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FDA Drug information

Mefenamic Acid

Read time: 1 mins
Marketing start date: 05 May 2024

Summary of product characteristics


Adverse Reactions

The following adverse reactions are discussed in greater detail in other sections of the labeling: Cardiovascular Thrombotic Events ( see WARNINGS) GI Bleeding, Ulceration and Perforation ( see WARNINGS) Hepatotoxicity ( see WARNINGS) Hypertension ( see WARNINGS) Heart Failure and Edema ( see WARNINGS) Renal Toxicity and Hyperkalemia ( see WARNINGS) Anaphylactic Reactions ( see WARNINGS) Serious Skin Reactions ( see WARNINGS) Hematologic Toxicity ( see WARNINGS) Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. In patients taking mefenamic acid or other NSAIDs, the most frequently reported adverse experiences occurring in approximately 1 to 10% of patients are: Gastrointestinal experiences including - abdominal pain, constipation, diarrhea, dyspepsia, flatulence, gross bleeding/perforation, heartburn, nausea, GI ulcers (gastric/duodenal), vomiting, abnormal renal function, anemia, dizziness, edema, elevated liver enzymes, headaches, increased bleeding time, pruritus, rashes, tinnitus Additional adverse experiences reported occasionally and listed here by body system include: Body as a whole - fever, infection, sepsis Cardiovascular system - congestive heart failure, hypertension, tachycardia, syncope Digestive system - dry mouth, esophagitis, gastric/peptic ulcers, gastritis, gastrointestinal bleeding, glossitis, hematemesis, hepatitis, jaundice Hemic and lymphatic system - ecchymosis, eosinophilia, leukopenia, melena, purpura, rectal bleeding, stomatitis, thrombocytopenia Metabolic and nutritional - weight changes Nervous system - anxiety, asthenia, confusion, depression, dream abnormalities, drowsiness; insomnia, malaise, nervousness, paresthesia, somnolence, tremors, vertigo Respiratory system - asthma, dyspnea Skin and appendages - alopecia, photosensitivity, pruritus, sweat Special senses - blurred vision Urogenital system - cystitis, dysuria, hematuria, interstitial nephritis, oliguria/polyuria, proteinuria, renal failure Other adverse reactions, which occur rarely are: Body as a whole - anaphylactoid reactions, appetite changes, death Cardiovascular system - arrhythmia, hypotension, myocardial infarction, palpitations, vasculitis Digestive system - eructation, liver failure, pancreatitis Hemic and lymphatic system - agranulocytosis, hemolytic anemia, aplastic anemia, lymph­ adenopathy, pancytopenia Metabolic and nutritional - hyperglycemia Nervous system - convulsions, coma, hallucinations, meningitis Respiratory - respiratory depression, pneumonia Skin and appendages - angioedema, toxic epidermal necrosis, erythema multiforme, exfoliative dermatitis, Stevens - Johnson syndrome, urticaria Special senses - conjunctivitis, hearing impairment To report SUSPECTED ADVERSE REACTIONS, contact Micro Labs USA, Inc. at 1-855-839-8195 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

Contraindications

Mefenamic acid is contraindicated in the following patients: Known hypersensitivity (e.g., anaphylactic reactions and serious skin reactions) to mefenamic acid or any components of the drug product ( see WARNINGS; ANAPHYLACTIC REACTIONS, SERIOUS SKIN REACTIONS) . History of asthma, urticaria, or other allergic-type reactions after taking aspirin or other NSAIDs. Severe, sometimes fatal, anaphylactic reactions to NSAIDs have been reported in such patients ( see WARNINGS; ANAPHYLACTIC REACTION, EXACERBATION OF ASTHMA RELATED TO ASPIRIN SENSITIVITY) . In the setting of coronary artery bypass graft (CABG) surgery (see WARNINGS; CARDIOVASCULAR THROMBOTIC EVENTS) .

