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 derivative class. It possesses analgesic, anti-inflammatory, and antipyretic properties.
## Primary Indications
* Short-term management of mild to moderate pain, including menstrual pain (dysmenorrhea), dental pain, and musculoskeletal pain.
* Management of rheumatoid arthritis and osteoarthritis (though less commonly used than other NSAIDs).
## Adult Dosing
* **Pain:** 500 mg every 6-8 hours as needed.
* **Dysmenorrhea:** 500 mg initially, followed by 250 mg every 6-8 hours as needed.
* **Rheumatoid Arthritis/Osteoarthritis:** 500 mg three times daily.
* **Maximum Daily Dose:** 1500 mg.
## Pediatric Dosing
* Mefenamic acid is generally **not recommended** for children under 14 years of age for pain management due to a lack of established safety and efficacy data.
* For specific indications and age groups, refer to specialized pediatric formularies.
## Dose Adjustments
* **Renal Impairment:** Use with caution. Dose reduction may be necessary in severe impairment. Monitor renal function closely.
* **Hepatic Impairment:** Use with caution. Monitor hepatic function.
## Contraindications
* Known hypersensitivity to mefenamic acid, aspirin, or other NSAIDs.
* Perioperative pain in the setting of coronary artery bypass graft (CABG) surgery.
* History of gastrointestinal bleeding or perforation related to previous NSAID use.
* Active peptic ulceration or history of recurrent peptic ulceration.
* Severe renal or hepatic impairment.
* Severe heart failure.
* Late pregnancy (third trimester).
## Adverse Effects
* **Gastrointestinal:** Dyspepsia, nausea, vomiting, diarrhea, abdominal pain, constipation, ulceration, bleeding, perforation.
* **Renal:** Acute kidney injury, interstitial nephritis, papillary necrosis.
* **Cardiovascular:** Increased risk of thrombotic events (myocardial infarction, stroke), hypertension, edema.
* **Hepatic:** Elevated liver enzymes, hepatitis, jaundice.
* **Hematologic:** Anemia, leukopenia, thrombocytopenia.
* **Dermatologic:** Rash, pruritus, Stevens-Johnson syndrome, toxic epidermal necrolysis.
* **Other:** Dizziness, headache, drowsiness, tinnitus, bronchospasm (especially in aspirin-sensitive asthma).
## Key Drug Interactions
* **Anticoagulants (e.g., warfarin):** Increased risk of bleeding.
* **Corticosteroids:** Increased risk of GI ulceration and bleeding.
* **Selective Serotonin Reuptake Inhibitors (SSRIs):** Increased risk of GI bleeding.
* **Diuretics and Antihypertensives:** Reduced efficacy, increased risk of nephrotoxicity.
* **Lithium:** Increased lithium levels and toxicity.
* **Methotrexate:** Increased methotrexate toxicity.
## Monitoring
* **Renal function:** Serum creatinine, BUN.
* **Hepatic function:** Liver enzymes (AST, ALT).
* **Gastrointestinal symptoms:** Signs of bleeding or ulceration.
* **Blood pressure:** Especially in patients with hypertension.
* **Signs of fluid retention:** Edema, weight gain.
## Clinical Pearls
* Administer with food or milk to minimize gastrointestinal upset.
* Limit duration of use to the shortest effective period due to risks of GI, renal, and cardiovascular toxicity.
* Avoid concurrent use with other NSAIDs to reduce adverse event risk.
* Discontinue immediately if signs of hypersensitivity, GI bleeding, or serious adverse events occur.
* Consider alternative analgesics for patients with significant cardiovascular disease, renal impairment, or a history of peptic ulcer disease.
***
*This information is intended for healthcare professionals. It is essential to consult the most current prescribing information and relevant literature for complete details and to verify the accuracy of this information before making clinical decisions.*
