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Published on: May 4, 2017
Including information on the therapeutic window in bioequivalence acceptance
Tom Jacobs1, Filip De Ridder, Sarah Rusch
1Interuniversity Institute for Biostatistics and Statistical Bioinformatics, Universiteit Hasselt, and Katholieke Universiteit Leuven, Belgium, Agoralaan 1, B3590 Diepenbeek, Belgium. tom.jacobs@uhasselt.be
Purpose:
A novel bioequivalence limit is proposed taking into account the therapeutic window.
Methods:
The therapeutic range is introduced as the ratios maximum tolerated dose/therapeutic dose (MTD/D) and the therapeutic dose/lowest effective dose. The performance of the new acceptance range was compared with the methods of Schuirmann and Karalis. The method was retrospectively applied to data of three drugs with a narrow therapeutic window (phenytoin, theophylline and digoxin).
Results:
Simulations and examples show that the resulting bioequivalence limits are (1) narrow for narrow-index drugs, (2) expanded for highly variable drugs with a wide therapeutic window and (3) similar to the classical limits for less variable drugs with a wide therapeutic range.
Conclusions:
The approach has the desirable property of resulting in a more narrow acceptance range for doses near the boundaries of the therapeutic window and a wider acceptance range for products with a broad therapeutic window.
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Therapeutic Index
