Please check your internet connection and try again.
# Mefenamic Acid
## Overview
Mefenamic acid is a nonsteroidal anti-inflammatory drug (NSAID) that inhibits prostaglandin synthesis. It is indicated for short-term use (typically not exceeding 7 days) for mild to moderate pain.
## Primary Indications
* Pain associated with dysmenorrhea
* Mild to moderate pain (e.g., headache, dental pain, musculoskeletal pain)
## Adult Dosing
* **Initial dose:** 500 mg orally.
* **Subsequent doses:** 250 mg orally every 6 hours as needed.
* **Maximum dose:** Not to exceed 500 mg every 6 hours (3000 mg per day) or 7 days of continuous use.
## Pediatric Dosing
Mefenamic acid is **not recommended** for use in children under 14 years of age due to limited data or risks.
## Dose Adjustments
No specific dose adjustments are typically required for hepatic or renal impairment, however, caution is advised due to potential for renal adverse effects with NSAIDs. Use the lowest effective dose for the shortest duration necessary.
## Contraindications
* Known hypersensitivity to mefenamic acid, aspirin, other NSAIDs, or any component of the formulation.
* History of asthma, urticaria, or allergic-type reactions after taking aspirin or other NSAIDs.
* Peri-operative pain in the setting of coronary artery bypass graft (CABG) surgery.
* Active gastrointestinal (GI) bleeding, ulceration, or perforation.
* History of GI bleeding or ulceration with prior NSAID use.
* Severe heart failure, renal failure, or hepatic failure.
## Adverse Effects
* **Common:** Nausea, vomiting, diarrhea, abdominal pain, dyspepsia, constipation, dizziness, drowsiness.
* **Serious:** Cardiovascular thrombotic events (MI, stroke), GI bleeding, ulceration, perforation, renal toxicity, hepatic toxicity, hypersensitivity reactions, Stevens-Johnson syndrome, toxic epidermal necrolysis.
## Key Drug Interactions
* **Anticoagulants (e.g., warfarin):** Increased risk of bleeding. Monitor INR closely.
* **Corticosteroids:** Increased risk of GI ulceration and bleeding.
* **Selective Serotonin Reuptake Inhibitors (SSRIs):** Increased risk of GI bleeding.
* **Other NSAIDs (including aspirin):** Increased risk of GI adverse effects and reduced cardioprotective effects of low-dose aspirin.
* **Diuretics, ACE inhibitors, ARBs:** Increased risk of renal impairment.
* **Lithium, Methotrexate:** Increased serum levels and toxicity.
## Monitoring
* Monitor for signs and symptoms of GI bleeding (e.g., melena, hematemesis).
* Monitor for cardiovascular events.
* Monitor renal function (BUN, creatinine) and electrolytes, especially in patients with pre-existing renal disease or those at risk.
* Monitor liver function tests (LFTs), especially with prolonged use or in patients with hepatic impairment.
* Monitor for signs of hypersensitivity reactions.
## Clinical Pearls
* Mefenamic acid is intended for short-term management of pain.
* Administer with food or milk to minimize GI upset.
* Avoid concomitant use with other NSAIDs.
* Consider risk factors for cardiovascular and GI events before initiating therapy.
***
*Disclaimer: This information is intended for healthcare professionals and does not replace current prescribing information. Always consult the official drug monograph and institutional protocols for the most up-to-date and complete information before making any clinical decisions.*
