Mefenamic Acid

Mefenamic Acid – Full Introduction

Mefenamic acid is a non-steroidal anti-inflammatory drug (NSAID) primarily used for the treatment of mild to moderate pain, especially menstrual pain (dysmenorrhea). It also has analgesic, antipyretic, and anti-inflammatory properties and is commonly prescribed for short-term use.

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Drug Class

• Non-steroidal anti-inflammatory drug (NSAID)

• Fenamate derivative

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Mechanism of Action

Mefenamic acid works by reversibly inhibiting cyclo-oxygenase enzymes (COX-1 and COX-2), leading to reduced synthesis of prostaglandins, which are responsible for:

• Pain

• Inflammation

• Fever

By lowering prostaglandin levels, it effectively relieves pain, particularly uterine contractions associated with menstruation.

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Therapeutic Uses

• Primary dysmenorrhea (menstrual pain)

• Mild to moderate pain (toothache, headache, musculoskeletal pain)

• Post-operative pain

• Fever (short-term use)

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Benefits

• Highly effective for menstrual cramps

• Rapid onset of analgesic action

• Useful in short-term painful conditions

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Common Side Effects

• Gastrointestinal upset (nausea, vomiting, diarrhea, abdominal pain)

• Heartburn

• Dizziness

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Serious but Rare Side Effects

• Peptic ulceration and GI bleeding

• Renal impairment

• Hypersensitivity reactions

• Hemolytic anemia (very rare, especially in patients with G6PD deficiency)

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Contraindications & Precautions

• History of peptic ulcer disease or GI bleeding

• Severe renal impairment

• NSAID-induced asthma

• Inflammatory bowel disease

• Use cautiously in elderly patients

• Avoid prolonged use

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Dosage & Administration

• Adults: 500 mg initially, followed by 250 mg every 6 hours as needed

• Usually prescribed for short duration (2–7 days)

• Take with food to minimize gastric irritation

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Conclusion

Mefenamic acid is an effective NSAID for short-term pain relief, particularly in dysmenorrhea. Due to its gastrointestinal and renal side effects, it should be used at the lowest effective dose for the shortest possible duration.