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RegisterAUC=f·D/CL [Study Assessment]
posted by Helmut 
– Vienna, Austria, 2018-02-08 11:28 (2410 d 09:07 ago) – Posting: # 18379
Views: 10,034
Hi sussu,
Exactly. The input function does not appear in the basic equation of PK (AUC=ƒ·D/CL). Since after an i.v. dose ƒ=1 (by definition) and the entire dose was administered, the AUC will be exactly the same regardless the input scheme.
Say you stopped after 15 minutes and administered the remaing dose after 29 minutes as a fast (one minute) bolus, it will look like this:
Note that the red line after tmax is above the blue one. With a t½ of 8 h the “missing” part before tmax will be outweighed in the elimination phase (speaking of AUC0–∞; the AUC0–2 will be lower, of course).
❝ I thought the AUC would be effect because I saw the the black area in the below picture. Now i know the AUC is only depend on the dose as you said.
❝ [image]
Exactly. The input function does not appear in the basic equation of PK (AUC=ƒ·D/CL). Since after an i.v. dose ƒ=1 (by definition) and the entire dose was administered, the AUC will be exactly the same regardless the input scheme.
Say you stopped after 15 minutes and administered the remaing dose after 29 minutes as a fast (one minute) bolus, it will look like this:
![[image]](img/uploaded/image490.png)
Note that the red line after tmax is above the blue one. With a t½ of 8 h the “missing” part before tmax will be outweighed in the elimination phase (speaking of AUC0–∞; the AUC0–2 will be lower, of course).
—
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Helmut Schütz
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Dif-tor heh smusma 🖖🏼 Довге життя Україна!
Helmut Schütz
The quality of responses received is directly proportional to the quality of the question asked. 🚮
Science Quotes
Complete thread:
- When the the infusion speed deviate from the protocol specified ssussu 2018-02-06 10:48 [Study Assessment]
![[Mix]](https://static.bebac.at/img/mix.png "open in Mix view")
- Different PK profile Helmut 2018-02-06 13:28
- Different PK profile ssussu 2018-02-07 02:50
- Different PK profile Helmut 2018-02-07 11:04
- Different PK profile ssussu 2018-02-07 11:42
- Suitable equipment? Helmut 2018-02-07 14:13
- Suitable equipment? ssussu 2018-02-08 04:07
- AUC=f·D/CLHelmut 2018-02-08 10:28
- AUC=f·D/CL ssussu 2018-02-08 11:21
- AUC=f·D/CL Helmut 2018-02-08 21:55
- AUC=f·D/CL ssussu 2018-02-09 00:31
- AUC=f·D/CL Helmut 2018-02-08 21:55
- AUC=f·D/CL ssussu 2018-02-08 11:21
- AUC=f·D/CLHelmut 2018-02-08 10:28
- Suitable equipment? ssussu 2018-02-08 04:07
- Suitable equipment? Helmut 2018-02-07 14:13
- Different PK profile ssussu 2018-02-07 11:42
- Different PK profile Helmut 2018-02-07 11:04
- Different PK profile ssussu 2018-02-07 02:50
- When the the infusion speed deviate from the protocol specified ElMaestro 2018-02-07 13:20
- When the the infusion speed deviate from the protocol specified ssussu 2018-02-08 04:23
- Different PK profile Helmut 2018-02-06 13:28
Ing. Helmut Schütz