UZH-Logo

Maintenance Infos

Timing of thyroxine dose adjustment in hypothyroid patients: when are TSH levels stable?


Kohler, S; Senn, O; Saleh, L; Wass, J A H; Schmid, C H (2014). Timing of thyroxine dose adjustment in hypothyroid patients: when are TSH levels stable? Journal of Thyroid Disorders & Therapy, 3(3):online.

Abstract

BACKGROUND: Serum TSH is the target hormone by which adequate thyroid hormone supply can easily be monitored in patients with primary hypothyroidism. It is however controversial when TSH should be measured before thyroxine dose adjustments are made: 4 to 8 weeks are recommended. We looked at the time required to reach stable TSH levels in hypothyroid patients. METHODS: We studied patients with newly diagnosed hypothyroidism (TSH >10 mU/l and fT4 <12.3 pmol/l). Treatment was initiated with thyroxine 50 μg/d if there was a history of cardiac disease and 100 μg/d otherwise. Blood pressure, weight and TSH, fT4, fT3, cystatin C and creatinine were measured once a week. Thyroxine dose was increased by 25 μg every 8 weeks until TSH normalised. RESULTS: 12 patients with a mean TSH at baseline of 57.6 mU/l (range 11.3–151.8 mU/l) gave informed consent. They were followed for 8 to 24 weeks. After adjusting for the number of observation periods for each patient, the mean time to achieving stable TSH was 3.5 weeks (95% CI, 2.6-4.3 weeks), whereby stable TSH was defined as the value reached on a certain replacement dose after which TSH fluctuated by no more than +/- 2 mU/l during the remaining weeks of an 8 week observation period (median TSH at study end 4.7 mU/l). CONCLUSIONS: TSH did not change significantly after a mean of 3.5 weeks after the introduction of thyroxine. Dose changes can therefore be made after 4 weeks of treatment, longer periods are unnecessary.

BACKGROUND: Serum TSH is the target hormone by which adequate thyroid hormone supply can easily be monitored in patients with primary hypothyroidism. It is however controversial when TSH should be measured before thyroxine dose adjustments are made: 4 to 8 weeks are recommended. We looked at the time required to reach stable TSH levels in hypothyroid patients. METHODS: We studied patients with newly diagnosed hypothyroidism (TSH >10 mU/l and fT4 <12.3 pmol/l). Treatment was initiated with thyroxine 50 μg/d if there was a history of cardiac disease and 100 μg/d otherwise. Blood pressure, weight and TSH, fT4, fT3, cystatin C and creatinine were measured once a week. Thyroxine dose was increased by 25 μg every 8 weeks until TSH normalised. RESULTS: 12 patients with a mean TSH at baseline of 57.6 mU/l (range 11.3–151.8 mU/l) gave informed consent. They were followed for 8 to 24 weeks. After adjusting for the number of observation periods for each patient, the mean time to achieving stable TSH was 3.5 weeks (95% CI, 2.6-4.3 weeks), whereby stable TSH was defined as the value reached on a certain replacement dose after which TSH fluctuated by no more than +/- 2 mU/l during the remaining weeks of an 8 week observation period (median TSH at study end 4.7 mU/l). CONCLUSIONS: TSH did not change significantly after a mean of 3.5 weeks after the introduction of thyroxine. Dose changes can therefore be made after 4 weeks of treatment, longer periods are unnecessary.

Altmetrics

Downloads

27 downloads since deposited on 09 Oct 2014
23 downloads since 12 months
Detailed statistics

Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:04 Faculty of Medicine > University Hospital Zurich > Clinic for Endocrinology and Diabetology
04 Faculty of Medicine > University Hospital Zurich > Institute of General Practice
Dewey Decimal Classification:610 Medicine & health
Language:English
Date:2014
Deposited On:09 Oct 2014 14:25
Last Modified:05 Apr 2016 18:24
Publisher:Omics Publishing Group
ISSN:2167-7948
Publisher DOI:https://doi.org/10.4172/2167-7948.1000161
Permanent URL: https://doi.org/10.5167/uzh-99328

Download

[img]
Preview
Content: Published Version
Filetype: PDF
Size: 314kB
View at publisher

TrendTerms

TrendTerms displays relevant terms of the abstract of this publication and related documents on a map. The terms and their relations were extracted from ZORA using word statistics. Their timelines are taken from ZORA as well. The bubble size of a term is proportional to the number of documents where the term occurs. Red, orange, yellow and green colors are used for terms that occur in the current document; red indicates high interlinkedness of a term with other terms, orange, yellow and green decreasing interlinkedness. Blue is used for terms that have a relation with the terms in this document, but occur in other documents.
You can navigate and zoom the map. Mouse-hovering a term displays its timeline, clicking it yields the associated documents.

Author Collaborations