Aisha.ma
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United Arab Emirates,
2019-10-07 07:46

Posting: # 20672
Views: 324
 

 how to get t50%GIR-AUC(0-8h) in winnolin? [Software]

Dear all,
I am a biostatistician, and I have a project about insulin glargine. The parameter t50%GIR-AUC(0-8h) will be analysed, but I don't know how to get this parameter. Can I get it by WinNolin software and which parameter in WinNonlin will be? :confused:


Edit: Category changed; see also this post #1[Helmut]
Helmut
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Vienna, Austria,
2019-10-07 09:52

@ Aisha.ma
Posting: # 20673
Views: 298
 

 POT-50

Salam Aisha,

t50% (aka HVD – Half Value Duration, POT-50 – Peak Occupancy Time 50%) is not one of the PK metrics implemented in Phoenix WinNonlin.
  1. If your last sample was scheduled at 8 hours, follow the procedure described in this post.
  2. If you sampled longer, set up a data wizard / filter and include only time points ≤8 h and proceed with #1.

Cheers,
Helmut Schütz
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Aisha.ma
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United Arab Emirates,
2019-10-07 16:12

@ Helmut
Posting: # 20675
Views: 266
 

 POT-50

W.salam Helmut,
Thank you very much. Now I know how to get t50% Cmax via Phoenix WinNonlin. But I want to know t50% AUC(0-8h) (time to 50% of AUC, and my last sample was scheduled at 8 hours). So next what should I do if I know HVD?
I hope you help me again.:confused: Thank you so much.
Helmut
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Vienna, Austria,
2019-10-07 16:58

@ Aisha.ma
Posting: # 20676
Views: 261
 

 AUC-apical?

Hi Ashima,

BTW, are you referring to this guideline?

» But I want to know t50% AUC(0-8h) (time to 50% of AUC, and my last sample was scheduled at 8 hours).

Just to clarify: Are you interested in the yellow area?

[image]


Doesn’t look like your GIR cause that’s a PK profile but you get the idea. IIRC, this was called AUCapical by the “Two Lászlos” (Endrényi and Tóthfalusi). Have to dig it out.

Or this one?

[image]


» So next what should I do if I know HVD?

Both are not easy to calculate because HVD is the difference between the two intersections times which you don’t get in Phoenix. I suggest to register at Certara’s forum and post an example project containing the data of one subject.

Ideas:
  • Modify one of the R-scripts of this thread and call them from Phoenix.
  • Preliminary NCA (where we calculated 50%Cmax and 75%Cmax) > Final Parameters Pivoted > Data Wizard > Exclude Cmax_75
    Custom Function: New Column Name: Baseline, Formula: 0
    Properties: Cmax > Max_Response, Cmax_2 > Threshold
    Rename the Data Wizard to PD limits
    Set up another NCA-object > Options > Model Type Drug Effect (220)
    Therapeutic Response > Drag/drop the Results of PD limits (the mapping should be recognized)
    When you execute the NCA-Object you get
    AUC_Above_T
    AUC_Below_T
    AUC_Net_T

    I have to figure out which is what (in my example the last was negative).

Cheers,
Helmut Schütz
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Aisha.ma
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United Arab Emirates,
2019-10-07 18:43

@ Helmut
Posting: # 20677
Views: 243
 

 AUC-apical?

Hi Helmut,

» BTW, are you referring to this guideline?

Maybe the sponsor had consult this guideline before designing the study . Gir is the glucose-infusion rate.

» Just to clarify: Are you interested in the yellow area?
»

[image]


» Doesn’t look like your GIR cause that’s a PK profile but you get the idea. IIRC, this was called AUCapical by the “Two Lászlos” (Endrényi and Tóthfalusi). Have to dig it out.

I need to know time to 50% of GIR-AUC0-8. At the begining, I think that I can use summary table from Phoenix resluts and the function of AUC to get this time, but I am not sure whether this idea is right.
I have search many meterials about glucose-infsion study, this parameter is the secondary end. So it is a common parameter in glucose-infsion study, but I can not find the calculating mathod.:-(
Helmut
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Vienna, Austria,
2019-10-07 18:54

@ Aisha.ma
Posting: # 20678
Views: 235
 

 Define your terms!

Hi Aisha,

» I need to know time to 50% of GIR-AUC0-8.

That’s not my field. If the sponsor is so clever to demand a certain metric, ask what is exactly meant.

» At the begining, I think that I can use summary table from Phoenix resluts and the function of AUC to get this time, but I am not sure whether this idea is right.

No, this will not work.

» So it is a common parameter in glucose-infsion study, but I can not find the calculating mathod.

Fantastic. Keep searching. Once you know how it is defined, we can try to come up with a calculation method. Not before. Sorry.

Cheers,
Helmut Schütz
[image]

The quality of responses received is directly proportional to the quality of the question asked. ☼
Science Quotes
Aisha.ma
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United Arab Emirates,
2019-10-07 19:02

@ Helmut
Posting: # 20679
Views: 234
 

 Define your terms!

Hi Helmut,
Thank you so much. You have give me many useful information. I will search continue and I hope other experts in this forum also can help me.
nobody
nothing

2019-10-08 10:51

@ Aisha.ma
Posting: # 20681
Views: 198
 

 Define your terms!


Kindest regards, nobody
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