scholarly journals Levothyroxine Therapy in Thyrodectomized Patients

2021 ◽  
Vol 11 ◽  
Author(s):  
Paolo Miccoli ◽  
Gabriele Materazzi ◽  
Leonardo Rossi
Keyword(s):  
Thyroid Hormone ◽  
Total Thyroidectomy ◽  
Dietary Habits ◽  
Hormone Replacement ◽  
Thyroid Function Test ◽  
Optimal Dose ◽  
Serum Levels ◽  
Primary Hypothyroidism ◽  
Oral Solution ◽  
Bile Acid Sequestrants

Administration of the optimal dose of levothyroxine (LT4) is crucial to restore euthyroidism after total thyroidectomy. An insufficient or excessive dosage may result in hypothyroidism or thyrotoxicosis, either one associated with a number of symptoms/complications. Most literature regarding the LT4 dosage deals with the treatment of primary hypothyroidism, whereas a limited number of studies handle the issue of thyroxin replacement after total thyroidectomy. A literature review was performed focusing on all papers dealing with this topic within the last 15 years. Papers that reported a scheme to calculate the proper LT4 dose were collected and compared to set up a review exploring limits and drawbacks of LT4 replacement therapy in the wide population of patients who had undergone thyroidectomy. Most of the methods for monitoring and adjusting thyroid hormone replacement after thyroidectomy for benign disease use LT4 at an empirical dose of approximately 1.6 μg/kg, with subsequent changes according to thyroid function test results and assessments of the patient’s symptoms. Approximately 75% of patients require a dose adjustment, suggesting that factors other than body weight play a role in the determination of the proper LT4 dose. Hence, several schemes are reported in the literature for the proper initial dose of LT4. An inadequate level of thyroid hormone levels in these patients can be due to several factors. The most common ones that lead to the necessity of LT4 dose adjustments include lack of compliance, changes in LT4 formulation, dosage errors, increased serum levels of T4-binding globulin, body mass changes, and dietary habits. Moreover, concomitant ingestion of calcium supplements, ferrous sulfate, proton-pump inhibitors, bile acid sequestrants, and sucralfate might influence LT4 absorption and/or metabolism. Furthermore, some gastrointestinal conditions and their treatments can contribute to suboptimal LT4 performance by altering gastric acidity and thereby reducing its bioavailability, particularly in the solid form. Beyond the classic tablet form, new formulations of LT4, such as a soft gel capsule and an oral solution, recently became available. The liquid formulation is supposed to overcome the food and beverages interference with absorption of LT4 tablets.

Twice-Weekly Dosing for Thyroxine Replacement in Elderly Patients with Primary Hypothyroidism

1994 ◽  
Vol 22 (5) ◽  
pp. 273-277 ◽  
Author(s):  
J Taylor ◽  
B O Williams ◽  
J Frater ◽  
D J Stott ◽  
J Connell
Keyword(s):  
Thyroid Hormone ◽  
Elderly Patients ◽  
Hormone Replacement ◽  
Systolic Time Intervals ◽  
Serum Levels ◽  
Primary Hypothyroidism ◽  
Time Intervals ◽  
Thyroxine Therapy ◽  
Total Triiodothyronine ◽  
Systolic Time

Seven female patients (mean age 86 years) with proven biochemical primary hypothyroidism were enrolled in a single-blind randomized crossover study, of standard daily versus twice-weekly thyroxine therapy, with each phase of one month's duration. The median daily dose of thyroxine was 100 μg (range 75 – 100 μg). Serum levels of thyroid hormones and thyrotrophin were very similar during twice-weekly thyroxine therapy to those during daily therapy and there were no statistically significant differences between trough and peak serum total triiodothyronine, free thyroxine, or thyrotrophin levels or systolic time intervals during twice-weekly thyroxine. Administration of thyroxine twice-weekly to elderly patients with primary hypothyroidism gives effective biochemical thyroid hormone replacement, with no evidence from the systolic time intervals of tissue thyrotoxicosis at expected peak thyroid hormone concentrations. Supervised twice-weekly thyroxine should be considered in patients with primary hypothyroidism who comply poorly with daily dosing.