Description

Mefenamic Acid Capsules are a member of the fenamate group of nonsteroidal anti-inflammatory drugs (NSAIDs). Each Size '1' Yellow-Yellow capsule, with 'ML' imprinted on the cap & '250' imprinted on the body, contains 250 mg of mefenamic acid for oral administration. Mefenamic acid is a white to greyish-white, odorless, microcrystalline powder with a melting point of 230° to 231°C and water solubility of 0.004% at pH 7.1. The chemical name is N-2,3-xylylanthranilic acid. The molecular weight is 241.29. Its molecular formula is C 15H 15NO 2 and the structural formula of mefenamic acid is: Each capsule also contains lactose monohydrate. The capsule shell contains D&C yellow No. 10; FD&C blue No. 1; FD&C red No. 3; FD&C yellow No. 6; gelatin, sodium lauryl sulfate, titanium dioxide, black iron oxide, propylene glycol & shellac. Description

Dosage And Administration

Carefully consider the potential benefits and risks of mefenamic acid and other treatment options before deciding to use mefenamic acid. Use the lowest effective dose for the shortest duration consistent with individual patient treatment goals (see WARNINGS; GASTROINTESTINAL BLEEDING, ULCERATION, AND PERFORATION). After observing the response to initial therapy with mefenamic acid, the dose and frequency should be adjusted to suit an individual patient's needs. For the relief of acute pain in adults and adolescents ≥14 years of age, the recommended dose is 500 mg as an initial dose followed by 250 mg every 6 hours as needed, usually not to exceed one week. For the treatment of primary dysmenorrhea, the recommended dose is 500 mg as an initial dose followed by 250 mg every 6 hours, given orally, starting with the onset of bleeding and associated symptoms. Clinical studies indicate that effective treatment can be initiated with the start of menses and should not be necessary for more than 2 to 3 days.

Indications And Usage

Carefully consider the potential benefits and risks of mefenamic acid and other treatment options before deciding to use mefenamic acid. Use the lowest effective dose for the shortest duration consistent with individual patient treatment goals ( see WARNINGS; GASTROINTESTINAL BLEEDING, ULCERATION, AND PERFORATION). Mefenamic acid is indicated: For relief of mild to moderate pain in patients ≥ 14 years of age, when therapy will not exceed one week (7 days). For treatment of primary dysmenorrhea.

Overdosage

Symptoms following acute NSAID overdosages have been typically limited to lethargy, drowsiness, nausea, vomiting, and epigastric pain, which have been generally reversible with supportive care. Gastrointestinal bleeding has occurred. Hypertension, acute renal failure, respiratory depression and coma have occurred, but were rare (see WARNINGS; CARDIOVASCULAR THROMBOTIC EVENTS, GASTROINTESTINAL BLEEDING, ULCERATION, AND PERFORATION, HYPERTENSION, RENAL TOXICITY AND HYPERKALEMIA). Manage patients with symptomatic and supportive care following an NSAID overdosage. There are no specific antidotes. Consider emesis and/or activated charcoal (60 to 100 grams in adults, 1 to 2 grams per kg of body weight in pediatric patients) and/or osmotic cathartic in symptomatic patients seen within four hours of ingestion or in patients with a large overdose (5 to 10 times the recommended dosage). Forced diuresis, alkalinization of urine, hemodialysis, or hemoperfusion may not be useful due to high protein binding. For additional information about overdosage treatment, contact a poison control center (1-800-222-1222).

