Please check your internet connection and try again.
# Mefenamic Acid (Meftal)
## Overview
Mefenamic acid is a nonsteroidal anti-inflammatory drug (NSAID) with analgesic, anti-inflammatory, and antipyretic properties. It acts by inhibiting cyclooxygenase (COX-1 and COX-2) enzymes, reducing prostaglandin synthesis.
## Primary Indications
* Management of mild to moderate pain.
* Primary dysmenorrhea.
* *Note:* Use is generally limited to short-term therapy (≤ 7 days).
## Adult Dosing
* **Initial Dose:** 500 mg orally once.
* **Maintenance:** 250 mg orally every 6 hours as needed.
* **Maximum Duration:** Do not exceed 7 days of treatment.
## Pediatric Dosing
* **Children ≥ 14 years:** Use adult dosing.
* **Children < 14 years:** Safety and efficacy are not well-established; use is generally not recommended unless specified by institutional protocol or regional clinical guidelines.
## Dose Adjustments
* **Renal Impairment:** Contraindicated in severe renal impairment. Use with caution in mild-to-moderate impairment; monitor closely.
* **Hepatic Impairment:** Use with extreme caution. Dose reduction may be required. Contraindicated in severe hepatic disease.
## Contraindications
* Known hypersensitivity to mefenamic acid or aspirin/other NSAIDs.
* History of asthma, urticaria, or allergic-type reactions after taking aspirin or other NSAIDs.
* Active peptic ulcer disease or gastrointestinal bleeding.
* History of inflammatory bowel disease.
* Severe renal or hepatic failure.
* Perioperative pain in the setting of coronary artery bypass graft (CABG) surgery.
## Adverse Effects
* **Gastrointestinal:** Abdominal pain, dyspepsia, diarrhea (frequent), nausea, GI ulceration, or bleeding.
* **Renal:** Fluid retention, edema, risk of acute renal failure.
* **Cardiovascular:** Increased risk of thrombotic events, myocardial infarction, and stroke (common to all non-aspirin NSAIDs).
* **Hematologic:** Anemia, leukopenia, thrombocytopenia (rare but serious).
## Key Drug Interactions
* **Anticoagulants (e.g., Warfarin):** Increases risk of bleeding.
* **Other NSAIDs/Aspirin:** Increases risk of GI toxicity and bleeding.
* **Antihypertensives (ACE inhibitors, ARBs, Diuretics):** May diminish the antihypertensive effect and increase the risk of nephrotoxicity.
* **Lithium/Methotrexate:** NSAIDs may increase serum levels and toxicity risk.
## Monitoring
* **Baseline/Intermittent:** Renal function (BUN/Creatinine), CBC (for long-term use), and blood pressure.
* **Patient assessment:** Monitor for signs of gastrointestinal bleeding (melena, hematemesis) or unexplained weight gain/edema.
## Clinical Pearls
* **Administration:** Take with food or milk to minimize gastrointestinal upset.
* **Diarrhea:** Mefenamic acid is uniquely associated with the potential for severe diarrhea; discontinue the drug if this occurs.
* **Cardiovascular Warning:** Avoid in patients with established cardiovascular disease or those at high risk unless the benefits outweigh the risks.
* **"Meftal-P":** Note that brand formulations may contain additional ingredients (e.g., paracetamol/dicyclomine). Always verify the specific brand composition to avoid double-dosing or redundant therapeutic agents.
***
**Educational Disclaimer:** This information is for educational purposes only. Clinical practices vary by region and institution. Always consult the most recent product monograph, local formularies, and peer-reviewed clinical guidelines before prescribing or administering medication.
