T4/T3 Therapy in Hypothyroidism

University of Pennsylvania

Summary

This study will test whether 6 months of combination therapy with levothyroxine (LT4) plus liothyronine (LT3) is superior to LT4 plus placebo in participants with hypothyroidism who have residual symptoms of hypothyroidism with TSH levels within the reference range.

Description

.Participants will * Take LT4+LT3 or LT4+placebo for 6 months * Visit the clinic at the beginning and the end of the study for a blood test and to answer questionnaires. * Have blood tests checked at 6 and 13 weeks and symptom checks by text (weekly to monthly)

Eligibility

Age range: 18–70 years
Sex: All
Healthy volunteers: No

Detailed criteria

Inclusion Criteria: 1. Male or female, aged 18-70 years 2. Hypothyroidism due to either thyroid failure or total thyroidectomy for structural thyroid disease (nodules, benign goiter, or thyroid cancer) for at least 6 months 3. Taking 75-150 mcg per day LT4 and a minimum of 1.2 mcg/kg/day, with stable dose of LT4 for at least 3 months prior to enrollment 4. TSH of 0.5 to 4.0 mU/L within 2 months of enrollment 5. Persistent symptoms for at least 2 months, and a TSQ score of ≥ 5 6. For females of reproductive potential: use of highly effective contraception for at least 1 month prior to screenin…

Interventions

Drug
Liothyronine (L-T3)
Participants will either take LT3 with an LT4 dose that is reduced from baseline or they will take liothyronine placebo with their baseline LT4 dose.
Drug
Levothyroxine Sodium (LT4) Tablets
All participants will take levothyroxine.
Drug
Liothyronine (LT3) placebo
Identical placebo tablet without containing liothyronine

Location

Penn Medicine, Smilow Center for Translational Resarch,
Philadelphia, Pennsylvania