Please check your internet connection and try again.
# Mefenamic Acid
## Overview
Mefenamic acid is a nonsteroidal anti-inflammatory drug (NSAID) belonging to the anthranilic acid derivatives class. It possesses analgesic, anti-inflammatory, and antipyretic properties.
## Primary Indications
* Short-term management of mild to moderate pain.
* Primary dysmenorrhea.
## Adult Dosing
* **Pain:** 500 mg every 6 hours as needed. Maximum daily dose is 1500 mg.
* **Dysmenorrhea:** 500 mg every 4 to 6 hours as needed, not to exceed 1500 mg daily. Treatment should begin at the onset of bleeding and pain and continue for the duration of the symptoms, up to 7 days.
## Pediatric Dosing
Mefenamic acid is generally not recommended for use in children under 14 years of age due to lack of established safety and efficacy.
## Dose Adjustments
No specific dose adjustments are typically required for renal or hepatic impairment, but caution is advised. NSAIDs can worsen renal function, especially in patients with pre-existing renal disease. Monitor closely.
## Contraindications
* Hypersensitivity to mefenamic acid or other NSAIDs.
* History of bronchospasm, 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 bleeding or history of recurrent gastrointestinal perforation or ulcers.
## Adverse Effects
Common adverse effects include diarrhea, nausea, vomiting, abdominal pain, constipation, and headache. Serious adverse effects include gastrointestinal bleeding and ulceration, cardiovascular thrombotic events (myocardial infarction, stroke), renal toxicity, hepatic toxicity, and hypersensitivity reactions.
## Key Drug Interactions
* **Anticoagulants (e.g., warfarin):** Increased risk of bleeding.
* **Aspirin:** Mefenamic acid may interfere with the antiplatelet effect of low-dose aspirin.
* **Corticosteroids:** Increased risk of gastrointestinal ulceration and bleeding.
* **Diuretics and antihypertensives:** May decrease efficacy and increase risk of renal toxicity.
* **Lithium:** Increased serum lithium levels.
* **Methotrexate:** Increased risk of methotrexate toxicity.
## Monitoring
* Signs and symptoms of gastrointestinal bleeding (e.g., melena, hematemesis).
* Renal function (serum creatinine, BUN), especially in patients with risk factors for renal impairment.
* Liver function tests, especially with prolonged use or in patients with pre-existing liver disease.
* Blood pressure, as NSAIDs can cause fluid retention and hypertension.
## Clinical Pearls
* Mefenamic acid is generally intended for short-term use only.
* Administer with food or milk to minimize gastrointestinal upset.
* Use the lowest effective dose for the shortest duration necessary to reduce the risk of adverse events.
* Be aware of the increased risk of cardiovascular events and gastrointestinal bleeding associated with NSAID use.
***
**Disclaimer:** This information is intended for healthcare professionals. It is essential to consult the most current prescribing information and institutional guidelines before administering any medication. Dosing and recommendations may vary based on individual patient factors and local protocols.
