Combined T4 and T3 Therapy—Back to the Drawing Board
- David S. Cooper, MD
- Author Affiliation: Division of Endocrinology, Sinai Hospital of Baltimore and the Johns Hopkins University School of Medicine, Baltimore, Md. Dr Cooper is Contributing Editor, JAMA.
Since this article does not have an abstract, we have provided the first 150 words of the full text.
Hormone replacement therapy" was originally reported by Murray, who in 1891 described the successful treatment of myxedema with injections of sheep thyroid extract.1 By 1898, therapy for this chronic, severely debilitating condition was hailed as "unparalleled by anything in the whole range of curative measures" by Osler.2 Seven decades later, desiccated thyroid was characterized by the standard thyroid textbook of the day as ". . . as perfect a form of therapy as any known to medicine. . . ."3 With the subsequent identification of thyroxine (T4) and triiodothyronine (T3) as the 2 major thyroid hormones, it was assumed that replacement therapies containing both compounds were more physiological than treatment with either alone. Thus, despite the availability of synthetic T4 in the early 1960s, the prescription of desiccated animal thyroid or synthetic combinations of T4 and T3 continued well into the 1970s. …
