Mefanic%25252525252525252525252525252525252525252525252525252525252525252525252520acid

# Mefenamic Acid ## Overview Mefenamic acid is a nonsteroidal anti-inflammatory drug (NSAID) that inhibits cyclooxygenase (COX) enzymes, thereby reducing prostaglandin synthesis. It is available in oral dosage forms. ## Primary Indications * Short-term relief of mild to moderate pain. * Management of primary dysmenorrhea. ## Adult Dosing * **Pain:** 500 mg every 4 to 6 hours as needed. Do not exceed 1500 mg per day for more than 7 days. * **Dysmenorrhea:** 500 mg every 4 to 6 hours as needed, starting with the onset of bleeding and associated symptoms. Do not exceed 1500 mg per day for more than 7 days. ## Pediatric Dosing Mefenamic acid is **not recommended** for use in children under 14 years of age due to lack of established safety and efficacy. ## Dose Adjustments * **Renal Impairment:** Use with caution. Dose reduction may be necessary in severe renal impairment, though specific guidelines are lacking. Avoid use if creatinine clearance is less than 10 mL/min. * **Hepatic Impairment:** Use with caution. Dose reduction may be necessary in severe hepatic impairment, though specific guidelines are lacking. ## Contraindications * Known hypersensitivity to mefenamic acid, aspirin, other NSAIDs, or any component of the formulation. * 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 or hepatic impairment. * Third trimester of pregnancy. ## Adverse Effects Common adverse effects include diarrhea, nausea, vomiting, abdominal pain, constipation, dizziness, and rash. Serious adverse effects include gastrointestinal bleeding, ulceration, perforation, cardiovascular thrombotic events, myocardial infarction, stroke, renal failure, hepatic failure, and hypersensitivity reactions. ## Key Drug Interactions * **Anticoagulants (e.g., warfarin):** Increased risk of bleeding. * **Corticosteroids:** Increased risk of gastrointestinal ulceration and bleeding. * **SSRIs and SNRIs:** Increased risk of bleeding. * **Other NSAIDs and Salicylates:** Increased risk of adverse effects. * **Diuretics and Antihypertensives:** Reduced efficacy and increased risk of renal impairment. * **Lithium:** Increased lithium levels and toxicity. * **Methotrexate:** Increased methotrexate levels and toxicity. ## Monitoring * **GI Symptoms:** Monitor for signs and symptoms of bleeding, ulceration, or perforation. * **Renal Function:** Monitor serum creatinine and BUN, especially in patients with pre-existing renal disease or those at risk. * **Hepatic Function:** Monitor liver function tests, especially in patients with pre-existing hepatic disease. * **Blood Pressure:** Monitor blood pressure during NSAID therapy. * **Signs of Thrombotic Events:** Monitor for new onset or worsening of cardiovascular symptoms. ## Clinical Pearls * Limit duration of use to the shortest effective period due to increased risk of adverse effects with prolonged use. * Administer with food or milk to minimize gastrointestinal upset. * Diarrhea is a common and sometimes dose-limiting side effect. * Avoid concomitant use with other NSAIDs. *** **Disclaimer:** This information is intended for healthcare professionals. Always consult the most current prescribing information and institutional protocols for definitive guidance. Dosing and safety information can change.