Mefenamic acid (Ponstan Forte) has a half life of 2 hours.

Naproxen has a half life of 12 to 17 hours.

Both are anti inflammatory drugs of apparently similar nature but could someone please explain the difference in half life?

Thank you

Mike

Absorbtion and breakdown are enzymatic reactions in the liver, "similar" is not good enough for many enzymes in reaction energy or speed. I would bet different enzyme pathways on breakdown.

Hi Mike!

Great question! The half-life of a drug refers to the time it takes for the concentration of the drug in the body to reduce by half. In the case of Mefenamic Acid (Ponstan Forte) with a half-life of 2 hours, it means that it takes approximately 2 hours for the concentration of the drug in the body to decrease by 50%.

On the other hand, Naproxen has a half-life ranging from 12 to 17 hours. This means that it takes much longer for the concentration of Naproxen in the body to decrease by half when compared to Mefenamic Acid.

The main difference in half-life between these two drugs is likely due to their chemical structures and the way they are metabolized and eliminated from the body.

It's important to note that the half-life of a drug can have implications for dosing frequency and overall drug effectiveness. A shorter half-life, like in the case of Mefenamic Acid, may require more frequent dosing to maintain therapeutic levels in the body. Conversely, a longer half-life, like in Naproxen, may necessitate less frequent dosing.

Ultimately, the half-life of a drug is one of many factors considered by healthcare professionals when determining the appropriate dosage and frequency for a patient.

I hope this explanation helps clarify the difference in half-lives between Mefenamic Acid and Naproxen! Let me know if you have any further questions.