Clinical Pharmacology

Mechanism of Action Mefenamic acid has analgesic, anti-inflammatory, and antipyretic properties. The mechanism of action of mefenamic acid, like that of other NSAIDs, is not completely understood but involves inhibition of cyclooxygenase (COX-1 and COX-2). Mefenamic acid is a potent inhibitor of prostaglandin synthesis in vitro. Mefenamic acid concentrations reached during therapy have produced in vivo effects. Prostaglandins sensitize afferent nerves and potentiate the action of bradykinin in inducing pain in animal models. Prostaglandins are mediators of inflammation. Because mefenamic acid is an inhibitor of prostaglandin synthesis, its mode of action may be due to a decrease of prostaglandins in peripheral tissues. Pharmacokinetics Absorption Mefenamic acid is rapidly absorbed after oral administration. In two 500-mg single oral dose studies, the mean extent of absorption was 30.5 mcg/hr/mL (17% CV). The bioavailability of the capsule relative to an IV dose or an oral solution has not been studied. Following a single 1-gram oral dose, mean peak plasma levels ranging from 10 to 20 mcg/mL have been reported. Peak plasma levels are attained in 2 to 4 hours and the elimination half-life approximates 2 hours. Following multiple doses, plasma levels are proportional to dose with no evidence of drug accumulation. In a multiple dose trial of normal adult subjects (n= 6) receiving 1-gram doses of mefenamic acid four times daily, steady-state concentrations of 20 mcg/mL were reached on the second day of administration, consistent with the short half-life. The effect of food on the rate and extent of absorption of mefenamic acid has not been studied. Concomitant ingestion of antacids containing magnesium hydroxide has been shown to significantly increase the rate and extent of mefenamic acid absorption (see PRECAUTIONS; DRUG INTERACTIONS). Distribution Mefenamic acid has been reported as being greater than 90% bound to albumin. The relationship of unbound fraction to drug concentration has not been studied. The apparent volume of distribution (Vzss/F) estimated following a 500-mg oral dose of mefenamic acid was 1.06 L/kg. Based on its physical and chemical properties, mefenamic acid is expected to be excreted in human breast milk (see PRECAUTIONS; NURSING MOTHERS). Elimination Metabolism Mefenamic acid is metabolized by cytochrome P450 enzyme CYP2C9 to 3-hydroxymethyl mefenamic acid (Metabolite I). Further oxidation to a 3-carboxymefenamic acid (Metabolite II) may occur. The activity of these metabolites has not been studied. The metabolites may undergo glucuronidation and mefenamic acid is also glucuronidated directly. A peak plasma level approximating 20 mcg/mL was observed at 3 hours for the hydroxy metabolite and its glucuronide (n= 6) after a single 1-gram dose. Similarly, a peak plasma level of 8 mcg/mL was observed at 6 to 8 hours for the carboxy metabolite and its glucuronide. Excretion Approximately fifty-two percent of a mefenamic acid dose is excreted into the urine primarily as glucuronides of mefenamic acid (6%), 3-hydroxymefenamic acid (25%) and 3­ carboxymefenamic acid (21%). The fecal route of elimination accounts for up to 20% of the dose, mainly in the form of unconjugated 3-carboxymefenamic acid. The elimination half-life of mefenamic acid is approximately two hours. Half-lives of metabolites I and II have not been precisely reported, but appear to be longer than the parent compound. The metabolites may accumulate in patients with renal or hepatic failure. The mefenamic acid glucuronide may bind irreversibly to plasma proteins. Because both renal and hepatic excretions are significant pathways of elimination, dosage adjustments in patients with renal or hepatic dysfunction may be necessary. Mefenamic acid should not be administered to patients with pre-existing renal disease or in patients with significantly impaired renal function ( see WARNINGS; RENAL TOXICITY AND HYPERKALEMIA) . TABLE 1. Pharmacokinetic Parameter Estimates for Mefenamic Acid PK Parameters Normal Healthy Adults (18 to 45 yr) Value CV T max (hr) 2 66 Oral clearance (L/hr) 21.13 38 Apparent volume of distribution; Vz/F (L/kg) 1.06 60 Half-life; t ½ (hrs) 2 to 4 N/A Special Populations Pediatric: Mefenamic acid has not been adequately investigated in pediatric patients less than 14 years of age. A study in 17 preterm infants administered 2 mg/kg indicated that the half-life was about five times as long as adults, consistent with the low activity of metabolic enzymes in newborn infants. The mean C max in this study was 4 mcg/mL (range 2.9 to 6.1). The mean time to maximum concentration (T max) was 8 hours (range 2 to 18 hours). Race: Pharmacokinetic differences due to race have not been identified. Hepatic Impairment: Mefenamic acid pharmacokinetics have not been studied in patients with hepatic dysfunction. As hepatic metabolism is a significant pathway of mefenamic acid elimination, patients with acute and chronic hepatic disease may require reduced doses of mefenamic acid compared to patients with normal hepatic function (see WARNINGS; HEPATOTOXICITY). Renal Impairment: Mefenamic acid pharmacokinetics have not been investigated in subjects with renal insufficiency. Given that mefenamic acid, its metabolites and conjugates are primarily excreted by the kidneys, the potential exists for mefenamic acid metabolites to accumulate. Mefenamic acid should not be administered to patients with pre-existing renal disease or in patients with significantly impaired renal function ( see WARNINGS; RENAL TOXICITY AND HYPERKALEMIA). Drug Interaction Studies Aspirin: When NSAIDs were administered with aspirin, the protein binding of NSAIDs were reduced, although the clearance of free NSAID was not altered. The clinical significance of this interaction is not known. See Table 2 for clinically significant drug interactions of NSAIDs with aspirin ( see PRECAUTIONS; DRUG INTERACTIONS) . Clinical Studies In controlled, double-blind, clinical trials, mefenamic acid was evaluated for the treatment of primary spasmodic dysmenorrhea. The parameters used in determining efficacy included pain assessment by both patient and investigator; the need for concurrent analgesic medication; and evaluation of change in frequency and severity of symptoms characteristic of spasmodic dysmenorrhea. Patients received either mefenamic acid, 500 mg (2 capsules) as an initial dose of 250 mg every 6 hours, or placebo at onset of bleeding or of pain, whichever began first. After three menstrual cycles, patients were crossed over to the alternate treatment for an additional three cycles. Mefenamic acid was significantly superior to placebo in all parameters, and both treatments (drug and placebo) were equally tolerated.