scholarly journals Effect of Adequate Thyroid Hormone Replacement on the Hypothalamo-Pituitary-Gonadal Axis in Premenopausal Women with Primary Hypothyroidism

2019 ◽  
Vol 8 (3) ◽  
pp. 152-158
Author(s):  
Bharath Bachimanchi ◽  
Suresh Vaikkakara ◽  
Alok Sachan ◽  
Ganji Praveen Kumar ◽  
Ashok Venkatanarasu ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Hormone Replacement ◽  
Premenopausal Women ◽  
Primary Hypothyroidism ◽  
Thyroid Hormone Replacement

scholarly journals SAT-LB85 Use of Weekly Levothyroxine Regimen for Rapid Normalization of Thyroid Hormone Levels: A Case Report

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Jose Renato Martinez Escudero ◽  
Johnathan Kirupakaran ◽  
Alice Yau ◽  
Giovanna Rodriguez ◽  
Gul Bahtiyar
Keyword(s):  
Thyroid Hormone ◽  
Thyroid Function ◽  
Time Course ◽  
Sinus Bradycardia ◽  
Hormone Replacement ◽  
Tertiary Care ◽  
Thyroid Function Test ◽  
Tertiary Care Centre ◽  
Endocrine Society ◽  
Thyroid Hormone Replacement

Abstract Background: Hypothyroidism affects around 4.6% of the U.S. population1. Non-adherence with thyroid hormone replacement is one of the biggest challenges in treating hypothyroidism1. The half-life of T4 and T3 in hypothyroidism is about 7.5 and 1.4 days respectively2. A large dose once-weekly administration of levothyroxine (Lt4) is possible3, 4. Recent publications suggest that once-weekly Lt4 does not increase the risk of cardiovascular events and is well tolerated by most of patients4. Once weekly Lt4 produces similar results as daily Lt4 as evidenced by thyroid function tests3,4, and potentially improves patient compliance and satisfaction with the treatment4. Clinical Course: A 29-year-old female with a history of Hashimoto’s hypothyroidism, polycystic ovarian syndrome, depression, presented with irregular menses. Her symptoms included depression, fatigue, increased appetite. Her TSH was grossly elevated at 217 uIU/mL (0.27-4.20 uIU/mL). However upon re-visit, after increasing Lt4 to 100 mcg daily her TSH increased to 280 uIU/mL. She admitted to non-adherence with her daily Lt4 prescription. Physical exam was notable for sinus bradycardia and slow mentation, otherwise unremarkable. Blood count, basic metabolic panel and hemoglobin A1C were within normal limits. Liver function tests showed mild transaminitis, ALT 46 U/L (10-45 U/L). Lt4 was started at 875 mcg per week. At five weeks, her TSH was 6.31 uIU/mL and at seven weeks, the patient was euthyroid with a TSH of 2.53 uIU/mL. Her periods have since normalized. Conclusion: The current discourse on weekly dosing mainly focuses on its use for non-adherent patients. This case provides a clear time course also demonstrating rapid normalization of TSH using weekly dosing. Weekly Lt4 dosing as first-line therapy in noncompliant depressed patients with severe hypothyroidism should be considered. 1.Hepp, Z., Wyne, K., Manthena, S., Wang, S. and Gossain, V. (2018). Adherence to thyroid hormone replacement therapy: a retrospective, claims database analysis. Current Medical Research and Opinion, 34(9), pp.1673-1678.2.Colucci, P., Yue, C., Ducharme, M. and Benvenga, S. (2010). A Review of the Pharmacokinetics of Levothyroxine for the Treatment of Hypothyroidism. European Endocrinology, 9(1), p.40.3.Jayakumari, C., Nair, A., Puthiyaveettil Khadar, J., Das, D., Prasad, N., Jessy, S., Gopi, A. and Guruprasad, P. (2019). Efficacy and Safety of Once-Weekly Thyroxine for Thyroxine-Resistant Hypothyroidism. Journal of the Endocrine Society, 3(12), pp.2184-2193.4.Rajput, R. and Pathak, V. (2017). The Effect of Daily versus Weekly Levothyroxine Replacement on Thyroid Function Test in Hypothyroid Patients at a Tertiary Care Centre in Haryana. European Thyroid Journal, 6(5), pp.250-254.

