Please check your internet connection and try again.
# Mefenamic acid (Meftal-P)
## Overview
Mefenamic acid is a nonsteroidal anti-inflammatory drug (NSAID) from the fenamate class. It exhibits analgesic, anti-inflammatory, and antipyretic properties through the inhibition of cyclooxygenase (COX) enzymes, thereby reducing prostaglandin synthesis.
## Primary Indications
* Short-term management of mild to moderate pain.
* Primary dysmenorrhea.
## Adult Dosing
* **Pain:** 500 mg every 6 hours as needed.
* **Dysmenorrhea:** 500 mg every 6 hours as needed, starting with the onset of pain and continuing for up to 3 days.
## Pediatric Dosing
* **Pain and Fever:** Generally not recommended for children under 14 years of age. Limited data available for pediatric use. If used, consult specific pediatric guidelines. A common off-label approach for children aged 6 months to 14 years is 6.5 mg/kg every 6 hours, not to exceed 500 mg per dose or 4 doses in 24 hours.
## Dose Adjustments
* **Renal Impairment:** Use with caution. Data is limited, but NSAIDs can exacerbate renal impairment.
* **Hepatic Impairment:** Use with caution. Data is limited.
## Contraindications
* Known hypersensitivity to mefenamic acid, aspirin, other NSAIDs, or any component of the formulation.
* History of gastrointestinal (GI) bleeding or perforation related to previous NSAID therapy.
* Active or history of recurrent peptic ulceration or hemorrhage.
* Severe heart failure.
* Third trimester of pregnancy.
* Children younger than 6 months of age (for fever).
## Adverse Effects
* **Common:** Diarrhea, nausea, vomiting, abdominal pain, dyspepsia, headache, dizziness, rash.
* **Serious:** Gastrointestinal bleeding, ulceration, perforation; renal toxicity (including interstitial nephritis, papillary necrosis); hepatotoxicity; cardiovascular thrombotic events (MI, stroke); hypersensitivity reactions (including anaphylaxis, Stevens-Johnson syndrome); exacerbation of asthma.
## Key Drug Interactions
* **Anticoagulants (e.g., warfarin):** Increased risk of bleeding.
* **Corticosteroids:** Increased risk of GI ulceration and bleeding.
* **Selective Serotonin Reuptake Inhibitors (SSRIs) / Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs):** Increased risk of GI bleeding.
* **Diuretics, ACE inhibitors, Angiotensin II Receptor Blockers (ARBs):** Reduced antihypertensive efficacy and increased risk of renal impairment.
* **Lithium:** Increased lithium levels and risk of toxicity.
* **Methotrexate:** Increased methotrexate levels and toxicity.
## Monitoring
* Signs and symptoms of GI bleeding or ulceration.
* Renal function (especially in patients with pre-existing renal disease or risk factors).
* Liver function tests if used long-term or in patients with hepatic impairment.
* Blood pressure, especially if used concurrently with antihypertensives.
## Clinical Pearls
* Mefenamic acid is typically for short-term use.
* The maximum daily dose in adults should not exceed 4000 mg, and treatment should not exceed 7 consecutive days.
* Due to its potential for GI side effects, it should be taken with food or milk.
* Discontinue use at the first sign of rash, skin reaction, or hypersensitivity.
***
**Disclaimer:** This information is intended for healthcare professionals. Always consult the most current prescribing information and guidelines, as well as patient-specific factors, before making clinical decisions.
