Mefenamic Acid(me fe nam’ ik)
Apo-Mefenamic (CAN), Mefenamic-250 (CAN), Ponstan (CAN), Ponstel
PREGNANCY CATEGORY C
Drug class
NSAID
Therapeutic Actions
Anti-inflammatory, analgesic, and antipyretic activities related to inhibition of prostaglandin synthesis; exact mechanisms of action are not known.
Indications
Relief of moderate pain when therapy will not exceed 1 wk
Treatment of primary dysmenorrhea
Unlabeled uses: Migraine, PMS
Contraindications and Cautions
Contraindicated with hypersensitivity to mefenamic acid, aspirin or NSAID allergy, and as treatment of perioperative pain with coronary artery bypass grafting.
Use cautiously with asthma, renal or hepatic impairment, peptic ulcer disease, GI bleeding, hypertension, heart failure, pregnancy, lactation.
Available Forms
Capsules—250 mg
Dosages
Adults and patients older than 14 yr
Mild to moderate pain: Initially, 500 mg PO followed by 250 mg every 6 hr as needed. Do not exceed 1 wk of therapy.
Primary dysmenorrhea: Initially, 500 mg PO then 250 mg every 6 hr starting with the onset of bleeding. Can be initiated at start of menses and should not be necessary for longer than 2–3 days.
Pediatric patients
Safety and efficacy for patients younger than 14 yr not established.
Geriatric patients
Use caution in treating patients 65 yr and older. Elderly patients are at greater risk for serious GI events.
Patients with renal impairment
Not recommended.
