Bioequivalence and Bioavailability Forum

Kel or λz? [PK / PD]

posted by Helmut  – Vienna, Austria, 2014-12-28 14:56 (3837 d 16:08 ago) – Posting: # 14182
Views: 12,706

Hi Astea,

❝ Can you please give me some links where to find the information of how to calculate Kel for drugs with enterohepatic recycling?

If you are dealing with an oral dose it is practically impossible to claim enterohepatic recycling. A second peak may also be the result of transfer for the stomach to the duodenum, a food effect (increased hepatic blood flow), etc. Only if you see a second peak after an iv dose you have strong hints. Many models exist, and without an IV dose and sampling faeces PK parameters are not identifiable. No idea about the web. it. Standard PK textbooks contain examples.

❝ What part of the curve we should use for analysis?

The latest one. If you are talking about BA/BE we are only applying NCA (i.e., we are not dealing with PK models: \(\small{\lambda_\textrm{z}\neq k_\textrm{el}}\)). Only make sure that you have at least three samples in the log/linear decline and AUC_t covers ≥80% of AUC_∞.

—
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:

• enterohepatic recycling, how to calculate Kel? Astea 2014-12-28 12:40 
  • Kel or λz?Helmut 2014-12-28 13:56
    • Kel or λz? Astea 2014-12-28 14:42
      • Kel or λz? Helmut 2014-12-28 15:34
        • Kel or λz? Astea 2014-12-28 17:48
          • Kel or λz? mittyri 2014-12-28 20:25
            • Kel or λz? Astea 2014-12-28 21:21
          • Kel or λz? Helmut 2014-12-29 02:58
            • Kel or λz? Astea 2014-12-29 10:38
              • TOST Helmut 2014-12-29 14:14
                • PowerTOST d_labes 2014-12-31 13:41
    • Kel or λz? luvblooms 2014-12-29 05:51
      • Kel or λz? nobody 2014-12-29 21:54
        • Kel or λz? luvblooms 2014-12-30 05:25