Early Levothyroxine Post Radioactive Iodine

Prevention of Overt Hypothyroidism Following Radioactive Iodine Therapy for Graves' Disease

The study will try to answer the question of whether early treatment with levothyroxine at 4 weeks after radioactive iodine for Graves'disease will prevent overt hypothyroidism (low thyroid hormone levels).

Inclusion criteria:

-all adult patients (ages 18-70 years) with Graves' Disease (GD) who will receive radioactive iodine (RAI) ablation of the thyroid gland for treatment of GD

Exclusion criteria:

• clinically manifest Graves' ophthalmopathy (GO)
• recent (<1 yr.) history of arrhythmias or any history of ventricular arrhythmias
• preexistent cardiomyopathy
• malnutrition
• psychiatric history that could get worse if patient remains persistently hyperthyroid
• unlikely to return for the planned follow-up visits
• unlikely to comply with the blood drawing schedule
• unlikely to complete the hypothyroid-Health Related Quality of Life (HDQL) and Thyroid Specific (TSQ) questionnaires