BACKGROUND Untreated maternal hypothyroidism can have adverse effects on both the mother and fetus, but it can potentially be prevented by adequate levothyroxine replacement. This study was conducted to determine what percentage of hypothyroid pregnant women who were taking levothyroxine needed to adjust their medication dosage, and when and how much it should be increased. METHODS In this lo...

Thyroxine hormone has been recognised since the early part of the nineteenth century and levothyroxine has been available since the midnineteenth century as a replacement for deficient thyroid hormones. While levothyroxine remains the staple treatment for hypothyroidism even to this day, its optimal use can be challenging. As is often the case with older drugs, the pharmacokinetics of levothyro...

BACKGROUND Hypothyroidism can usually be treated effectively by oral levothyroxine supplementation. There are, however, some rare circumstances, when oral levothyroxine application is not sufficient, for example malabsorption, interactions with food or other medications, or various gastrointestinal diseases. CASE REPORT We present a 42 year old woman with refractory and severe symptomatic hyp...

Levothyroxine is one of the most commonly prescribed medications for the treatment of persons with hypothyroidism and the suppression of thyroid neoplasms.1 Most persons with hypothyroidism require lifelong therapy with levothyroxine. The absorption of levothyroxine after oral administration is about 80%.1 Certain drugs and dietary components2,3 can interfere with the bioavailability of levothy...

Methods We report a case of drug rash induced by levothyroxine and currently oral desensitization. A 31 year-old woman had been diagnosed as Hashimoto’s Thyroiditis. She was having levothyroxine for 9 years when she begun to present bilateral eyelids maculopapular rash. Blood exams and physical examination were normal except for the eyelids ́ rash. As she stopped using levothyroxine, the rash ha...

As in some patients with hypothyroidism, because of unknown reasons, large doses of levothyroxine are required to achieve a therapeutic endpoint, and preliminary observations have indicated that an hypoacidic gastric environment is associated with a reduction in levothyroxine bioavailability, and that co-administration of vitamin C might enhance absorption of certain drugs, we assessed whether ...

BACKGROUND Chronic supplementation can suppress the hypothalamic-pituitary-thyroid axis (HPTA) and make it difficult to assess thyroid function after withdrawal of levothyroxine. OBJECTIVES To determine whether the HPTA is suppressed after levothyroxine administration in euthyroid dogs and the time required for resolution of any suppression. ANIMALS Twenty-eight healthy euthyroid dogs. ME...

BACKGROUND Patients receiving the multikinase inhibitor sorafenib for locally recurrent or metastatic, progressive, differentiated thyroid carcinoma (DTC) refractory to radioactive iodine often receive concomitant levothyroxine for thyrotropin (TSH) suppression. In the Phase 3 DTC trial (DECISION), sorafenib exposure was approximately twofold higher than that observed in other cancers. This stu...

OBJECTIVE To determine the rate of exposure of pregnant women to levothyroxine and to assess changes in these rates before, during and after pregnancy. DESIGN Register-based cohort study. SETTING Danish nationwide registers. POPULATION All women having a live birth in Denmark between 1 January 1997 and 31 December 2010 (n = 912 342). METHODS All pregnant women in the study period were i...

Congenital hypothyroidism requires prompt treatment to prevent adverse health outcomes. Poor intestinal levothyroxine absorption can complicate management. We present a case of a term female newborn with necrotizing enterocolitis (NEC) requiring subtotal ileum resection. Congenital hypothyroidism was diagnosed by newborn screening. Treatment was complicated by intestinal malabsorption of levoth...