From the Guidelines
In patients with TSH hyperthyroidism, the primary goal is to normalize thyroid hormone levels and alleviate symptoms, with treatment options including antithyroid medications, radioactive iodine therapy, or thyroid surgery, as recommended by the USPSTF 1. The diagnosis of hyperthyroidism is typically made based on a combination of clinical symptoms, such as weight loss, palpitations, and tremors, and laboratory tests, including a suppressed TSH level and elevated free T4 and T3 levels.
- Common causes of hyperthyroidism include Graves' disease, toxic multinodular goiter, and thyroiditis, with risk factors including female sex, advancing age, and a personal or family history of thyroid disease 1.
- The USPSTF recommends treatment for patients with a TSH level that is persistently low, with the goal of normalizing thyroid hormone levels and preventing long-term complications, such as atrial fibrillation and osteoporosis 1.
- Treatment options for hyperthyroidism include antithyroid medications, such as methimazole, radioactive iodine therapy, and thyroid surgery, with the choice of treatment depending on the underlying cause of the hyperthyroidism, the severity of symptoms, and the patient's overall health status.
- Regular monitoring of thyroid function tests is essential during treatment, with the goal of normalizing TSH and thyroid hormone levels, and preventing potential side effects of treatment, such as rash, joint pain, and agranulocytosis 1.
From the FDA Drug Label
Once clinical evidence of hyperthyroidism has resolved, the finding of a rising serum TSH indicates that a lower maintenance dose of methimazole should be employed. Once clinical evidence of hyperthyroidism has resolved, the finding of an elevated serum TSH indicates that a lower maintenance dose of propylthiouracil should be employed.
The presence of a rising serum TSH in patients with hyperthyroidism who are being treated with methimazole or propylthiouracil indicates that the dose of the medication should be lowered. This is because a rising TSH level suggests that the patient's thyroid hormone levels are decreasing, and a lower dose of the medication is needed to maintain euthyroidism.
- Key points: + A rising serum TSH level indicates that the dose of methimazole or propylthiouracil should be lowered. + The goal of treatment is to maintain euthyroidism, not to suppress TSH levels. + Thyroid function tests should be monitored periodically during therapy to adjust the dose of the medication as needed 2, 3.
From the Research
Definition and Causes of Hyperthyroidism
- 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 4.
- The most common causes of an excessive production of thyroid hormones are Graves disease, toxic multinodular goiter, and toxic adenoma 4, 5.
- Hyperthyroidism can also be caused by subacute granulomatous thyroiditis, drugs such as amiodarone, tyrosine kinase inhibitors, and immune checkpoint inhibitors 5.
Diagnosis of Hyperthyroidism
- Clinical suspicion of hyperthyroidism should be confirmed by biochemical tests, such as low TSH, high free thyroxine (FT4), or high free tri-iodothyonine (FT3) 5.
- A nosological diagnosis should be done to find out which disease is causing the hyperthyroidism, using tools such as TSH-receptor antibodies, thyroid peroxidase antibodies, thyroid ultrasonography, and scintigraphy 5.
Treatment of Hyperthyroidism
- Hyperthyroidism caused by overproduction of thyroid hormones can be treated with antithyroid medications, radioactive iodine ablation of the thyroid gland, or surgical thyroidectomy 4.
- 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 4.
- Graves' hyperthyroidism is preferably treated with antithyroid drugs, but long-term treatment with antithyroid drugs is feasible and associated with fewer recurrences than short-term treatment 5.
- Toxic nodular goitre is mostly treated with radioiodine (131I) or thyroidectomy, and is rarely treated with radiofrequency ablation 5.