More frequently reported side effects include: abdominal pain, diarrhea, and nausea. See below for a comprehensive list of adverse effects.
Applies to mefenamic acid: oral capsule
Oral route (Capsule)
NSAIDs cause an increased risk of serious cardiovascular thrombotic events, including myocardial infarction and stroke, which can be fatal. This risk may occur early in treatment and may increase with duration of use. Mefenamic acid is contraindicated in the setting of CABG surgery. NSAIDs can also cause an increased risk of serious gastrointestinal (GI) adverse events including bleeding, ulceration, and perforation of the stomach or intestines, which can be fatal. These events can occur at any time during use and without warning symptoms. Elderly patients and patients with a prior history of peptic ulcer disease or GI bleeding are at greater risk for serious GI events.
Along with its needed effects, mefenamic acid may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur while taking mefenamic acid:
Get emergency help immediately if any of the following symptoms of overdose occur while taking mefenamic acid:
Symptoms of overdose
Some side effects of mefenamic acid may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
Applies to mefenamic acid: oral capsule
Common (1% to 10%): Abdominal pain, constipation, diarrhea, dyspepsia, flatulence, gross bleeding/perforation, heartburn, nausea, gastric ulcers, duodenal ulcers, vomiting
Rare (less than 0.1%): Eructation, pancreatitis
Frequency not reported: Peptic ulcer, dry mouth, esophagitis, gastritis, GI bleeding, glossitis, hematemesis, melena, rectal bleeding, stomatitis, anorexia, colitis, enterocolitis, pyrosis, steatorrhea, GI inflammation, ulcerative stomatitis, exacerbation of Crohn's disease, gastritis
The most frequently reported side effects were gastrointestinal (GI) in nature and included abdominal pain, constipation, diarrhea, dyspepsia, flatulence, gross bleeding/perforation, heartburn, nausea, vomiting, and gastric or duodenal ulcers.
Rare (less than 0.1%): Hypotension, arrhythmia, myocardial infarction, palpitations, vasculitis
Frequency not reported: Congestive heart failure, tachycardia, hypertension, cardiac failure, arterial thrombotic events
Cases of autoimmune hemolytic anemia have been reported with continuous use of this drug for 12 months or longer. In such cases, the Coombs tests were positive for both accelerated RBC production and destruction. The process was reversible upon discontinuation of therapy.
Common (1% to 10%): Anemia, bleeding time increased
Rare (less than 0.1%): Agranulocytosis, hemolytic anemia, aplastic anemia, lymphadenopathy, pancytopenia
Frequency not reported: Eosinophilia, leukopenia, thrombocytopenia, bone marrow hypoplasia, hematocrit decreased, thrombocytopenic purpura, disseminated intravascular coagulation, neutropenia, autoimmune hemolytic anemia, eosinophilia, platelet aggregation inhibition
Rare (less than 0.1%): Hyperglycemia
Frequency not reported: Hyponatremia, glucose intolerance, anorexia
Common (1% to 10%): Dizziness, headache, drowsiness
Rare (less than 0.1%): Convulsions, coma
Frequency not reported: Syncope, paresthesia, somnolence, tremors, optic neuritis
Rare (less than 0.1%): Respiratory distress, pneumonia
Frequency not reported: Asthma, dyspnea, bronchospasm, aggravated asthma, laryngeal edema
Common (1% to 10%): Rash, pruritus
Rare (less than 0.1%): Angioedema, toxic epidermal necrolysis, Stevens-Johnson syndrome, erythema multiforme, exfoliative dermatitis, urticaria
Frequency not reported: Ecchymosis, purpura, alopecia, photosensitivity, sweating
Common (1% to 10%): Elevated liver enzymes
Rare (less than 0.1%): Liver failure
Frequency not reported: Hepatitis, jaundice, cholestatic jaundice, hepatorenal syndrome, mild hepatic toxicity
Rare (less than 0.1%): Conjunctivitis
Frequency not reported: Blurred vision, eye irritation, reversible loss of color vision, visual disturbances
Frequency not reported: Cystitis, dysuria, hematuria, oliguria, polyuria, proteinuria, false positive urobilinogen urine
Common (1% to 10%): Abnormal renal function
Frequency not reported: Interstitial nephritis, renal failure, allergic/non-allergic glomerulonephritis, nephrotic syndrome, non-oliguric renal failure, renal papillary necrosis, tubulointerstitial nephritis
Rare (less than 0.1%): Hallucinations
Frequency not reported: Anxiety, confusion, depression, dream abnormalities, insomnia, nervousness
Rare (less than 0.1%): Anaphylactoid/anaphylactic reaction
Frequency not reported: Hypersensitivity reaction, non-specific allergic reaction
Common (1% to 10%): Edema, tinnitus
Rare (less than 0.1%): Death, meningitis, appetite changes, hearing impairment
Frequency not reported: Fever, infection, sepsis, weight changes, asthenia, malaise, vertigo, aseptic meningitis, ear pain, face edema, fatigue, malaise, multi-organ failure, pyrexia, fluid retention, edema of the larynx
Medically reviewed by BestRx Medical Team Last updated on 1/1/2020.
Source: Drugs.com Mefenamic Acid