Clinical Pharmacology Table

PK Parameters Normal Healthy Adults (18 to 45 yr)
Value CV
T max (hr) 2 66
Oral clearance (L/hr) 21.13 38
Apparent volume of distribution; Vz/F (L/kg) 1.06 60
Half-life; t ½ (hrs) 2 to 4 N/A

Effective Time

20230406

Version

1

Spl Product Data Elements

Mefenamic Acid Mefenamic Acid MEFENAMIC ACID MEFENAMIC ACID ML;250

Application Number

ANDA090562

Brand Name

Mefenamic Acid

Generic Name

Mefenamic Acid

Product Ndc

80425-0306

Product Type

HUMAN PRESCRIPTION DRUG

Route

ORAL

Package Label Principal Display Panel

label 1 label 2 label 3

Spl Medguide

Medication Guide for Nonsteroidal Anti-inflammatory Drugs (NSAIDS) Mefenamic Acid (mef-e-NAM-ik AS-id) Capsules, USP 250 mg What is the most important information I should know about medicines called Nonsteroidal Anti-inflammatory Drugs (NSAIDs)? NSAID can cause serious side effects, including: Increase risk of a heart attack or stroke that can lead to death. This risk may happen early in treatment and may increase: with increasing doses of NSAIDs with longer use of NSAIDs Do not take NSAIDs right before or after a heart surgery called a “coronary artery bypass graft (CABG)". Avoid taking NSAIDs after a recent heart attack, unless your healthcare provider tells you to. You may have an increased risk of another heart attack if you take NSAIDs after a recent heart attack. Increase risk of bleeding, ulcers and tears (perforation) of the esophagus (tube leading from the mouth to the stomach), stomach and intestines: anytime during use without warning symptoms that may cause death The risk of getting an ulcer or bleeding increases with: past history of stomach ulcers, or stomach or intestinal bleeding with use of NSAIDs taking medicines called “corticosteroids”, “anticoagulants”, “SSRIs”, or “SNRIs” increasing doses of NSAIDs older age longer use of NSAIDs poor health smoking advanced liver disease drinking alcohol bleeding problems NSAID should only be used: exactly as prescribed at the lowest dose possible for your treatment or the shortest time needed What are NSAIDs? NSAIDs are used to treat pain and redness, swelling, and heat (inflammation) from medical conditions such as different types of arthritis, menstrual cramps, and other types of short-term pain. Who should not take NSAIDs? Do not take NSAIDs: if you have had an asthma attack, hives, or other allergic reaction with aspirin or any other NSAIDs. right before or after heart bypass surgery. Before taking NSAIDs, tell our healthcare provider about all of your medical conditions, including if you: have liver or kidney problems have high blood pressure have asthma are pregnant or plan to become pregnant. Taking NSAIDs at about 20 weeks of pregnancy or later may harm your unborn baby. If you need to take NSAIDs for more than 2 days when you are between 20 and 30 weeks of pregnancy, your healthcare provider may need to monitor the amount of fluid in your womb around your baby. You should not take NSAIDs after about 30 weeks of pregnancy are breastfeeding or plan to breastfeed Tell your healthcare provider about all of the medicines you take, including prescription or over-the-counter medicines, vitamins, or herbal supplements. NSAIDs and some other medicines can interact with each other and cause serious side effects. Do not start taking any new medicine without talking to your healthcare provider first. What are the possible side effects of NSAIDs? NSAIDs can cause serious side effects, including: See “What is the most important information I should know about medicines called Nonsteroidal Anti-inflammatory Drugs (NSAIDs)?” new or worse high blood pressure heart failure liver