Talk:Effective half-life

Delete.

Partially redundant wth Biological half-life and partially incorrect. Jclerman Jclerman 00:35, 12 January 2007 (UTC)

More than half of the article is incorrect. Please delete the whole thing. Jclerman (talk) 06:30, 19 September 2008 (UTC)

Definition

This is not redundant with Biological half-life. Biological half-life is, as it says here, one component of effective half-life. I think the problem is that the first paragraph defines "effective half-life" as the sum of all elimination mechanisms, and biological half-life is also defined as the sum of all elimination mechanisms. The difference, not clarified here, is that in the former, "elimination" is taken to include all the elimination mechanisms of biological half-life, plus additional mechanisms that reduce the substance's effectiveness--in the radionucleotide example, radioactive decay.

Another problem is how this relates to the use of "effective half-life" for indirect drugs like warfarin. Warfarin inhibits the production of coagulation factors, so its effect initially rises over time rather than decaying with time, as those factors are cleared from the blood. The "effective half-life of warfarin" seems to mean the time after which half of those coagulation factors have been cleared from the blood, rather than measuring the half-life of warfarin itself. In that case "effective half-life" is intended to mean the half-life of the inhibited factors--but this is not a true half-life, since the curve describing their concentration over time will not be an exponential decay. Philgoetz (talk) 02:41, 12 December 2018 (UTC)