Pharex Mefenamic Acid

Pharex Mefenamic Acid Uses, Dosage, Side Effects, Food Interaction and all others data.

Pharex Mefenamic Acid, an anthranilic acid derivative, is a prototypical NSAID. It reversibly inhibits the cyclooxygenase-1 and cyclooxygenase-2 (COX-1 and COX-2) enzymes, thus resulting in reduced synthesis of prostaglandin precursors. It has analgesic and antipyretic properties with minor anti-inflammatory activity.

Pharex Mefenamic Acid, an anthranilic acid derivative, is a member of the fenamate group of nonsteroidal anti-inflammatory drugs (NSAIDs). It exhibits anti-inflammatory, analgesic, and antipyretic activities. Similar to other NSAIDs, mefenamic acid inhibits prostaglandin synthetase.

Trade Name Pharex Mefenamic Acid
Generic Mefenamic acid
Mefenamic acid Other Names Acide méfénamique, ácido mefenámico, Acidum mefenamicum, Mefenamic acid, Mefenaminsäure
Type
Formula C15H15NO2
Weight Average: 241.2851
Monoisotopic: 241.110278729
Protein binding

90%

Groups Approved
Therapeutic Class Drugs for Osteoarthritis, Drugs used for Rheumatoid Arthritis, Non-steroidal Anti-inflammatory Drugs (NSAIDs)
Manufacturer
Available Country Philippines
Last Updated: September 19, 2023 at 7:00 am
Pharex Mefenamic Acid
Pharex Mefenamic Acid

Uses

Pharex Mefenamic Acid is used in mild to moderate pain including headache, dental pain, postoperative and postpartum pain, dysmenorrhoea, menorrhagia, in musculoskeletal and joint disorders such as osteoarthritis and rheumatoid arthritis; and in children with fever and juvenile idiopathic arthritis.

Pharex Mefenamic Acid is also used to associated treatment for these conditions: Mild pain, Primary Dysmenorrhoea, Gastrointestinal cramps, Moderate Pain

How Pharex Mefenamic Acid works

Pharex Mefenamic Acid binds the prostaglandin synthetase receptors COX-1 and COX-2, inhibiting the action of prostaglandin synthetase. As these receptors have a role as a major mediator of inflammation and/or a role for prostanoid signaling in activity-dependent plasticity, the symptoms of pain are temporarily reduced.

Dosage

Pharex Mefenamic Acid dosage

As with other NSAIDs, the lowest dose should be sought for each patient. Therefore, after observing the response to initial therapy with Pharex Mefenamic Acid, the dose and frequency should be adjusted to suit an individual patient's needs.Administration is by the oral route, preferably with food.

  • Adult: A 500 mg dose should be given to adults up to three times (1.5 g total) per day.
  • Infants over 6 months: 25 mg/kg of body weight daily in divided doses for not longer than 7 days.

Side Effects

In patients taking Pharex Mefenamic Acid or other NSAIDs, the most frequently reported adverse experiences include : abdominal pain, constipation, diarrhoea, dyspepsia, flatulence, gross bleeding/perforation, heartburn, nausea, GI ulcers, vomiting, abnormal renal function, anaemia, dizziness, oedema, elevated liver enzymes, headache, increased bleeding time, pruritus, rash and tinnitus.

Toxicity

Oral, rat LD50: 740 mg/kg. Symptoms of overdose may include severe stomach pain, coffee ground-like vomit, dark stool, ringing in the ears, change in amount of urine, unusually fast or slow heartbeat, muscle weakness, slow or shallow breathing, confusion, severe headache or loss of consciousness.

Precaution

NSAIDs should be prescribed with extreme caution in those with a prior history of ulcer disease or gastrointestinal bleeding. To minimise the potential risk for an adverse GI event, the lowest effective dose should be used for the shortest possible duration. In cases with pre-existing advanced kidney disease, treatment with Pharex Mefenamic Acid is not recommended.

Interaction

Concomitant use with CYP2C9 isoenzyme inhibitors may alter safety and efficacy of mefenamic acid. May enhance methotrexate toxicity. Reduced BP response to ACE inhibitors or angiotensin II receptor antagonists. Increased risk of serious GI events with aspirin. May reduce the natriuretic effects of furosemide or thiazide diuretics. Reduced renal lithium clearance and elevated plasma lithium levels. May enhance anticoagulant effect of warfarin.

Food Interaction

  • Avoid alcohol.
  • Take with food.

Volume of Distribution

  • 1.06 L/kg [Normal Healthy Adults (18-45 yr)]

Elimination Route

Pharex Mefenamic Acid is rapidly absorbed after oral administration.

Half Life

2 hours

Clearance

  • Oral cl=21.23 L/hr [Healthy adults (18-45 yrs)]

Elimination Route

The fecal route of elimination accounts for up to 20% of the dose, mainly in the form of unconjugated 3-carboxymefenamic acid.3 The elimination half-life of mefenamic acid is approximately two hours. Pharex Mefenamic Acid, its metabolites and conjugates are primarily excreted by the kidneys. Both renal and hepatic excretion are significant pathways of elimination.

Pregnancy & Breastfeeding use

Pregnancy: In late pregnancy, as with other NSAIDs, Pharex Mefenamic Acid should be avoided because it may cause premature closure of the ductus arteriosus. In general there are no adequate and well controlled studies in pregnant women. Pharex Mefenamic Acid should be used during pregnancy only if the potential benefit justifies the potential risk to the foetus. Rated as Pregnancy Category C.

Lactation: Trace amounts of Pharex Mefenamic Acid may be present in breast milk. Taking into account the importance of the drug to the mother , decision should be made whether to discontinue nursing or to discontinue the drug.

