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

Posted by IsoM on April 5, 2002, at 15:33:38

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

It's not simply the measurement of a drug but but how much is needed to work. If 500 mg of drug X has the proper effect then at 5-7 half-lives, what's left of it would have little effect on the body & not even be noticed.
On the other hand, if only 5 mg of drug Y is needed for effectiveness, then with just one half-life, concentration would be at 2.5 mg - much less than 15.625 mg of drug X (now at 5 half-lives) still it's not the amount left but how much is needed to cause an effect.
Think of the difference in how much salt as compared to sugar is needed in a cake to be good tasting as a comparison.

Thread

Could someone explain HALF-LIFE w/ example! Janelle 4/4/02
...
How Many Half-Lives Until it's Gone? » Janelle fachad 4/5/02
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
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Re: Adam, I have no idea what you did! what is ''e''? 2sense 4/15/02

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