Comparison of Levothyroxine Bioequivalence Between Products

• Main Author: Bersbach, Brian
• Other Authors: Slack, Marion
• Language: en_US
• Published: The University of Arizona. 2006
• Subjects: Hypothyroidism; Bioequivalence; Levothyroxine
• Online Access: http://hdl.handle.net/10150/624663; http://arizona.openrepository.com/arizona/handle/10150/624663

Class of 2006 Abstract === Background: Approximately 2% of the population has hypothyroidism, and are treated with a levothyroxine product. Unlike other medications, levothyroxine products have not been considered substitutable due to their narrow therapeutic window. Objectives: To compare the bioequivalence study findings from studies conducted by the manufacturer of Synthroid to those conducted by other investigators. Methods: Studies comparing levothyroxine product bioequivalence were found and divided according to time period, study design, and major funding party. Results: Ten studies excluded due to a change in Synthroid formulation. Six steady state studies and 3 single dose studies were left. Conclusions: Although data suggests bioequivalence between all studied levothyroxine products, there was not enough data to make a conclusion.