Re: How can 1/2 life be SAME for DIFF concentrations? » Janelle

Posted by JohnX2 on April 5, 2002, at 15:51:32

In reply to How can 1/2 life be SAME for DIFF concentrations?, posted by Janelle on April 5, 2002, at 14:45:06

> How can the number of half lives required to eliminate a drug (5-7 half lives and it's gone from body) be the SAME for DIFFERENT concentrations of the drug?
>
> Meaning, wouldn't a drug with a 100 mg/l concentration have fewer half-lives than one with say 350 mg/l concentration?
>
> I don't get this! Please help! Thanks!
Its not *exactly* the same, but its *really miniscule* after many half lifes relative to the base dose, if you use a really simplistic model of exponential 1/2 life decay.
I'll take your example into account:
time ----dose---------
t1 350.0 100.0
t2 175.0 50.0
t3 87.5 25.0
t4 43.7 12.5
t5 21.8 6.2
t6 10.9 3.1
t7 5.4 1.5
t8 2.7 0.8
John

Thread

Could someone explain HALF-LIFE w/ example! Janelle 4/4/02
...
Re: Relationship btw 1/2 life and onset of action? » Janelle IsoM 4/5/02
ELIZabeth: what does ^- mean? (nm) » Elizabeth Janelle 4/5/02
How can 1/2 life be SAME for DIFF concentrations? Janelle 4/5/02
FACHAD: what does GC/MS stand for? (nm) » fachad Janelle 4/5/02
ELIZABETH: what do AFAIk and HTH stand for?! (nm) » Elizabeth Janelle 4/5/02
FACHAD: you forgot my second question, here it is: » fachad Janelle 4/5/02
What does ^- mean in a computation? Janelle 4/5/02
Re: What does ^- mean in a computation? » Janelle JohnX2 4/5/02
What ^(-5) means » Janelle IsoM 4/5/02
AFAIk/as far as I'm concerned HTH/hope that helps (nm) » Janelle IsoM 4/5/02
GC/MS = Gas Chromatography / Mass Spectrometry » Janelle fachad 4/5/02
Re: How can 1/2 life be SAME for DIFF concentrations? » Janelle IsoM 4/5/02
Re: How can 1/2 life be SAME for DIFF concentrations? » Janelle JohnX2 4/5/02
2nd Question- It's All Relative » Janelle fachad 4/5/02
See Above Post » Janelle fachad 4/5/02
Re: FACHAD: 2 questions 4 U (1/2 lives revisited!) » Janelle Sunnely 4/5/02
ISO: thx, how do you raise to a negative number: Janelle 4/5/02
ISO: you are GREAT! But shouldn't it be AFAIc for: Janelle 4/5/02
Re: Relationship btw 1/2 life and onset of action? » Janelle Sunnely 4/5/02
No need 4 redirect, I understand! Thanks, JX2! (nm) » JohnX2 Janelle 4/5/02
ISO: Ack, I'm having trouble following that » IsoM Janelle 4/5/02
WHY is 2^-5 used to compute max # half-lives? Janelle 4/5/02
Re: WHY is 2^-5 used to compute max # half-lives? » Janelle JohnX2 4/5/02
I get the math now, but why 5, it seems arbitrary (nm) » JohnX2 Janelle 4/5/02
yes,5 is arbitrary, could just as well be 6 or 7.. (nm) » Janelle JohnX2 4/5/02
...
Re: Adam, I have no idea what you did! what is ''e''? 2sense 4/15/02

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