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 exhibits analgesic, anti-inflammatory, and antipyretic properties.
## Primary Indications
* Management of mild to moderate pain, including menstrual pain (dysmenorrhea).
* Relief of pain and inflammation associated with osteoarthritis and rheumatoid arthritis.
## Adult Dosing
* **Pain (including dysmenorrhea):** 500 mg every 4 to 6 hours as needed. Do not exceed 1500 mg in a 24-hour period.
* **Rheumatoid Arthritis/Osteoarthritis:** 500 mg three times daily. Do not exceed 1500 mg in a 24-hour period.
## Pediatric Dosing
Mefenamic acid is generally not recommended for children under 14 years of age for pain relief. Limited data exists for other indications. Consult specific pediatric guidelines or expert consultation if considering use.
## Dose Adjustments
* **Renal Impairment:** Use with caution. Dose reduction may be necessary in severe impairment.
* **Hepatic Impairment:** Use with caution. Dose reduction may be necessary.
* **Elderly:** Increased risk of adverse effects; consider lower doses.
## Contraindications
* Known hypersensitivity to mefenamic acid 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.
* Active gastrointestinal bleeding or history of recurrent peptic ulceration.
## Adverse Effects
* **Gastrointestinal:** Nausea, vomiting, diarrhea, abdominal pain, dyspepsia, constipation, gastritis, peptic ulceration, GI bleeding.
* **Central Nervous System:** Dizziness, drowsiness, headache.
* **Renal:** Renal impairment, interstitial nephritis, papillary necrosis.
* **Hematologic:** Anemia, leukopenia, thrombocytopenia.
* **Cardiovascular:** Increased risk of myocardial infarction and stroke.
* **Dermatologic:** Rash, pruritus.
* **Other:** Bronchospasm, hypersensitivity reactions, photosensitivity.
## Key Drug Interactions
* **Anticoagulants (e.g., warfarin):** Increased risk of bleeding.
* **Corticosteroids:** Increased risk of GI ulceration and bleeding.
* **ACE inhibitors, ARBs, diuretics:** Reduced antihypertensive effect, increased risk of renal impairment.
* **Lithium:** Increased lithium levels.
* **Methotrexate:** Increased methotrexate toxicity.
* **Other NSAIDs/Aspirin:** Increased risk of GI adverse effects.
## Monitoring
* **Renal function** (serum creatinine, BUN) periodically, especially in elderly patients or those with risk factors.
* **Liver function** (LFTs) periodically.
* **Complete blood count (CBC)** periodically.
* **Signs and symptoms of GI bleeding** (e.g., melena, hematemesis).
* **Blood pressure.**
## Clinical Pearls
* Shortest duration of therapy and lowest effective dose should be used.
* Take with food or milk to minimize GI upset.
* Avoid concurrent use with other NSAIDs.
* Educate patients on potential for serious GI, cardiovascular, and renal adverse effects.
* Use with caution in patients with pre-existing renal or hepatic disease, heart failure, or hypertension.
---
***Disclaimer:** This information is intended for healthcare professionals. Always consult the most current prescribing information and relevant guidelines for complete and up-to-date details before making any clinical decisions.*
