Nieuwe ATA-Richtlijn houdt vast aan levothyroxine bij hypothyreoïdie

Bron: Thyroid. December 2014, 24(12): 1670-1751. doi:10.1089/thy.2014.0028

A number of recent advances in our understanding of thyroid physiology may shed light on why some patients feel unwell while taking levothyroxine monotherapy. The purpose of this task force was to review the goals of levothyroxine therapy, the optimal prescription of conventional levothyroxine therapy, the sources of dissatisfaction with levothyroxine therapy, the evidence on treatment alternatives, and the relevant knowledge gaps. We wished to determine whether there are sufficient new data generated by well-designed studies to provide reason to pursue such therapies and change the current standard of care. This document is intended to inform clinical decision-making on thyroid hormone replacement therapy; it is not a replacement for individualized clinical judgment.

Guidelines for the Treatment of Hypothyroidism: Prepared by the American Thyroid Association Task Force on Thyroid Hormone Replacement
Jacqueline Jonklaas, Antonio Bianco, Andrew Bauer, Kenneth Burman, Anne Cappola, Francesco Celi, David Cooper, Brian Kim, Robin Peeters, Sara Rosenthal, Anna Sawka

New ATA Guidelines stick with levothyroxine for hypothyroidism
Medscape / Schildklierforum

Als je schildklier te weinig of geen hormoon maakt
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Methods

Task force members identified 24 questions relevant to the treatment of hypothyroidism. The clinical literature relating to each question was then reviewed. Clinical reviews were supplemented, when relevant, with related mechanistic and bench research literature reviews, performed by our team of translational scientists. Ethics reviews were provided, when relevant, by a bioethicist. The responses to questions were formatted, when possible, in the form of a formal clinical recommendation statement. When responses were not suitable for a formal clinical recommendation, a summary response statement without a formal clinical recommendation was developed. For clinical recommendations, the supporting evidence was appraised, and the strength of each clinical recommendation was assessed, using the American College of Physicians system. The final document was organized so that each topic is introduced with a question, followed by a formal clinical recommendation. Stakeholder input was received at a national meeting, with some subsequent refinement of the clinical questions addressed in the document. Consensus was achieved for all recommendations by the task force.

Results

We reviewed the following therapeutic categories: (i) levothyroxine therapy, (ii) non–levothyroxine-based thyroid hormone therapies, and (iii) use of thyroid hormone analogs. The second category included thyroid extracts, synthetic combination therapy, triiodothyronine therapy, and compounded thyroid hormones.

Conclusions

We concluded that levothyroxine should remain the standard of care for treating hypothyroidism. We found no consistently strong evidence for the superiority of alternative preparations (e.g., levothyroxine–liothyronine combination therapy, or thyroid extract therapy, or others) over monotherapy with levothyroxine, in improving health outcomes. Some examples of future research needs include the development of superior biomarkers of euthyroidism to supplement thyrotropin measurements, mechanistic research on serum triiodothyronine levels (including effects of age and disease status, relationship with tissue concentrations, as well as potential therapeutic targeting), and long-term outcome clinical trials testing combination therapy or thyroid extracts (including subgroup effects). Additional research is also needed to develop thyroid hormone analogs with a favorable benefit to risk profile.

Clearly, there have been great advances in the understanding and management of TH replacement, but nevertheless more research is needed. Areas in which future research should be encouraged include, but are not limited to:

1. Strategies to avoid iatrogenic thyroid disease in individuals treated for hypothyroidism.
2. Research into strategies to aid compliance with LT4 therapy.
3. Better understanding of maternal-fetal physiology during pregnancy with development of improved titration of LT4 therapy in hypothyroid pregnant patients.
4. Further studies of soft gel LT4 capsules to determine their proper place in the therapeutic armamentarium.
5. Further study, and improved standardization, of compounded formulations of LT4 and/or LT3.
6. Development of additional biomarkers of euthyroidism, which may supplement the use of serum TSH as a biomarker.
7. Development of a better understanding of how T3 levels are affected by age and disease status, with consideration of reference ranges indexed to age and health status.
8. Clarification of the relative importance of maintaining specific serum T3 concentrations.
9. Research into the relationship between serum T3 and T3 concentrations in specific tissues.
10. Development of more accurate assays to measure serum concentrations of FT3, total T3, and FT4.
11. Development of a sustained release T3 preparation that can then be prospectively tested in clinical trials (e.g., in combination with LT4 in a physiologic ratio of about 14:1).
12. In the absence of the availability of a sustained release T3 preparation, study of when, if ever, the use of LT3 would be beneficial in selected patients with apparent decreased T4 to T3 conversion and disproportionately low serum T3 levels.
13. Long-term outcome research using thyroid extracts that includes documentation of the consequences of excursions in serum T3 concentrations.
14. Development of TH analogs with a favorable benefit to risk profile.
15. Pursuit of research into developing thyroid stem cells as a potential avenue for understanding thyrocyte physiology and as a possible future treatment for hypothyroidism.