammation may diminish the utility of these diagnostic signs in detecting complications of presumed noninfectious, painful conditions.

Special Precautions

Renal and hepatic impairment, asthma. Monitor blood counts and liver function during long-term therapy. Drowsiness may affect ability to perform skilled tasks. Elderly.

Other Drug Interactions

Enhances activity of oral anticoagulants but rarely significant. Increases risk of GI irritation with alcohol. Increased ciclosporin, lithium toxicity and convulsions reported with ciprofloxacin. Absorption increased by magnesium hydroxide antacids. ACE inhibitor effects may be antagonised.

Other Interactions

Information Not Available


Mild to moderate pain, Rheumatoid arthritis, Dental pain, Postoperative pain, Dysmenorrhoea, Osteoarthritis, Menorrhagia
Adult: 250-500 mg tid.
Child: >6 months: 25 mg/kg daily in divided doses for up to 7 days.


Should be taken with food.

List of Contraindications

Mefenamic Acid and Pregnancy

Contraindicated in pregnancy

Category C: Either studies in animals have revealed adverse effects on the foetus (teratogenic or embryocidal or other) and there are no controlled studies in women or studies in women and animals are not available. Drugs should be given only if the potential benefit justifies the potential risk to the foetus.

In 3rd trimester or near delivery.
Category D: There is positive evidence of human foetal risk, but the benefits from use in pregnant women may be acceptable despite the risk (e.g., if the drug is needed in a life-threatening situation or for a serious disease for which safer drugs cannot be used or are ineffective).

Mefenamic Acid and Lactation

Contraindicated in lactation

Mefenamic Acid and Children

Not recommended for children younger than 14 years of age

Mefenamic Acid and Geriatic

Increased risk of adverse reactions

Mefenamic Acid and Other Contraindications

Inflammatory bowel disease; peptic ulcer; neonates; pregnancy (3rd trimester), lactation. Coronary artery bypass graft surgery, severe renal impairment, severe heart failure.


Information Not Available

Lab interference

Information Not Available

© 2011-2020 DrugsUpdate.com from UPilot INC. Disclaimer | Site Map

  • Companies that own platforms will own the market
  • Trusted and recognized by all Doctors
  • Access to Millions of Visitors instantly.
  • Companies that own platforms will own the market
  • Trusted and recognized by all Doctors
  • Access to Millions of Visitors instantly.