Evidence Based Use of LT4-LT3 Combinations in Treating Hypothyroidism Presented by F-Alizadeh

AGENDA

• Introduction
• What is the role of D1 and D2 pathways in the TSH feedback mechanism during LT4 treatment?
• What is the difference in thyroid hormone levels between mono and combination therapy?
• Is combination therapy effective  in dio2 polymorphism?
• Does autoimmunity play a role in persistent symptoms of  patients?
• How does thyroid function change in the peripheral marker?
• T4+T3 therapy: Is there a true effect on the clinical condition?
• What factors determine patients preference for treatment?
• Conclusion

Introduction

• Before 1970, the majority of patients with hypothyroidism were being treated by natural preparations of thyroid extracts, containing both T4 and T3 hormones Growing discontent with variable potency of thyroid extract products ,along with the decreased cost of LT4, caused an increase in the prescription of LT4
• Levothyroxine (LT4) monotherapy has been considered the standard treatment for hypothyroidism
• About 5%–10% of hypothyroid patients on T4 replacement therapy have persistent symptoms, despite normal TSH levels
• Some physicians hesitated to use LT4 monotherapy because they believed that the ideal thyroid hormone preparation should have a combination of LT4 and LT3 to simulate the metabolic effects of endogenous thyroid secretion