Generic
Mefenamic Acid
23 brands available in the market
At a glance
Mefenamic Acid is an NSAID used for moderate to severe pain such as menstrual pain, headache, muscle pain, joint pain, and dental pain.
Description
Mefenamic acid is an anthranilic acid derivative that inhibits COX-1 and COX-2 enzymes, reducing prostaglandin synthesis. It has analgesic and antipyretic properties with minor anti-inflammatory activity.
Indications
- 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
Therapeutic class
Drugs for Osteoarthritis, Drugs used for Rheumatoid Arthritis
Pharmacological class
Non-steroidal Anti-inflammatory Drug (NSAID)
Pharmacology
Mefenamic acid inhibits COX-1 and COX-2 enzymes to reduce prostaglandin synthesis and antagonizes prostaglandin actions at receptor sites.
Mechanism of action
Reduces pain and inflammation by inhibiting prostaglandin synthesis.
Dosage
Adult Dose (Oral):
- 250-500 mg up to 3 times daily, for 3-7 days; max 1.5 g/day
- Menorrhagia: 500 mg 3 times daily from the onset of menses
Children (>6 months): 25 mg/kg/day in divided doses, up to 7 days
Administration
- Dissolve tablet in a glass of water before taking
- Take with food
- Take at the same time each day
Missed dose
If you miss a dose, take it as soon as you remember; skip if it's almost time for next dose; do not double the dose.
Side effects
Common Side Effects (1-10%):
- Abdominal pain, constipation, diarrhea, dyspepsia, flatulence
- Nausea, vomiting
- Dizziness
- Pruritus, rash
- Loss of appetite
Precautions & warnings
- Caution when driving or doing activities requiring concentration (may cause drowsiness and dizziness)
- Caution in patients with asthma
- Caution in peptic ulcer, inflammatory bowel disease, liver/kidney problems
- Discontinue if diarrhea, rash, cholestatic jaundice, thrombocytopenia occur
Contraindications
- Hypersensitivity to mefenamic acid, aspirin, or other NSAIDs
- Inflammatory bowel disease, active ulceration
- Renal failure
- History of asthma, urticaria, allergic-type reactions
- Coronary artery bypass graft surgery
- Third trimester of pregnancy, lactation
Drug interactions
- CYP2C9 inhibitors may alter safety and efficacy
- May enhance methotrexate toxicity
- Reduced BP response to ACE inhibitors or angiotensin II receptor antagonists
- Increased risk of serious GI events with aspirin
- May reduce natriuretic effects of furosemide or thiazide diuretics
- Reduced lithium clearance and elevated plasma lithium levels
Food interactions
Alcohol consumption with Mefenamic Acid is unsafe.
Use in pregnancy
Use in Pregnancy: Mefenamic Acid may be unsafe during pregnancy; animal studies have shown harmful effects on the fetus. Consult your doctor.
Pregnancy Category: C — always consult a doctor before taking during pregnancy.
Use in lactation
Use in Lactation: Mefenamic Acid is safe during breastfeeding; does not pass into breastmilk in significant amounts.
Pediatric use
Dose established for children over 6 months.
Geriatric use
Caution needed in elderly.
Renal / hepatic impairment
Renal Impairment: Caution in kidney disease; dose adjustment may be needed; not recommended in severe kidney disease.
Hepatic Impairment: Caution in liver disease; dose adjustment may be needed.
Overdose effects
Overdose may cause GI and CNS symptoms; symptomatic treatment.
Storage conditions
Store in a cool and dry place, away from light; keep out of reach of children.
Chemical structure
Mefenamic Acid