Bioequivalence and Bioavailability Forum

Median tmax [Regulatives / Guidelines]

posted by Helmut  – Vienna, Austria, 2013-02-19 18:49 (4875 d 07:26 ago) – Posting: # 10063
Views: 11,197

Hi John,

are you are collector of ambiguities in guidances?

❝ For subjects who experience emesis post dose. The guideline stated emesis within 2x median Tmax. Can one use mean Tmax instead if the median value is not available?

Let’s see the wording:

Data deletion due to vomiting:

• We recommend that data from subjects who experience emesis during the course of a BE study for immediate-release products be deleted from statistical analysis if vomiting occurs at or before 2 times median Tmax. […]

So what’s “median t_max”? IMHO, there are two interpretations possible:

1. \(\small{\widetilde{t_\text{max}}}\) as stated in the RLD’s label. If have never seen it – only the bloody arithmetic mean \(\small{\overline{t_\text{max}}}\). In most cases the label gives a verbatim statement about the time of the maximum concentrations. In most NDAs only the mean is given.
   In European SmPCs and/or EPARs you find the \(\small{\widetilde{t_\text{max}}}\) sometimes.
   
2. The of t_max-values after the reference in the study – without the subject who vomited.

In my protocols I use #1 (if the median is known) or #2 otherwise. I don’t use (bad stat’s).

—
Dif-tor heh smusma 🖖🏼 Довге життя Україна! 
Helmut Schütz


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Science Quotes

Complete thread:

• FDA dropout guideline for Emesis jag009 2013-02-19 16:16 
  • Median tmaxHelmut 2013-02-19 17:49
    • Median tmax jag009 2013-02-19 19:49
      • Median tmax Helmut 2013-02-19 20:28
        • Median tmax jag009 2013-02-19 21:18
          • Intellectual horsepower Helmut 2013-02-19 21:49
            • Intellectual horsepower jag009 2013-02-19 22:45
            • Intellectual horsepower jag009 2013-02-20 16:12
              • Intellectual horsepower Helmut 2013-02-20 17:03
                • Intellectual horsepower jag009 2013-02-20 22:05
        • Median tmax luvblooms 2013-02-20 05:03
          • Sorry for the overgeneralization Helmut 2013-02-20 16:54
            • overgeneralization ???? luvblooms 2013-02-21 05:23
              • overgeneralization ???? Helmut 2013-02-21 12:17
              • overgeneralization ???? jag009 2013-02-21 16:55
    • Median tmax intuitivepharma 2013-02-28 13:05
      • Median tmax from pilot studies Helmut 2013-02-28 14:02