scholarly journals Effects of thyroid hormones on thermogenesis and energy partitioning

2018 ◽  
Vol 60 (3) ◽  
pp. R157-R170 ◽  
Author(s):  
K Alexander Iwen ◽  
Rebecca Oelkrug ◽  
Georg Brabant
Keyword(s):  
Thyroid Hormone ◽  
Thyroid Hormones ◽  
Cold Exposure ◽  
Energy Homeostasis ◽  
Current Knowledge ◽  
Hormone Replacement ◽  
Primary Hypothyroidism ◽  
The Central Nervous System ◽  
Primary Hyperthyroidism ◽  
Peripheral Cells

Thyroid hormones (TH) are of central importance for thermogenesis, energy homeostasis and metabolism. Here, we will discuss these aspects by focussing on the physiological aspects of TH-dependent regulation in response to cold exposure and fasting, which will be compared to alterations in primary hyperthyroidism and hypothyroidism. In particular, we will summarise current knowledge on regional thyroid hormone status in the central nervous system (CNS) and in peripheral cells. In contrast to hyperthyroidism and hypothyroidism, where parallel changes are observed, local alterations in the CNS differ to peripheral compartments when induced by cold exposure or fasting. Cold exposure is associated with low hypothalamic TH concentrations but increased TH levels in the periphery. Fasting results in a reversed TH pattern. Primary hypothyroidism and hyperthyroidism disrupt these fine-tuned adaptive mechanisms and both, the hypothalamus and the periphery, will have the same TH status. These important mechanisms need to be considered when discussing thyroid hormone replacement and other therapeutical interventions to modulate TH status.

scholarly journals T3:T4 Ratio Can Distinguish Between Adaptive Changes and True Subclinical Hypothyroidism in Older Adults

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 229-229
Author(s):  
Enoch Abbey ◽  
John McGready ◽  
Eleanor Simonsick ◽  
Jennifer Mammen
Keyword(s):  
Older Adults ◽  
Thyroid Hormone ◽  
Clinical Decision Making ◽  
Hormone Replacement ◽  
Primary Hypothyroidism ◽  
Free T4 ◽  
Cross Sectional ◽  
Adaptive Changes ◽  
C Statistic ◽  
Central Adaptation

Abstract Because of heterogeneity in hormonal aging,1 we believe isolated elevated TSH is insufficient to drive clinical decision making for thyroid hormone replacement in older adults. We performed a cross-sectional study involving 63 older adult participants of the BLSA in order to assess the diagnostic value of individual hormone levels or free T3: free T4 ratio for differentiating thyroid-aging phenotypes. We defined two phenotypic groups, central adaptation and primary hypothyroidism, both with a rising TSH and with a rising or falling FT4 respectively. Fifty-four percent of study participants were male, the average age was 78.8 years, and 66.7% had the primary hypothyroidism phenotype. The unadjusted odds ratio of having the central adaptation phenotype is 23.40 (95% CI 3.66-149.73) for every unit increase in the FT3:FT4 ratio. The ROC curve had a C-statistic of 0.815. Similarly, FT4 alone distinguished the phenotypes with a C-statistic of 0.864. In contrast, TSH and FT3 were not predictive (C-statistic of 0.617, and 0.479 respectively). When the analysis is limited to the 24 individuals with elevated TSH, the ratio remains predictive (0.839). Both the higher FT4 and the lower ratio found in individuals with adaptive changes are consistent with a physiology similar to the adaptations seen in acute illness. This supports the hypothesis that elevated TSH can represent a response to stressors with aging and doesn’t always warrant treatment with thyroid hormone. Our findings suggest that full thyroid function panel can be used to make better diagnostic decisions in older adults.

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