Bioequivalence and cost considerations levothyroxine
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.)
Hypothyroidism is the second most common endocrine disorder in theUnited States, second only to diabetes mellitus.1 Hypothyroidism is a chronic condition requiring lifetime compliance with hormone replacement therapy. Furthermore, because of the importance and difficulty of maintaining consistent hormone levels, patients have traditionally been tied to specific titrated doses. Because hypothyroidism is a condition in which the thyroid gland no longer produces an adequate supply of thyroid hormones (predominantlyT[SUB]4[/SUB]), a patient with untreated hypothyroidism may experience a variety of ill-effects, including weakness, skin changes, lethargy, slow speech, To date, there are several different treatment options for hypothyroidism,including Cytomel and supplemental T[SUB]3[/SUB], but the principal treatment for hypothyroidism remains levothyroxine, a synthetic form of T[SUB]4[/SUB].While the other treatments for hypothyroidism are certainly effective, they are beyond the scope of this article, as this article focuses on the most-prescribed treatment.