Please check your internet connection and try again.
# Mefenamic Acid (Meftal-P)
## Overview
Mefenamic acid is a nonsteroidal anti-inflammatory drug (NSAID) of the fenamate class. It possesses analgesic, anti-inflammatory, and antipyretic properties, mediated primarily by the reversible inhibition of cyclooxygenase (COX-1 and COX-2) enzymes, reducing prostaglandin synthesis.
## Primary Indications
* Primary dysmenorrhea (short-term use, rarely exceeding 2–3 days).
* Mild to moderate pain.
* Pyrexia (fever) in pediatric populations (Meftal-P specifically refers to pediatric suspension).
## Adult Dosing
* **Pain/Dysmenorrhea:** 500 mg initially, followed by 250 mg every 6 hours as needed.
* **Maximum Duration:** Should not exceed 7 days of continuous therapy due to gastrointestinal and renal toxicity risks.
## Pediatric Dosing
* **Fever/Pain:** 2–6 mg/kg/dose administered every 6–8 hours as required.
* **Max Daily Dose:** Not to exceed 20 mg/kg/day.
* *Note:* Use is generally restricted to children older than 6 months. Precise dosing must follow local institutional protocols as formulations and concentrations (e.g., 50mg/5ml) vary by region.
## Dose Adjustments
* **Renal Impairment:** Contraindicated in severe renal impairment. Use with extreme caution in mild-to-moderate impairment; monitor creatinine clearance.
* **Hepatic Impairment:** Use with caution; monitor for signs of liver toxicity. Dose reduction may be required.
## Contraindications
* Known hypersensitivity to mefenamic acid or aspirin/other NSAIDs.
* Active peptic ulceration or inflammatory bowel disease (IBD).
* Severe heart failure.
* History of GI bleeding or perforation related to previous NSAID therapy.
* Pre-operative pain management in the setting of coronary artery bypass graft (CABG) surgery.
## Adverse Effects
* **Gastrointestinal:** Diarrhea (common and specific to mefenamic acid), nausea, abdominal pain, GI ulceration/bleeding.
* **Renal:** Fluid retention, edema, acute renal insufficiency.
* **Hematologic:** Anemia, leukopenia, thrombocytopenia (rare but serious).
* **Dermatologic:** Skin rashes, pruritus.
* **Other:** Dizziness, headache.
## Key Drug Interactions
* **Anticoagulants (e.g., Warfarin):** Increased risk of bleeding; monitor INR closely.
* **Antiplatelets (e.g., Clopidogrel):** Increased risk of GI toxicity and hemorrhage.
* **ACE Inhibitors/ARBs/Diuretics:** Increased risk of renal impairment; may diminish the antihypertensive effect.
* **Lithium/Methotrexate:** Decreased clearance, potentially leading to toxic serum levels.
* **Other NSAIDs:** Concurrent use increases the risk of GI ulceration and adverse events.
## Monitoring
* **Baseline/Intermittent:** CBC, renal function (serum creatinine/BUN), and liver function tests (LFTs) if used for more than a few days.
* **Clinical:** Monitor for signs of occult GI bleeding (stools) and fluid retention/worsening edema.
## Clinical Pearls
* **Diarrhea Link:** Mefenamic acid is uniquely associated with the development of severe diarrhea. If diarrhea occurs, the medication should be discontinued immediately.
* **Food:** Administer with or immediately after food to minimize gastrointestinal irritation.
* **Short-Term Limit:** Due to the risk of hemolytic anemia with prolonged use, it is generally intended for short-term management (not exceeding 1 week).
***
**Disclaimer:** This information is for educational purposes and does not replace professional clinical judgment. Always verify exact dosing against the most current local prescribing information (package insert) and pediatric weight-based protocols before administering medication.
