From the Guidelines
Hyperthyroidism and thyrotoxicosis are distinct clinical concepts, with hyperthyroidism referring to excessive thyroid hormone production and thyrotoxicosis referring to the clinical syndrome of excess thyroid hormone action, regardless of the source. The most recent and highest quality study, 1, provides guidance on the management of thyrotoxicosis, particularly in the context of immune checkpoint inhibitor therapy. According to this study, the management of thyrotoxicosis depends on the severity of symptoms, with asymptomatic or mildly symptomatic patients (G1) able to continue immune checkpoint inhibitor therapy and receive beta-blockers for symptomatic relief, while those with moderate to severe symptoms (G2-G4) may require holding or discontinuing therapy and receiving more intensive treatment, including endocrine consultation and possible hospitalization.
Key points to consider in the management of hyperthyroidism and thyrotoxicosis include:
- The use of TSH and FT4 levels for case detection in symptomatic patients, with T3 levels helpful in highly symptomatic patients with minimal FT4 elevations
- The consideration of TSH receptor antibody testing in patients with clinical features and suspicion of Graves' disease
- The importance of close monitoring of thyroid function in patients with thyrotoxicosis, particularly those with transient subacute thyroiditis, to catch the transition to hypothyroidism
- The use of beta-blockers, such as propranolol, for symptomatic relief in patients with thyrotoxicosis
- The consideration of antithyroid medications, such as methimazole, or nonreversible thyroid ablation therapy, such as radioactive iodine or surgery, in patients with hyperthyroidism or persistent thyrotoxicosis.
Overall, the management of hyperthyroidism and thyrotoxicosis requires a careful consideration of the underlying cause, severity of symptoms, and individual patient factors, with a focus on minimizing morbidity, mortality, and improving quality of life.
From the Research
Hyperthyroidism vs Thyrotoxicosis
- Hyperthyroidism is an excessive concentration of thyroid hormones in tissues caused by increased synthesis of thyroid hormones, excessive release of preformed thyroid hormones, or an endogenous or exogenous extrathyroidal source 2
- Thyrotoxicosis has multiple etiologies, manifestations, and potential therapies, and appropriate treatment requires an accurate diagnosis and is influenced by coexisting medical conditions and patient preference 3, 4, 5
Causes of Hyperthyroidism and Thyrotoxicosis
- The most common causes of an excessive production of thyroid hormones are Graves' disease, toxic multinodular goiter, and toxic adenoma 2
- The most common cause of an excessive passive release of thyroid hormones is painless (silent) thyroiditis, although its clinical presentation is the same as with other causes 2
- Other causes of thyrotoxicosis include subclinical hyperthyroidism, hyperthyroidism in patients with Graves' ophthalmopathy, and management of other miscellaneous causes of thyrotoxicosis 3, 4, 5
Treatment of Hyperthyroidism and Thyrotoxicosis
- Hyperthyroidism caused by overproduction of thyroid hormones can be treated with antithyroid medications (methimazole and propylthiouracil), radioactive iodine ablation of the thyroid gland, or surgical thyroidectomy 2
- The choice of treatment depends on the underlying diagnosis, the presence of contraindications to a particular treatment modality, the severity of hyperthyroidism, and the patient's preference 2
- Long-term treatment with low doses of methimazole seems to prevent relapse in Graves' disease in patients above 35 years of age 6