I’m assuming it has to do with making sure you get any straggler bacteria, but wouldn’t taking all the pills at once shock and awe the little buggers and force them to surrender?
In: Biology
I’m an infectious diseases pharmacist, so antibiotics and how they work is pretty much my bread and butter. There are actually lots of antibiotics that you can take just once a day, but usually the ones that you take multiple times a day tend to be ones, like beta lactams, that are time dependent rather than concentration dependent in their killing. Those are two broad categories of how antibiotics work, and for the multiple times a day ones, it’s about keeping a minimum level in the blood over a longer period of time, and adding more doesn’t actually kill more; above a certain level it doesn’t make a difference. There are actually certain antibiotics where we’ve moved from multiple times a day dosing to once a day dosing (aminoglycosides) but that was possible only because aminoglycosides are concentration dependent and therefore the higher doses can actually “shock and awe” as you put it and dosing that way actually lowers the toxicity that you see with aminoglycosides.
There are time dependent antibiotics that are dosed just once a day but those tend to have longer half lives, or are slower to leave the body so you don’t have to keep replenishing to keep it above that minimal level (ceftriaxone and ertapenem come to mind)
So if the abx is dosed multiple times a day, it’s a mix of, it’s probably time dependent killing and is processed by the body quickly(usually by the kidneys), and taking it all at once or just all doses just once a day doesn’t keep enough of it in your body long enough to kill the bacteria and you’ll have to go through another course.
Toxicity is secondary and not most of what is driving dosing decisions. Though if you try to take all your cephalexin at once I imagine the stomach upset would not be fun.
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