Mefenamic acid

Menorrhagia, Dysmenorrhea ... show more

Drug Status

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Government Approvals

US(FDA), UK(BNF)

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WHO Essential Medicine

NO

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Known Teratogen

Possible

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Pharmaceutical Class

Nonsteroidal Anti-inflammatory Drug

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Controlled Drug Substance

NO

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Drug Ingredient

Mefenamic acid

Summary

  • Mefenamic acid is used for the relief of mild to moderate pain such as headaches, dental pain, muscle pain, and menstrual cramps. It's also used in the treatment of inflammatory conditions like arthritis and can provide short-term relief of fever in some cases.

  • Mefenamic acid is a pain reliever and anti-inflammatory medicine. It works by stopping the body from making substances that cause pain and swelling. It's quickly absorbed when taken orally, with its effects lasting for a couple of hours.

  • For adults and teens 14 and older, you start with a large dose (500mg), then take smaller doses (250mg) every six hours as needed, but only for up to a week for sudden sharp pain. For period pain, start with the large dose when your period starts and take smaller doses every six hours for two or three days.

  • Mefenamic acid can cause stomach upset, nausea, heartburn, and may affect sleep. It can sometimes cause headaches, skin rashes, dizziness, and swelling. Rarely, it can lead to serious effects like heart attacks, strokes, severe liver damage, and severe skin reactions.

  • Mefenamic acid should not be taken if you're allergic to it or similar medicines like aspirin. It can increase your chances of a heart attack, stroke or bleeding. It's risky around heart surgery and can cause stomach and intestinal problems. It should not be taken during pregnancy, especially after 20 weeks, and only small amounts can pass to a baby through breast milk.

Indications and Purpose

How does Mefenamic acid work?

Mefenamic acid works by inhibiting the enzymes COX-1 and COX-2, which are involved in the production of prostaglandins. Prostaglandins are substances that cause inflammation, pain, and fever, so by reducing their production, Mefenamic acid alleviates these symptoms.

Is Mefenamic acid effective?

Clinical trials have shown that Mefenamic acid is effective in treating mild to moderate pain, including menstrual pain. It works by inhibiting the production of substances in the body that cause inflammation and pain, providing relief from symptoms.

What is Mefenamic acid?

Mefenamic acid is a nonsteroidal anti-inflammatory drug (NSAID) used to relieve mild to moderate pain, including menstrual pain. It works by inhibiting the production of substances in the body that cause inflammation and pain, providing relief from symptoms.

Directions for Use

For how long do I take Mefenamic acid?

Mefenamic acid is typically used for short-term relief of pain, usually not exceeding one week. For menstrual pain, it is often taken at the onset of symptoms and continued for 2 to 3 days as needed.

How do I dispose of Mefenamic acid?

If you can, bring unused medicines to a drug take-back program or collection site at a pharmacy or hospital. They will dispose of this medicine properly so they don't harm people or the environment. If you can't find a take-back program, you can throw most medicines in the trash at home. But first, take them out of their original containers, mix them with something undesirable like used coffee grounds, seal the mixture in a plastic bag and throw it away.

How do I take Mefenamic acid?

Take Mefenamic acid with food to reduce the risk of gastrointestinal upset. There are no specific food restrictions, but avoid alcohol to minimize the risk of stomach bleeding.

How long does it take for Mefenamic acid to start working?

Mefenamic acid typically starts working within 2 to 4 hours after taking a dose, providing relief from pain and inflammation.

How should I store Mefenamic acid?

Store Mefenamic acid in its original container, tightly closed, at room temperature away from excess heat and moisture. Keep it out of reach of children to prevent accidental ingestion.

What is the usual dose of Mefenamic acid?

For adults and adolescents aged 14 years and older, the usual dose of Mefenamic acid is 500 mg as an initial dose, followed by 250 mg every 6 hours as needed, typically not exceeding one week. For children under 14, safety and effectiveness have not been established, so consult a doctor for appropriate dosing.

