Please check your internet connection and try again.
# Mefenamic Acid
## Overview
Mefenamic acid is a nonsteroidal anti-inflammatory drug (NSAID) with analgesic and anti-inflammatory properties. It is thought to work by inhibiting cyclooxygenase (COX) enzymes, thereby reducing prostaglandin synthesis.
## Primary Indications
* Short-term relief of mild to moderate pain.
* Menstrual pain (primary dysmenorrhea).
## Adult Dosing
* **Pain:** 500 mg every 6 hours as needed. Maximum of 1500 mg per day.
* **Primary Dysmenorrhea:** 500 mg every 6 hours, starting at the onset of pain or bleeding, whichever occurs first, and continuing for the duration of the pain. Maximum of 1500 mg per day.
## Pediatric Dosing
Mefenamic acid is generally not recommended for use in children under 14 years of age due to a lack of established safety and efficacy data.
## Dose Adjustments
* **Renal Impairment:** Use with caution. Doses may need to be reduced in severe renal impairment.
* **Hepatic Impairment:** Use with caution. Doses may need to be reduced in severe hepatic impairment.
## 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.
## Adverse Effects
* **Common:** Diarrhea, nausea, vomiting, abdominal pain, constipation, dizziness, rash.
* **Serious:** Gastrointestinal bleeding, ulceration, perforation; cardiovascular thrombotic events (MI, stroke); renal failure; hepatic failure; hypersensitivity reactions.
## Key Drug Interactions
* **Anticoagulants (e.g., warfarin):** Increased risk of bleeding.
* **Corticosteroids:** Increased risk of GI ulceration and bleeding.
* **Other NSAIDs or Salicylates:** Increased risk of adverse effects, particularly GI toxicity.
* **Diuretics, ACE inhibitors, ARBs:** Reduced antihypertensive effect and increased risk of renal impairment.
* **Lithium:** Increased serum lithium levels.
* **Methotrexate:** Increased methotrexate toxicity.
## Monitoring
* Monitor for signs and symptoms of GI bleeding (e.g., melena, hematemesis).
* Monitor renal and hepatic function, especially in patients with pre-existing impairment or those on long-term therapy.
* Monitor for signs of cardiovascular events.
## Clinical Pearls
* Shorten duration of therapy to the lowest effective dose to minimize risk of adverse effects.
* Administer with food or milk to reduce gastrointestinal upset.
* Avoid use in patients with a history of peptic ulcer disease or GI bleeding.
* Discontinue if significant diarrhea occurs, as this can be a sign of colitis.
---
*This information is intended for healthcare professionals and is not a substitute for professional medical advice. Always consult the most current prescribing information and relevant clinical guidelines before making any treatment decisions.*
