A 75-year-old woman comes to the office after 2 months of heat intolerance, sweating, and palpitations. The patient has lost significant weight recently despite increasing her dietary intake. Medical history is notable only for hypertension, for which she takes amlodipine. Temperature is 37.2 C (99 F), blood pressure is 116/80 mm Hg, pulse is 120/min and regular, and respirations are 18/min. Physical examination shows a nontender, diffuse swelling in the front of her neck that moves upward with swallowing. There is no proptosis or pretibial myxedema. Fine hand tremors and hyperreflexia are noted on neurological examination. Laboratory results are as follows:
| Leukocytes | Normal |
| Serum creatinine | 1.0 mg/dL |
| TSH | <0.001 µU/mL |
| Triiodothyronine (T3) | 500 ng/dL |
| Free thyroxine (T4) | 4.7 ng/dL (0.9-1.7 ng/dL) |
Radioactive iodine uptake at 24 hours is significantly increased and homogenously distributed throughout the thyroid gland. The patient is started on a beta blocker. Which of the following is the best next step in management of this patient?
Show Explanatory Sources
This patient has severe hyperthyroidism along with a diffuse goiter and homogeneous radioiodine uptake consistent with Graves disease. The 3 modalities for treatment of Graves disease include antithyroid drugs (ATDs) (eg, propylthiouracil, methimazole), radioactive iodine (RAI), and thyroidectomy. Most patients will require RAI or thyroidectomy.
Patients with mild disease, small goiters, and low TSH receptor antibody titers can be managed with an ATD alone and have a 50% likelihood of permanent remission. ATD therapy alone is also used in pregnant women or older patients with limited life expectancy.
In patients who have significant symptoms and thyroid hormone levels >2-3 times normal, an ATD with a beta blocker is initially recommended to stabilize the patient before definitive treatment with RAI or thyroidectomy. Pretreatment with ATDs is also recommended for patients at increased risk (eg, elderly, significant comorbidities) for complications due to the transient worsening of hyperthyroidism following RAI treatment. In light of this patient's age and severe thyrotoxicosis, treatment with an ATD is recommended prior to definitive treatment with RAI (Choice B).
(Choice A) Beta blockers alone are usually sufficient during the thyrotoxic phase of silent or painless thyroiditis but would not be adequate treatment for patients with Graves disease and significant thyrotoxicosis.
(Choice D) Potassium iodide inhibits thyroid hormone synthesis and release. It is used mainly in preparation for thyroidectomy in Graves disease and for treating thyroid storm.
(Choice E) Systemic glucocorticoids are used for thyroid storm, type 2 amiodarone-induced thyrotoxicosis, and severe cases of subacute (de Quervain) thyroiditis.
(Choice F) Thyroidectomy is preferred over RAI in some patients with Graves hyperthyroidism, especially those with a large goiter or a coexisting thyroid nodule suspicious for cancer. Thyroidectomy is also advised for patients with severe Graves ophthalmopathy in whom RAI is contraindicated.
Educational objective:
Graves disease can be treated with antithyroid drugs, radioactive iodine, or thyroidectomy. Antithyroid drugs are used for patients with mild disease who are likely to have a permanent remission. They are also used in preparation for treatment with radioactive iodine in patients with significant hyperthyroidism or who are at increased risk of complications.