The levothyroxine spectrum: bioequivalence and cost considerations
By Thomas M. Santella, BS and Albert I. Wertheimer, PhD, MBA
Published 1 August 2005 at FormularyWatch (online)
Abstract
Levothyroxine, a critical medication for millions of Americans, has had a long and turbulent history. In the face of tougher FDA regulations and especially its reclassification as a “new drug” in 1997, manufacturers have struggled to carve out their niche in an expansive market. The principal concern of physicians, patients, endocrinologists, manufacturers, and FDA is levothyroxine’ s relative bioequivalence. Even after FDA classified several products as bioequivalent, a single brand name product still holds most of the market share, despite the fact that it is more costly. Current issues surrounding levothyroxine include: controversy about research, the number and types of recalls, the lack of a single reference-listed drug for comparison, and conflicting claims about the bioequivalence of various formulations. (Formulary. 2005;40:258271.)
Early Treatment.
The First Synthetic.
Reclassification as a ‘New Drug’
Levothyroxine Problems.
Additional NDA Data.
Controversy Over Research.
A History of Recalls.
The Problem of Bioequivalence.
Bioequivalent Studies.
Levothyroxine Bioequivalence and FDA.
Current FDA Ratings.
Batch To Batch Concerns.
Influencing The Market.
Current Choices.
Conclusion.
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