C Oliver1, M Grino2, P Moatti Vacher-Coponat3, I Morange4, F Retornaz5. 1. Département de médecine gériatrique, centre gériatrique départemental, 176, avenue de Montolivet, 13012 Marseille, France; Institut Silvermed, 176, avenue de Montolivet, 13012 Marseille, France. Electronic address: charles.oliver30@orange.fr. 2. Institut Silvermed, 176, avenue de Montolivet, 13012 Marseille, France. 3. Clinique Saint-Laurent, Route nationale 96, 13360 Roquevaire, France. 4. Service d'endocrinologie, diabète et maladies métaboliques, 147, boulevard Baille, 13385 Marseille cedex 05, France. 5. Département de médecine gériatrique, centre gériatrique départemental, 176, avenue de Montolivet, 13012 Marseille, France; Institut Silvermed, 176, avenue de Montolivet, 13012 Marseille, France; Département de santé publique, EA3279 Aix-Marseille université, faculté de médecine, 27, boulevard Jean-Moulin, 13385 Marseille cedex 05, France; Département de médecine interne, hôpital européen, 6, rue Désirée-Clary, 13003 Marseille, France.
Abstract
INTRODUCTION: The non-adherence to substitutive treatment by L-thyroxine is the main cause of the discordance between high thyrotropin values and high doses of the drug. OBSERVATION: In a 36-year-old patient with post-surgery hypothyroidism, thyrotropin values ranged between 100 and 400 mUI/L, although daily replacement therapy included 300 μg of L-thyroxine and 75 μg of L-triiodothyronine. The oral loading test with L-thyroxine was normal and thyrotropin serum level returned to normal values under weekly oral administration of 1000 μg L-thyroxine. CONCLUSION: The strategy of non-adherence treatment in hypothyroidism is well defined with oral testing of L-thyroxine, followed by oral or parenteral weekly administration of the drug. The L-thyroxine oral test is the gold standard for diagnosis after eliminating of the other conventional causes: drug interactions or digestive malabsorption. L-thyroxine treatment should be discussed on a case-by-case basis, either daily under surveillance or once weekly oral or parenteral high dose.
INTRODUCTION: The non-adherence to substitutive treatment by L-thyroxine is the main cause of the discordance between high thyrotropin values and high doses of the drug. OBSERVATION: In a 36-year-old patient with post-surgery hypothyroidism, thyrotropin values ranged between 100 and 400 mUI/L, although daily replacement therapy included 300 μg of L-thyroxine and 75 μg of L-triiodothyronine. The oral loading test with L-thyroxine was normal and thyrotropin serum level returned to normal values under weekly oral administration of 1000 μg L-thyroxine. CONCLUSION: The strategy of non-adherence treatment in hypothyroidism is well defined with oral testing of L-thyroxine, followed by oral or parenteral weekly administration of the drug. The L-thyroxine oral test is the gold standard for diagnosis after eliminating of the other conventional causes: drug interactions or digestive malabsorption. L-thyroxine treatment should be discussed on a case-by-case basis, either daily under surveillance or once weekly oral or parenteral high dose.