PKBR
☆

Brazil,
2019-01-30 14:38
(969 d 13:01 ago)

(edited by mittyri on 2019-01-30 16:28)
Posting: # 19829
Views: 1,779

## PK/PD Index [PK / PD]

Dear all,

The PK / PD indexes are already well discussed in the literature, although they still present divergent points about the best index to be used for a given antimicrobial.

When we use the fAUC0-24 / MIC index, we have the concentration determined for 24 hours in single dose studies. But when we use only multi-dose antimicrobial in clinical practice, for example, every 6 or 8 or 12 hours, how can we evaluate this index if it mentions 0-24? Or should we do the collection experiment for 24 hours, even if this interval in no way represented sufficient exposure in the clinic? How can we evaluate this Pk/PD index for multiple dosing with intervals shorter than 24/24 hr? I'm confused. Could someone clarify this?

Thank you very much.

Edit: Category changed; see also this post #1. [Mittyri]
Please verify that category is right before posting!
mittyri
★★

Russia,
2019-01-31 23:12
(968 d 04:26 ago)

(edited by mittyri on 2019-01-31 23:40)
@ PKBR
Posting: # 19835
Views: 1,515

## fAUC0-24 / MIC index

Hi,

I'm not involved with antimicrobial stuff, but from my PK/PD understanding if the steady state is reached, the AUC won't change over different dose intervals (except of course some interoccasion variability).
So if for dose interval 8h you propose that AUCss0-8 equals to AUCss8-16, you can just multiply it to get an average value:
AUCss0-24 = AUCss0-8 * 3

Assumptions are:
- steady state
- no autoinduction or other time-varying parameters

Kind regards,
Mittyri
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