How do Claritin and other 24 hour meds work for 24 hours?

I guess the title asks it all!


In my experience, Claritin only works about 18 hours

It is some manufacturing processing gimmick call “Time Release.”
18 vs. 24 hours may be due to a particular individuals body chemistry with relation to the timed coating on the medication particles.

I don’t know if that’s true in the case of Claritin. The pills don’t appear to be the time-release capsules I’m used to; they look like any other chalky tablet.

What matters is the rate at which the medication is metabolized. That rate varies from drug to drug, and chemical to chemical. There’s no preset length of time that chemicals take to work their way out of your body - if whatever metabolic process removes Claritin from your bloodstream is slow, then it will last for a longer period of time in the body.

One of the prescriptions I’m taking is a daily dose. While plowing through the volume of small print on the product sheet (yeah, I do actually read those things) I noticed it said that the active ingredient had a half-life of 28 hours. Since it’s not radioactive, I guess that has something to do with the metabolization rate.

Excalibre has it right. Claritin has about an 11 hour halflife. Meaning that 24 hours after dosing, there’s still about a quarter of the original dose in the system.

And “timed release” is no gimmick. It’s very helpful for many circumstances.

In time release medications, the pill contains thousands of tiny balls of the actual medicine. The coatings on these individual balls vary, so that all of the dose isn’t released at the same time. The balls with the thinnest coating are used up ealier than the ones with thicker coatings.

There is a time-release version of Ritalin (I can’t think of the name right now) that lasts twelve hours. Half of the capsule is a small sponge. As the sponge absorbs digestive fluids, it expands, pushing the medicine out the other end. The empty capsule and sponge are expelled from the body in the usual way.

The time release version is called Concerta.

Claritin-24 contains 10 mg of loratidine; Claritin-12 contains 5 mg. That’s the entire difference.