Bioequivalence and Bioavailability Forum

Religious debate [Regulatives / Guidelines]

posted by Helmut  – Vienna, Austria, 2016-02-12 18:04 (3259 d 18:50 ago) – Posting: # 15985
Views: 19,809

Hi nobody,

❝ ❝ Ahem. What to you mean by nonsense – apart from the word “terminal”?

❝

❝ I don't like this parameter, it's often used/compared in senseless ways. Clearance, volume, f is closer to the clinical reality. But doctors (and many others) can handle "times" (hours), but not "liters per hour" (but AUC divided by dose they find highly intuitive, which is 1/clearance ... )

On David Bourne’s PKPD-list we have the annual religious debate (aka chicken vs. egg). The thread “A question of clearance” (part 1: 2009, part 2: 2010) set the record since 1995 (!) with an amazing 152 posts. I don’t belong to any of the churches (parameterization of models in terms of rate constants or clearances).
Both are mechanistic and purely empirical. Volume(s) of distribution and clearance(s) are theoretical constructs as are rate constants. Is the body a well-stirred beaker? C’mon! This is the fundamental (but delusionary) world of both churches. I can’t agree that any of the parameters is “closer to the clinical reality”. There is one exception: Hemodialysis, where the volume of distribution chances. This is the only case where I tend to lean towards the V & CL-church. In all other cases and when it comes to NCA [sic] I’m happy with both.
What I definitely don’t like is that PK software in evaluating data of an extravascular dose spit out CL/ƒ, V/ƒ, etc. Since ƒ is unknown, this kind of “information” is meaningless. When I review manuscripts I have a polite boilerplate for that.

—
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:

• Baseline correction vs non-baseline cor­rection jag009 2015-09-15 20:29 [Regulatives / Guidelines] 
  • Baseline correction vs non-baseline correction Lucas 2015-09-16 14:16
    • Baseline correction vs non-baseline correction Relaxation 2015-09-18 10:25
  • Baseline correction or supra-thera­peu­tic dose Helmut 2015-09-16 15:16
    • Baseline correction or supra-thera­peu­tic dose Ohlbe 2015-09-16 17:55
      • Baseline profile prior to each period? Helmut 2015-09-16 18:15
      • Baseline correction examples Helmut 2015-09-17 15:44
        • Baseline correction examples Lucas 2015-09-18 14:19
          • Baseline correction examples Helmut 2015-09-18 17:28
            • Baseline correction examples Mauricio Sampaio 2016-02-07 03:05
              • Baseline correction examples Lucas 2016-02-10 11:48
                • Postmenopausal women Helmut 2016-02-10 12:26
                • Baseline correction examples Mauricio Sampaio 2016-02-11 01:38
                • Baseline correction examples Dr_Dan 2016-02-11 09:22
                  • Postmenopausal women Mauricio Sampaio 2016-02-12 03:24
                    • Postmenopausal women Dr_Dan 2016-02-15 17:45
            • Baseline correction examples BEQool 2024-11-11 07:34
              • Baseline correction GeoMean and Median mittyri 2024-11-11 11:20
                • Geometric mean? Helmut 2024-11-11 14:53
                  • Geometric mean? BEQool 2024-11-14 08:19
                    • Geometric mean ≈ MLE of median Helmut 2024-11-14 09:54
                      • Geometric mean ≈ MLE of median Mahmoud 2024-11-15 11:26
                        • Bias? Helmut 2024-11-16 08:43
                          • Bias? Mahmoud 2024-11-16 11:12
      • Baseline; another example Helmut 2015-09-18 17:16
        • Baseline; another example nobody 2016-02-12 09:10
          • Baseline; another example Helmut 2016-02-12 13:37
            • Baseline; another example nobody 2016-02-12 14:08
              • Slowly going OT: BE study simulations Helmut 2016-02-12 15:47
                • Slowly going OT: BE study simulations nobody 2016-02-12 16:15
                  • Religious debateHelmut 2016-02-12 17:04
                    • Religious debate nobody 2016-02-12 17:26
                      • Religious debate ElMaestro 2016-02-13 12:53
                        • Religious debate nobody 2016-02-14 15:23
                • Slowly going OT: BE study simulations Ohlbe 2016-02-13 13:10
                  • Slowly going OT: BE study simulations Helmut 2016-02-13 15:02
                    • Slowly going OT: BE study simulations lizhao 2016-02-25 17:31
                      • Business as usual Helmut 2016-02-25 17:44
                        • Business as usual lizhao 2016-02-25 17:59