Warnings and Precautions

Can I take Mefenamic acid with other prescription drugs?

Mefenamic acid can interact with anticoagulants, other NSAIDs, SSRIs, and SNRIs, increasing the risk of bleeding. It may also affect the efficacy of antihypertensives and diuretics. Always inform your doctor of all medications you are taking to avoid adverse interactions.

Can Mefenamic acid be taken safely while breastfeeding?

Trace amounts of Mefenamic acid may be present in breast milk. Due to potential risks to the nursing infant, consult your doctor to weigh the benefits and risks before using this medication while breastfeeding.

Can Mefenamic acid be taken safely while pregnant?

Mefenamic acid is not recommended during pregnancy, especially after 20 weeks, due to risks of fetal harm such as premature closure of the ductus arteriosus and renal dysfunction. Consult your doctor for safer alternatives if you are pregnant or planning to become pregnant.

Does Mefenamic acid have adverse effects?

Adverse effects are unwanted or harmful effects caused by a medicine. Mefenamic acid can cause stomach pain, nausea, diarrhea, and headaches, which are common. Rare but serious effects include severe allergic reactions, liver problems, or bleeding in the stomach. If you experience severe symptoms like difficulty breathing or severe stomach pain, seek medical help immediately. Always report new symptoms to your healthcare provider and consult them before stopping the medicine.

Does Mefenamic acid have any safety warnings?

Mefenamic acid has safety warnings, including the risk of stomach bleeding, especially if taken in high doses or for a long time. It can also increase the risk of heart attack or stroke. Symptoms to watch for include severe stomach pain, black stools, or chest pain. If you experience these, seek medical help immediately. It's important to use the lowest effective dose for the shortest time possible and to follow your doctor's instructions closely.

Is it safe to drink alcohol while taking Mefenamic acid?

Drinking alcohol while taking Mefenamic acid can increase the risk of gastrointestinal bleeding, ulcers, or holes in the stomach or intestine. It's advisable to limit or avoid alcohol consumption to reduce these risks.

Is it safe to exercise while taking Mefenamic acid?

Mefenamic acid does not specifically limit the ability to exercise. However, if you experience side effects like dizziness or shortness of breath, it may be wise to avoid strenuous activities and consult your doctor for advice.

Is it safe to stop Mefenamic acid?

Mefenamic acid is typically used for short-term relief of pain or inflammation, not for chronic conditions. Stopping it suddenly is generally safe, but you might experience a return of pain or symptoms. There are no known withdrawal symptoms or life-threatening risks from stopping it abruptly. However, it's always best to consult with your doctor before stopping any medication to ensure it's appropriate for your situation.

Is Mefenamic acid addictive?

Mefenamic acid is not addictive and has no known potential for dependence. It does not cause physical or psychological dependence, so there are no specific behaviors or warning signs to watch for. You can use it as prescribed without worrying about addiction. Always follow your healthcare provider's instructions to ensure safe use.

Is Mefenamic acid safe for the elderly?

Elderly patients are at a higher risk for serious side effects from Mefenamic acid, such as gastrointestinal bleeding and cardiovascular events. It's important to use the lowest effective dose for the shortest duration possible and to monitor for any adverse effects closely.

What are the most common side effects of Mefenamic acid?

A side effect is an unwanted effect caused by a medicine. Common side effects of Mefenamic acid include stomach pain, nausea, diarrhea, headache, and dizziness. These effects are often mild and may go away as your body adjusts. It's important to note that new symptoms can occur when starting any medicine and may not be related to the medicine itself. Always talk to your healthcare provider before stopping the medicine if you experience side effects.

Who should avoid taking Mefenamic acid?

Mefenamic acid carries risks of serious cardiovascular events and gastrointestinal bleeding. It is contraindicated in patients with a history of allergic reactions to NSAIDs, recent heart surgery, or active gastrointestinal bleeding. Always consult your doctor before use, especially if you have underlying health conditions.