problems including liver failure kidney problem including kidney failure low red blood cells (anemia) life-threatening skin reactions life-threatening allergic reactions Other side effects if NSAIDs include: stomach pain, constipation, diarrhea, gas, heartburn, nausea, vomiting, and dizziness. Get emergency help right away if you get any of the following symptoms: shortness of breath or trouble breathing slurred speech chest pain swelling of the face or throat weakness in one part or side of your body Stop taking your NSAID and call your healthcare provider right away if you get any of the following symptoms: nausea vomit blood more tired or weaker than usual there is blood in the bowel movement or it is black and sticky like tar diarrhea unusual weight gain itching skin rash or blisters with fever your skin or eyes look yellow swelling of the arms, legs, hands, and feet indigestion or stomach pain flu-like symptoms If you take too much of your NSAID, call your healthcare provider or get medical help right away. These are not all of the possible side effects of NSAIDs. For more information, ask your healthcare provider or pharmacist about NSAIDs. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088. Other information about NSAIDs Aspirin is an NSAID medicine but it does not increase the chance of a heart attack. Aspirin can cause bleeding in the brain, stomach, and intestines. Aspirin can also cause ulcers in the stomach and intestines. Some NSAIDs are sold in lower doses without a prescription (over-the-counter). Talk to your healthcare provider before using over-the-counter NSAID for more than 10 days. General information about the safe and effective use of NSAIDs Medicines are sometimes prescribed for purposes other than those listed in a Medication Guide. Do not use NSAIDs for a condition for which it was not prescribed. Do not give NSAIDs to other people, even if they have the same symptoms that you have. It may harm them. If you would like more information about NSAIDs, talk with your healthcare provider. You can ask your pharmacist or healthcare provider for information about NSAIDs that is written for health professionals. For more information, call 1-855-839-8195 This Medication Guide has been approved by the U.S. Food and Drug Administration. Manufactured by: Micro Labs Limited Goa- 403 722, INDIA. Manufactured for: Micro Labs USA, Inc. Somerset, NJ 08873 Rev.11/2021

How Supplied

Mefenamic Acid Capsules USP 250 mg are Size ‘1’ yellow-yellow capsules with ‘ML’ imprinted on the cap & ‘250’ imprinted on the body. They are supplied as follows: Bottles of 30 Capsules NDC: 80425-0306-01 Bottles of 60 Capsules NDC: 80425-0306-02 Bottles of 90 Capsules NDC: 80425-0306-03 Dispense in a tight container as defined in the USP. Storage Store at room temperature 20° to 25°C (68° to 77°F); excursions permitted between 15° to 30°C (59° to 86°F) [see USP Controlled Room Temperature]. For inquiries call 1-855-839-8195 Manufactured by: Micro Labs Limited Goa- 403 722, INDIA. Manufactured for: Micro Labs USA, Inc. Somerset, NJ 08873

Boxed Warning

WARNING: RISK OF SERIOUS CARDIOVASCULAR AND GASTROINTESTINAL EVENTS Cardiovascular Thrombotic Events Nonsteroidal anti-inflammatory drugs (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 ( see WARNINGS). Mefenamic acid is contraindicated in the setting of coronary artery bypass graft (CABG) surgery (see CONTRAINDICATIONS, WARNINGS). Gastrointestinal Bleeding, Ulceration, and Perforation NSAIDs 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 and/or GI bleeding are at greater risk for serious GI events (see WARNINGS).

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