About Mefenamic Acid NSAID, Analgesic,antiinflammatory. Mechanism of Action of Mefenamic Acid Mefenamic acid has analgesic, anti-inflammatory and antipyretic action. It acts by inhibiting Prostaglandin (PGs) synthesis and their release at the site of injury. Prostaglandins cause tenderness and amplify the action of other analgesics. Mefenamic acid inhibits cyclo-oxygenase enzyme and antagonizes prostaglandin actions. Indications for Mefenamic Acid 1.Muscular aches 2.Primary Dysmenorrhoea 3.Headaches 4.Acute gout 5.Dental pain 6.Patent ductus arteriosus Typical Dosage for Mefenamic Acid Adult: initial dose: 500 mg followed by 250 mg every 6 hours. Treatment is continued maximum up to 1 week. Children above 14 years: 500 mg followed by 250 mg every 6 hours. Treatment is continued maximum up to 1 week. Children below 14 years: not recommended.