What does "half life" of a med mean....

I havent posted on here in quiite some time and have been keeping my anxiety pretty controlled but today I feel on the edge of panic. I have a nasty sinus infection and both my ears are infected and heavily clogged. The Dr gave me antibiotic (amox) and singulair to take along with Clariton D. I took a 5mg dose of the Singulair but have now read a listing of side effects a mile long. My hands and feet sweaty and I am on edge. I should have read before I took the pill bc now I am worse than I was before. I cant find how long it stays in your system but I do see half life is 2.7-5.5 hrs. Does anyone know what "half life" means...and would that mean in 5.4-11hrs it will no longer be effective?
I have terrible healthy anxiety especially when it comes to taking any new medicines I have never taken. I am hyper sensitive to a lot of meds & reading these condridictions makes me even more nervous.
Thanks for taking the time to read this.

[cj29]

Half life basically means how long it takes for half of the drug to be eliminated from your body/bloodstream.  

Also, remember any medication you take will have a list of side effects a mile long.  If you search the side effects of any pill on the internet of course it will scare the you know what out of you.  For example, if I looked up the potential side effects of the Motrin I took yesterday, I would probably never take it again.  Of course there are risks to anything we put into our body, but your doctor compares the risks vs. benefits of the drug when prescribing it to you.

Just make sure your doctor knows the medications you are on and another great resource in my opinion, is your pharmacist that fills your prescription.  In my experience they sometimes are much more patient and willing to talk to you about your concerns....keep us posted!

[greenlydia]

The concept of half-life is best understood by an example. Morphine provides a good illustration. The half-life of morphine is approximately 3 hours. By definition, this means that body stores of morphine will decrease by 50% every 3 hours.....regardless of how much morphine is in the body. If there is 50mg of morphine in the body, 25mg (50%) will be lost in 3 hours; if there is only 2mg of morphine in the body, only 1mg (50%) will be lost in 3 hours. Note that in both cases, morphine levels drop by 50% during an interval of one half-life. (3 hours)
Because I am not a pharmacist, when the Singulair bottle says the half-life is 2.7-5.5 hours, I don't have the knowledge to figure out why there is such a discrepency in the half-life. But the way I see it is that between every 2.7 hours to 5.5 hours, 50% of the amount of Singulair in your body will be eliminated. If you took a 5mg dose of Singulair, within the time frames they gave, you will only have 2.5mg left in your body. 2.7-5.5 hours later, you will have 50% of THAT amount left in your body.This 50% reduction will continue until all of the medication is out of your system.
I totally suck at math but maybe YOU'RE an Einstein and can figure out, from this equation, exactly when the last of the Singulair will leave your body. If we're both lousy at math, and you really want to know exactly when the last of this will be gone from your body, call your local pharmacist, who paid a gob of money for his education, and ask him to calculate this out for you.
You can also talk to him about your reactions, which he will be far more familar with than me.
I do know you'll be fine, it may just take a couple hours. Try to relax, drink lots of water which will help eliminate this from your body.
Peace
Greenlydia