Painnox

Painnox Uses, Dosage, Side Effects, Food Interaction and all others data.

Painnox, 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.

Painnox, 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 Painnox
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 Thailand
Last Updated: September 19, 2023 at 7:00 am
Painnox
Painnox

Uses

Painnox 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.

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

How Painnox works

Painnox 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

Painnox dosage

As with other NSAIDs, the lowest dose should be sought for each patient. Therefore, after observing the response to initial therapy with Painnox, 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 Painnox 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 Painnox 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

Painnox 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. Painnox, 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, Painnox 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. Painnox 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 Painnox 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

Painnox is contraindicated in patients with known hypersensitivity to Me Painnox acid. Painnox 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. Painnox 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 Painnox

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

FAQ

What is Painnox used for?

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

How safe is Painnox?

Painnox 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 Painnox work?

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

What are the common side effects of Painnox?

Common side effects of Painnox are include:

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

Is Painnox safe during pregnancy?

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

Is Painnox safe during breastfeeding?

Painnox passes into breast milk and is not recommended for use while breastfeeding.

Can I drink alcohol with Painnox?

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

Can I drive after taking Painnox?

Painnox 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 Painnox?

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

Is it safe to take Painnox?

Painnox should not be used for longer than 7 days.

How many times can I take Painnox?

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

How long does Painnox take to work?

If you wait until the symptoms have worsened,Painnox may not work as well. If you are using Painnox 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 Painnox to kick in?

Painnox takes between 2 - 4 hours to kick in and start easing your period pain. Each 500mg dose of Painnox 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 Painnox for a long time?

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

Who should not take Painnox?

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

What happens if I miss a dose on Painnox?

Take Painnox 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 Painnox?

If you take too much If you take too much Painnox, you may experience: drowsiness, nausea,vomiting.

When can I stop taking Painnox?

If you experience any of the following symptoms, stop taking Painnox 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 Painnox affects my heart ?

Painnox 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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