Mefenamic acid

Clinical summary

Indications and usage 1 INDICATIONS AND USAGE Mefenamic acid capsules are a nonsteroidal anti-inflammatory drug indicated for: For management of mild to moderate pain in patient 14 years of age and older, when therapy will not exceed one week (7 days). ( 1.1 ) For treatment of primary dysmenorrhea. ( 1.2 ) 1.1 Mild to Moderate Pain Mefenamic acid capsules are indicated for management of mild to moderate pain in adults and pediatric patients 14 years of age and older, when therapy will not exceed one week (7 days). 1.2 Dysmenorrhea Mefenamic acid capsules are indicated for treatment of primary dysmenorrhea. Dosage and administration 2 DOSAGE AND ADMINISTRATION Adults and adolescents 14 years of age and older: 500 mg given orally as an initial dose followed by 250 mg every 6 hours as needed ( 2.2 ) For the treatment of primary dysmenorrhea: 500 mg given orally as an initial dose followed by 250 mg every 6 hours ( 2.3 ) 2.1 Important Dosage and Administration Information Carefully consider the potential benefits and risks of mefenamic acid capsules and other treatment options before deciding to use mefenamic acid capsules. Use the lowest effective dose for the shortest duration consistent with individual patient treatment goals [see Warnings and Precautions (5.2) ] . After observing the response to initial therapy with mefenamic acid capsules, the dose and frequency should be adjusted to suit an individual patient's needs. 2.2 For the Management of Mild to Moderate Pain The recommended dosage in adults and pediatric patients 14 years of age and older is 500 mg given orally as an initial dose followed by 250 mg every 6 hours as needed. 2.3 Dysmenorrhea The recommended dose is 500 mg given orally as an initial dose followed by 250 mg every 6 hours starting with the onset of bleeding and associated symptoms. Warnings and cautions 5 WARNINGS AND PRECAUTIONS Hepatotoxicity : Inform patients of warning signs and symptoms of hepatotoxicity. Discontinue if abnormal liver tests persist or worsen or if clinical signs and symptoms of liver disease develop. ( 5.3 ) Hypertension : Patients taking some antihypertensive medications may have impaired response to these therapies when taking NSAIDs. Monitor blood pressure. ( 5.4 , 7 ) Heart Failure and Edema : Avoid use of mefenamic acid in patients with severe heart failure unless benefits are expected to outweigh risk of worsening heart failure. ( 5.5 ) Renal Toxicity : Monitor renal function in patients with renal or hepatic impairment, heart failure, dehydration, or hypovolemia. Avoid use of mefenamic acid in patients with advanced renal disease unless benefits are expected to outweigh risk of worsening renal function. ( 5.6 ) Anaphylactic Reactions : Seek emergency help if an anaphylactic reaction occurs. ( 5.7 ) Exacerbation of Asthma Related to Aspirin Sensitivity: Mefenamic acid is contraindicated in patients with aspirin-sensitive asthma. Monitor patients with preexisting asthma (without aspirin sensitivity). ( 5.8 ) Serious Skin Reactions : Discontinue mefenamic acid at first appearance of skin rash or other signs of hypersensitivity. ( 5.9 ) Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) : Discontinue and evaluate clinically. ( 5.10 ) Fetal Toxicity : Limit use of NSAIDs, including mefenamic acid, between about 20 to 30 weeks in pregnancy due to the risk of oligohydramnios/fetal renal dysfunction. Avoid use of NSAIDs in women at about 30 weeks gestation and later in pregnancy due to the risks of oligohydramnios/fetal renal dysfunction and premature closure of the fetal ductus arteriosus. ( 5.11 , 8.1 ) Hematologic Toxicity : Monitor hemoglobin or hematocrit in patients with any signs or symptoms of anemia. ( 5.12 , 7 ) 5.1 Cardiovascular Thrombotic Events Clinical trials of several COX-2 selective and nonselective NSAIDs of up to three years duration have shown an increased risk of serious cardiovascular (CV) thrombotic events, including myocardial infarction (MI) and stroke, which can be fatal. Based on available data, it is unclear that the risk for CV thrombotic events is similar for all NSAIDs. The relative increase in serious CV thrombotic events over baseline conferred by NSAID use appears to be similar in those with and without known CV disease or risk factors for CV disease. However, patients with known CV disease or risk factors had a higher absolute incidence of excess serious CV thrombotic events, due to their increased baseline rate. Some observational studies found that this increased risk of serious CV thrombotic events began as early as the first weeks of treatment. The increase in CV thrombotic risk has been observed most consistently at higher doses. To minimize the potential risk for an adverse CV event in NSAID-treated patients, use the lowest effective dose for the shortest duration possible. Physicians and patients should remain alert for the development of such events throughout the entire treatment course, even in the absence o