Please check your internet connection and try again.
# Mefenamic Acid
## Overview
Mefenamic acid is a nonsteroidal anti-inflammatory drug (NSAID) belonging to the fenamate class. It has analgesic, anti-inflammatory, and antipyretic properties.
## Primary Indications
* Short-term management of mild to moderate pain.
* Management of primary dysmenorrhea.
## Adult Dosing
* **Pain:** 500 mg every 4 to 6 hours as needed. Do not exceed 4000 mg per day.
* **Dysmenorrhea:** 500 mg every 4 to 6 hours as needed, typically started at the onset of bleeding and associated pain. Do not exceed 4000 mg per day.
* Treatment should generally be limited to 7 days.
## Pediatric Dosing
Mefenamic acid is **not generally recommended for children under 14 years of age** due to limited safety and efficacy data. Specific pediatric dosing is not established.
## Dose Adjustments
* **Renal Impairment:** Use with caution. Dose reduction may be necessary in severe impairment, but specific guidelines are lacking.
* **Hepatic Impairment:** Use with caution. Dose reduction may be necessary in severe impairment, but specific guidelines are lacking.
* **Elderly:** Increased risk of adverse events, particularly gastrointestinal bleeding and renal effects. Consider lower doses and monitor closely.
## Contraindications
* Hypersensitivity to mefenamic acid, aspirin, or other NSAIDs.
* History of bronchospasm, asthma, allergic rhinitis, or urticaria precipitated by aspirin or other NSAIDs.
* Perioperative pain in the setting of coronary artery bypass graft (CABG) surgery.
* Inflammatory bowel disease (use with caution).
* Third trimester of pregnancy.
## Adverse Effects
**Serious:** Cardiovascular thrombotic events (myocardial infarction, stroke), serious gastrointestinal bleeding, ulceration, perforation, renal failure, hepatic failure, hypersensitivity reactions, severe skin reactions (e.g., Stevens-Johnson syndrome, toxic epidermal necrolysis).
**Common:** Nausea, vomiting, diarrhea, abdominal pain, dyspepsia, constipation, dizziness, headache.
## Key Drug Interactions
* **Anticoagulants (e.g., warfarin):** Increased risk of bleeding.
* **Corticosteroids:** Increased risk of GI ulceration and bleeding.
* **SSRIs/SNRIs:** Increased risk of GI bleeding.
* **ACE inhibitors, ARBs, beta-blockers:** May reduce antihypertensive effect and increase risk of renal impairment.
* **Diuretics:** May reduce diuretic effect and increase risk of renal impairment.
* **Lithium, Methotrexate:** Increased serum levels and toxicity.
* **Other NSAIDs/Salicylates:** Increased risk of adverse effects, particularly GI.
## Monitoring
* Signs and symptoms of gastrointestinal bleeding (e.g., hematemesis, melena, abdominal pain).
* Renal function (serum creatinine, BUN).
* Liver function (AST, ALT).
* Blood pressure.
* Signs of fluid retention or edema.
## Clinical Pearls
* Administer with food or milk to minimize gastrointestinal upset.
* Due to potential for serious gastrointestinal events, use the lowest effective dose for the shortest duration necessary.
* Mefenamic acid is typically for short-term use. For chronic pain or inflammation, other NSAIDs or non-pharmacologic therapies may be more appropriate.
* Not typically a first-line agent for pain management due to its adverse effect profile and duration of action compared to other NSAIDs.
***
*Disclaimer: This information is intended for healthcare professionals. Always consult the official prescribing information and local guidelines for complete and up-to-date details before prescribing or administering any medication.*
