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 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.

SYSTOLIC TIME INTERVALS (STI) AS INDICATORS OF MYOCARDIAL THYROID HORMONE EFFECT

1978 ◽  
Vol 87 (3) ◽  
pp. 507-515 ◽  
Author(s):  
J. Chakravarty ◽  
A. R. Guansing ◽  
S. Chakravarty ◽  
C. V. Hughes
Keyword(s):  
Thyroid Hormone ◽  
Systolic Time Intervals ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Ejection Time ◽  
Time Intervals ◽  
Left Ventricular Ejection Time ◽  
Hormone Effect ◽  
Systolic Time ◽  
Ventricular Ejection Time

ABSTRACT Systolic time intervals consisting of indices of electromechanical systole (QS2-I), left ventricular ejection time (LVET-I) and pre-ejection period (PEP-I) were calculated serially during therapy in 12 euthyroid, 9 hypothyroid and 9 hyperthyroid individuals. These parameters were analyzed sequentially together with the changes in serum thyroxine (T4), triiodothyronine (T3) and thyrotrophin (TSH) in order to determine the sensitivity of these non-invasive procedures in monitoring peripheral thyroid hormone effect. The results are expreseed in mean ± sem. QS2-I (506.3 ± 8.2 ms) and PEP-I (102.9 ± 4.2) were shortened (P < 0.02 and P < 0.001, respectively) in hyperthyroidism and prolonged (579.3 ± 7.3 and 169.6 ± 3.6 ms) in hypothyroidism (P < 0.01 and P < 0.001, respectively) compared to euthyroid controls (538.1 ± 8.8 and 130.3 ± 5.3 ms), while LVET-I did not change significantly in either condition. Simultaneous determinations of circulating T4, T3 and TSH showed changes appropriate to both hypo- and hyperthyroid states. In 2 patients with T3-thyrotoxicosis, PEP-I was decreased to an average of 103.1 ms, while in 2 patients with compensated hypothyroidism (normal T4 but elevated TSH) this was prolonged to 163.7 ms (average) compared to euthyroid controls. During treatment the hypothyroid group showed significant sequential correlation of TSH and PEP-I. In the hyperthyroid individuals, PEP-I correlated significantly with T4 and T3. PEP-I may be a useful, sensitive, quantitative biologic indicator of thyroid hormone effect on myocardial function.

Systolic Time Intervals and Hydralazine

CHEST Journal ◽  
1982 ◽  
Vol 81 (5) ◽  
pp. 660 ◽  
Author(s):  
George Louridas ◽  
Demetrios Patakas ◽  
Nicholas Galanis ◽  
Marianna Kakoura ◽  
Costas Stavropoulos
Keyword(s):  
Systolic Time Intervals ◽  
Time Intervals ◽  
Systolic Time
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