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 functions by inhibiting 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.
* **Primary Dysmenorrhea:** 500 mg every 6 hours as needed, initiated at the onset of pain or bleeding.
The maximum daily dose is 1500 mg. Dosing duration should not exceed 7 days for any single treatment course.
## Pediatric Dosing
Mefenamic acid is generally not recommended for children under 14 years of age due to lack of established safety and efficacy data.
## Dose Adjustments
No specific dose adjustments are typically required for renal or hepatic impairment, however caution is advised. For elderly patients, a lower starting dose may be considered.
## Contraindications
* Hypersensitivity to mefenamic acid, aspirin, or other NSAIDs.
* History of asthma, urticaria, or allergic-type reactions after taking aspirin or other NSAIDs.
* Perioperative pain in the setting of coronary artery bypass graft (CABG) surgery.
* Inflammatory bowel disease.
* Severe renal impairment.
* Severe hepatic impairment.
* Severe heart failure.
## Adverse Effects
Common adverse effects include:
* Gastrointestinal: Nausea, vomiting, diarrhea, abdominal pain, dyspepsia, constipation.
* Central Nervous System: Dizziness, headache, drowsiness.
* Dermatologic: Rash, pruritus.
* Hematologic: Anemia.
Serious adverse effects can include gastrointestinal bleeding, perforation, ulceration, cardiovascular thrombotic events, myocardial infarction, stroke, renal failure, and hypersensitivity reactions.
## Key Drug Interactions
* **Anticoagulants (e.g., warfarin):** Increased risk of bleeding.
* **Corticosteroids:** Increased risk of gastrointestinal ulceration and bleeding.
* **Selective Serotonin Reuptake Inhibitors (SSRIs) and Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs):** Increased risk of bleeding.
* **Lithium:** Increased lithium levels and potential toxicity.
* **Methotrexate:** Increased methotrexate toxicity.
* **Diuretics and Antihypertensives:** Reduced antihypertensive effect; increased risk of renal impairment.
## Monitoring
* Signs and symptoms of gastrointestinal bleeding (e.g., melena, hematemesis).
* Renal function (serum creatinine, BUN).
* Liver function tests (LFTs) in patients with pre-existing liver disease.
* Blood pressure.
* Signs of hypersensitivity reactions.
## Clinical Pearls
* Mefenamic acid should be taken with food or milk to minimize gastrointestinal upset.
* Due to its potential for serious adverse effects, it should be used at the lowest effective dose for the shortest duration necessary.
* It is not a substitute for aspirin in the prevention of cardiovascular events.
* Inform patients about the risks of bleeding and cardiovascular events associated with NSAID use.
***
*This information is for educational purposes only and does not substitute for professional medical advice. Always consult with a qualified healthcare provider to determine the appropriateness of any medication for a specific condition and to review the most current prescribing information.*
