Gastrointestinal Malabsorption of Thyroxine

Escrito por Dra. Susana Scarone Imprimir


advance artilce Endo Societey


Gastrointestinal Malabsorption of Thyroxine
Camilla Virili, Alessandro Antonelli, Maria Giulia Santaguida, Salvatore Benvenga, Marco Centanni
Endocrine Reviews: Endocrine Society
Submitted: June 28, 2018 / Accepted: October 12, 2018 / First Online: November 23, 2018


Levothyroxine, a largely prescribed drug with a narrow therapeutic index, is often a lifelong treatment. The therapeutic efficacy of thyroxine may be marred by behavioral, pharmacologic and pathologic issues acting as interfering factors. Despite a continuous search for an optimal thyroxine treatment, a significant number of patients fail to show a complete chemical and/or clinical response to this reference dose of thyroxine. Gastrointestinal ADVANCE ARTICLE: Endocrine malabsorption of oral thyroxine represents an emerging cause of refractory hypothyroidism and may be more frequent than previously reputed.

In this review article we aimed at examining the pharmacologic features of thyroxine preparations and their linkage with the intestinal absorption of the hormone. We have stressed the major biochemical and pharmacologic characteristics of thyroxine and its interaction with the putative transporter at the intestinal level. We have examined the interfering role of nutrients, foods, and drugs on thyroxine absorption at gastric and intestinal level. The impact  of gastrointestinal disorders on thyroxine treatment efficacy has been also analyzed, in keeping with the site of action and the interfering mechanisms. Based on the evidence obtained from the literature, we also propose a schematic diagnostic workup for the most frequent and, often hidden, gastrointestinal diseases impairing thyroxine absorption. 


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Última actualización el 10 de Diciembre de 2018