Mefenamic acid (Meftal) - Mechanism, precautions, side effects & uses

Summary

This video provides an in-depth overview of mefenamic acid, a non-steroidal anti-inflammatory drug (NSAID) commonly used for managing mild to moderate pain, particularly dysmenorrhea (menstrual pain). It explains its chemical structure, mechanism of action, and potential side effects, such as gastrointestinal issues, cardiovascular risks, and renal complications. The video highlights important precautions, emphasizing the careful use of mefenamic acid in adults and adolescents aged 14 and older. It concludes with recommendations for appropriate dosage and cautions regarding long-term use, aiming to ensure viewers understand both the benefits and risks of this medication.

Takeaways

• 😀 Mefenamic acid is a non-steroidal anti-inflammatory drug (NSAID) used to treat mild to moderate pain, especially menstrual pain (dysmenorrhea).
• 😀 It is an anthranilic acid derivative and works by inhibiting COX-1 and COX-2 enzymes, which are involved in pain and inflammation processes.
• 😀 Mefenamic acid is often combined with dicyclomine, an anticholinergic agent, to relieve both pain and spasms during menstruation.
• 😀 This drug is not recommended for children under 14 due to safety concerns, although it can be used in low doses to treat fever in children under medical supervision.
• 😀 The chemical structure of mefenamic acid includes a benzoic acid backbone and a 2,3-dimethyl aniline side chain.
• 😀 The drug works by blocking the production of prostaglandins, which are responsible for pain, inflammation, and other bodily processes.
• 😀 Mefenamic acid can cause gastrointestinal side effects, including ulcers, bleeding, and stomach pain, due to COX-1 inhibition.
• 😀 Long-term use of mefenamic acid can increase the risk of thrombotic events such as stroke and myocardial infarction, especially in individuals with pre-existing cardiovascular conditions.
• 😀 It can also cause renal issues, including reduced glomerular filtration rate (GFR) and hyperkalemia, particularly in patients with kidney problems.
• 😀 Common side effects include nausea, dizziness, skin rashes, fatigue, and headaches. Long-term use may lead to more serious issues like anemia or liver toxicity.
• 😀 Mefenamic acid should be used at the lowest effective dose to minimize risks, and the typical dosage is 500 mg initially, followed by 250 mg every 6 hours.

Q & A

What is Mefenamic Acid and what class of drug does it belong to?

Mefenamic Acid is a non-steroidal anti-inflammatory drug (NSAID) that belongs to the anthranilic acid derivative class, also known as mefanamic acid. It is primarily used to control mild to moderate pain, especially in conditions like dysmenorrhea (menstrual pain).

How does Mefenamic Acid help in controlling menstrual pain?

Mefenamic Acid works by inhibiting the synthesis of prostaglandins, which are chemicals that promote pain and inflammation. By reducing the levels of prostaglandins, it helps in controlling pain during menstruation or pre-menstrual pain.

Can Mefenamic Acid be used in children?

Mefenamic Acid is generally not recommended for children under 14 years due to safety concerns. However, it may be used in children at lower doses, such as 50 mg for fever, though this is an exception rather than the standard usage.

What is the chemical structure of Mefenamic Acid?

Mefenamic Acid is a benzoic acid derivative with a side chain of a methylated aniline ring. Its chemical name is 2,3-dimethyl-4-phenylaminobenzoic acid, which reflects the methyl groups attached to the aniline ring.

What are the potential gastrointestinal side effects of Mefenamic Acid?

Mefenamic Acid can increase the risk of gastrointestinal side effects, such as ulceration, perforation, and even gastrointestinal bleeding, especially at high doses. This is due to its inhibition of prostaglandins that help protect the stomach lining.

How does Mefenamic Acid affect cardiovascular health?

Mefenamic Acid, as a non-selective COX inhibitor, may increase the risk of cardiovascular events like stroke and myocardial infarction. This is due to the reduction of prostaglandin I2 (PGI2), which normally helps prevent platelet aggregation and promotes vasodilation.

What precautions should be taken when using Mefenamic Acid?

Mefenamic Acid should be used cautiously in patients with cardiovascular issues, kidney dysfunction, or a history of gastrointestinal problems. It should also be used at the lowest effective dose to minimize the risk of adverse events, including gastrointestinal bleeding and thrombotic complications.

How does Mefenamic Acid affect kidney function?

Mefenamic Acid can reduce kidney function by inhibiting the synthesis of protective prostaglandins (PGE2 and PGI2), which play a role in maintaining renal blood flow. This can lead to reduced glomerular filtration rate (GFR), causing fluid retention and potentially leading to hyperkalemia.

What are the common side effects of Mefenamic Acid?

Common side effects of Mefenamic Acid include abdominal pain, constipation, diarrhea, nausea, dizziness, headache, and skin reactions like rashes. Long-term use may lead to anemia due to gastrointestinal bleeding, fatigue, and jaundice.

What is the recommended dosage of Mefenamic Acid for adults and adolescents?

For adults and adolescents over 14 years of age, Mefenamic Acid is typically started at a dose of 500 mg, with subsequent doses of 250 mg every 6 hours, as needed. It should be used at the lowest effective dose to minimize risks of side effects, particularly for those with cardiovascular issues.