Contraindication

Pharex Mefenamic Acid is contraindicated in patients with known hypersensitivity to Me Pharex Mefenamic Acid acid. Pharex Mefenamic Acid should not be given to patients who have experienced asthma, urticaria, or allergic type reactions after taking aspirin or other NSAIDs. Rarely fatal, anaphylactic like reactions to NSAIDs have been reported in such patients. Pharex Mefenamic Acid is contraindicated in patients with active ulceration or chronic inflammation of upper gastrointestinal tract and should not be used in patients with preexisting renal disease.

Acute Overdose

Symptoms: Headache, nausea, vomiting, epigastric pain, GI bleeding. Rarely, diarrhoea, disorientation, excitation, coma, drowsiness, tinnitus, fainting, and occasionally convulsions.

Management: Symptomatic and supportive treatment. In acute overdosage, empty the stomach immediately by inducing emesis or by gastric lavage followed by admin of activated charcoal.

Storage Condition

Store between 20-25° C.

Innovators Monograph

You find simplified version here Pharex Mefenamic Acid

Pharex Mefenamic Acid contains Mefenamic acid see full prescribing information from innovator Pharex Mefenamic Acid Monograph, Pharex Mefenamic Acid MSDS, Pharex Mefenamic Acid FDA label

FAQ

What is Pharex Mefenamic Acid used for?

Pharex Mefenamic Acid is used short-term to treat mild to moderate pain in adults and children who are at least 14 years old.

How safe is Pharex Mefenamic Acid?

Pharex Mefenamic Acid may increase your risk of heart problems, including heart attack, stroke, heart failure, or blood clot. These conditions can be fatal. Your risk may increase if you already have heart disease or have taken the medication for a long period of time or at high doses.

How does Pharex Mefenamic Acid work?

Pharex Mefenamic Acid works by stopping the body's production of a substance that causes pain, fever, and inflammation.

What are the common side effects of Pharex Mefenamic Acid?

Common side effects of Pharex Mefenamic Acid are include:

  • diarrhea.
  • constipation.
  • gas or bloating.
  • headache.
  • dizziness.
  • nervousness.
  • ringing in the ears

Is Pharex Mefenamic Acid safe during pregnancy?

Use of Pharex Mefenamic Acid during pregnancy is not advised unless prescribed by a doctor, especially if you are 30 or more weeks pregnant.

Is Pharex Mefenamic Acid safe during breastfeeding?

Pharex Mefenamic Acid passes into breast milk and is not recommended for use while breastfeeding.

Can I drink alcohol with Pharex Mefenamic Acid?

Do not drink alcohol while taking Pharex Mefenamic Acid. Alcohol can increase your risk of stomach bleeding caused by Pharex Mefenamic Acid. Call your doctor at once if you have symptoms of bleeding in your stomach or intestines.

Can I drive after taking Pharex Mefenamic Acid?

Pharex Mefenamic Acid Tablets may cause drowsiness, fatigue, dizziness or may affect your vision. If you experience any of these symptoms, you should not drive or operate machinery, or perform any tasks which may require you to be alert.

When should be taken of Pharex Mefenamic Acid?

Pharex Mefenamic Acid is usually taken with food every 6 hours as needed for up to 1 week.

Is it safe to take Pharex Mefenamic Acid?

Pharex Mefenamic Acid should not be used for longer than 7 days.

How many times can I take Pharex Mefenamic Acid?

Pharex Mefenamic Acid take 250 mg every six hours as needed. You shouldn't take Pharex Mefenamic Acid for longer than three days.

How long does Pharex Mefenamic Acid take to work?

If you wait until the symptoms have worsened,Pharex Mefenamic Acid may not work as well. If you are using Pharex Mefenamic Acid for painful periods, take your first dose as soon as your period starts or pain begins. Usually, you will only need to take it for the first 2 to 3 days of your period.

How long does it take for Pharex Mefenamic Acid to kick in?

Pharex Mefenamic Acid takes between 2 - 4 hours to kick in and start easing your period pain. Each 500mg dose of Pharex Mefenamic Acid kills pain for up to 8 hours, so you may need to take it two or three times a day for all-day relief.

Can I take Pharex Mefenamic Acid for a long time?

Pharex Mefenamic Acid should not be used for longer than 7 days. Follow your doctor's dosing instructions very carefully. If you use Pharex Mefenamic Acid long-term, you may need frequent medical tests.Pharex Mefenamic Acid can cause unusual results with certain medical tests.

Who should not take Pharex Mefenamic Acid?

Pharex Mefenamic Acid can increase your risk of fatal heart attack or stroke. Do not use Pharex Mefenamic Acid just before or after heart bypass surgery .Pharex Mefenamic Acid may also cause stomach or intestinal bleeding, which can be fatal.

What happens if I miss a dose on Pharex Mefenamic Acid?

Take Pharex Mefenamic Acid as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happen if I take too much Pharex Mefenamic Acid?

If you take too much If you take too much Pharex Mefenamic Acid, you may experience: drowsiness, nausea,vomiting.

When can I stop taking Pharex Mefenamic Acid?

If you experience any of the following symptoms, stop taking Pharex Mefenamic Acid and call your doctor: stomach pain, heartburn, vomit that is bloody or looks like coffee grounds, blood in the stool, or black and tarry stools.

Can Pharex Mefenamic Acid affects my heart ?

Pharex Mefenamic Acid can increase your risk of fatal heart attack or stroke, especially if you use it long term or take high doses, or if you have heart disease.

*** Taking medicines without doctor's advice can cause long-term problems.
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