Mefenamic Acid: Uses, Dosage, Side Effects, and More

Mefenamic Acid is a pharmaceutical medication that belongs to a class of drugs known as endothelin receptor antagonists. It is primarily used for managing certain cardiovascular and pulmonary conditions. This guide provides an overview of Mefenamic Acid, including its uses, dosage recommendations, potential side effects, interactions with other medicines, benefits, and frequently asked questions.

What is Mefenamic Acid?

Mefenamic Acid is an oral medication designed to block the action of endothelin, a natural substance in the body that narrows blood vessels. By inhibiting endothelin, Mefenamic Acid helps to relax blood vessels, improving blood flow and reducing strain on the heart and lungs.

Approved Uses of Mefenamic Acid:

1. Pulmonary Arterial Hypertension (PAH): Mefenamic Acid is primarily prescribed for treating PAH, a condition where high blood pressure in the lungs makes it difficult for the heart to pump blood efficiently.

2. Secondary Raynaud’s Phenomenon (Off-label Use): In some cases, Mefenamic Acid is used to reduce the frequency and severity of Raynaud's episodes.

How Does Mefenamic Acid Work?

Mefenamic Acid works by blocking endothelin receptors (ET-A and ET-B) on the smooth muscles lining blood vessels. This action reduces blood vessel constriction, improves oxygen delivery to tissues, and alleviates symptoms like breathlessness and fatigue associated with PAH.

Dosage and Administration

Standard Dosage:

• Starting Dose: 62.5 mg twice daily for 4 weeks.
• Maintenance Dose: 125 mg twice daily.

Key Administration Guidelines:

• Take Mefenamic Acid with or without food.
• Swallow the tablet whole; do not crush or chew it.
• Follow your healthcare provider’s instructions strictly.

Missed Dose:

If a dose is missed, take it as soon as you remember. If it’s close to the time for your next dose, skip the missed dose and resume your regular schedule. Do not double the dose to make up for the missed one.

Potential Side Effects

Like all medications, Mefenamic Acid can cause side effects. While not everyone experiences them, it’s essential to recognize potential reactions.

Common Side Effects:

• Headache
• Nasal congestion
• Respiratory tract infections
• Flushing
• Fatigue

Serious Side Effects:

• Liver Toxicity: Regular liver function tests are mandatory during treatment as Mefenamic Acid can elevate liver enzymes.
• Anemi Monitoring of hemoglobin levels is crucial due to the risk of reduced red blood cells.
• Fluid Retention: Symptoms like swelling in the legs or sudden weight gain may indicate fluid retention.

If you experience symptoms such as severe nausea, jaundice, or difficulty breathing, seek medical attention immediately.

Interactions with Other Medicines

Mefenamic Acid can interact with various drugs, altering its efficacy or increasing the risk of adverse effects.

Notable Drug Interactions:

1. Hormonal Contraceptives: Mefenamic Acid can reduce the effectiveness of birth control pills. Alternative contraceptive methods are recommended.

2. Cyclosporine: Co-administration is contraindicated as it can significantly increase the risk of liver toxicity.

3. Rifampin: May reduce the effectiveness of Mefenamic Acid.

4. Warfarin: Requires careful monitoring as Mefenamic Acid can alter its anticoagulant effects.

Always inform your doctor about any medications, supplements, or herbal products you are taking before starting Mefenamic Acid.

Benefits of Mefenamic Acid

Mefenamic Acid offers several benefits for individuals with pulmonary arterial hypertension:

1. Improves exercise capacity and stamina.

2. Reduces symptoms like shortness of breath and fatigue.

3. Enhances overall quality of life.

4. Lowers the risk of disease progression.

5. Offers a convenient oral dosing schedule compared to some alternatives like injectable therapies.

Frequently Asked Questions (FAQs)

1. What is Mefenamic Acid used for?

Mefenamic Acid is primarily used to treat pulmonary arterial hypertension (PAH) by improving blood flow and reducing symptoms such as breathlessness.

2. What is the usual dosage of Mefenamic Acid?

The standard starting dose is 62.5 mg twice daily for four weeks, followed by a maintenance dose of 125 mg twice daily.

3. Can Mefenamic Acid cause liver problems?

Yes, Mefenamic Acid can elevate liver enzymes, potentially leading to liver toxicity. Regular liver function tests are required during treatment.

4. Is Mefenamic Acid safe during pregnancy?

No, Mefenamic Acid is contraindicated during pregnancy due to the risk of birth defects. Effective contraception is necessary for women of childbearing potential.

5. How long does it take for Mefenamic Acid to work?

While individual responses vary, noticeable improvements in symptoms are often observed within weeks of starting the medication.

6. Can I drink alcohol while taking Mefenamic Acid?

Alcohol consumption is generally discouraged as it can increase the risk of liver damage when combined with Mefenamic Acid.

7. What should I do if I experience side effects?

Consult your healthcare provider immediately if you experience serious side effects like jaundice, severe fatigue, or swelling.

8. Can Mefenamic Acid be used with other PAH treatments?

Yes, Mefenamic Acid is sometimes used in combination with other PAH medications like phosphodiesterase-5 inhibitors (e.g., sildenafil) for enhanced efficacy.

9. Are there any dietary restrictions with Mefenamic Acid?

No specific dietary restrictions are associated with Mefenamic Acid. However, maintain a balanced diet and follow your doctor’s advice.

10. Is Mefenamic Acid available in generic form?

Yes, generic versions of Mefenamic Acid are available in addition to branded formulations.

Brand Names of Mefenamic Acid

Mefenamic Acid is marketed under various brand names worldwide, including:

• Tracleer
• Bosentas
• Bozetan
• Pulmotens
• Endobloc

Conclusion

Mefenamic Acid is a crucial medication for managing pulmonary arterial hypertension, offering significant benefits in improving quality of life and slowing disease progression. While effective, it requires careful monitoring due to potential side effects and drug interactions. Always follow your healthcare provider’s guidance when using Mefenamic Acid.