From the Guidelines
The workup for hyperthyroidism should begin with thyroid function tests, specifically TSH, free T4, and free T3, as recommended by the USPSTF 1. A suppressed TSH with elevated free T4 and/or free T3 confirms hyperthyroidism. Once hyperthyroidism is confirmed, determining the etiology is essential. Order thyroid antibodies including thyroid-stimulating immunoglobulin (TSI) and thyroid peroxidase antibodies (TPO) to evaluate for Graves' disease, the most common cause. A radioactive iodine uptake scan can differentiate between causes of hyperthyroidism - Graves' disease typically shows diffuse increased uptake, while toxic nodules show focal uptake, and thyroiditis shows decreased uptake. Thyroid ultrasound is useful to evaluate nodules and gland morphology. Complete blood count and comprehensive metabolic panel should be included to assess for complications. For patients with suspected Graves' ophthalmopathy, orbital imaging may be necessary. Initial management typically includes beta-blockers like propranolol (10-40mg three to four times daily) to control symptoms while definitive treatment is planned, as supported by recent studies 1. Definitive treatment options include antithyroid medications (methimazole 5-30mg daily or propylthiouracil 100-300mg three times daily), radioactive iodine ablation, or thyroidectomy, depending on the cause, patient age, comorbidities, and preferences. This systematic approach ensures proper diagnosis and guides appropriate treatment selection. Key considerations in management include the patient's overall health status, the presence of any comorbid conditions, and the potential risks and benefits of each treatment option. By following this approach, clinicians can provide effective care for patients with hyperthyroidism and improve outcomes. The use of beta-blockers, such as propranolol, is particularly important in managing symptoms and preventing complications in patients with thyrotoxicosis or symptomatic hyperthyroidism 1. Overall, a comprehensive and individualized approach to the diagnosis and treatment of hyperthyroidism is essential for optimizing patient outcomes.
From the Research
Hyperthyroidism Workup
- Hyperthyroidism is a condition that affects approximately 0.2% to 1.4% of people worldwide, with overt hyperthyroidism defined as suppressed thyrotropin and high concentration of triiodothyronine (T3) and/or free thyroxine (FT4) 2
- The most common cause of hyperthyroidism is Graves' disease, with a global prevalence of 2% in women and 0.5% in men 2
- Common symptoms of thyrotoxicosis include anxiety, insomnia, palpitations, unintentional weight loss, diarrhea, and heat intolerance 2
Diagnosis
- Etiology can typically be established based on clinical presentation, thyroid function tests, and thyrotropin-receptor antibody status 2
- Thyroid scintigraphy is recommended if thyroid nodules are present or the etiology is unclear 2
- Thyroid function tests, including thyrotropin and free thyroxine (FT4) levels, are essential for diagnosing hyperthyroidism 2
Treatment
- Treatment options for overt hyperthyroidism from autonomous thyroid nodules or Graves' disease include antithyroid drugs, radioactive iodine ablation, and surgery 2
- Thionamides, such as methimazole and propylthiouracil, are commonly used as first-line treatment for Graves' hyperthyroidism 3, 4
- Methimazole is preferred over propylthiouracil due to its better side-effect profile and higher efficacy 3, 5
- Propylthiouracil may be considered as a first-line agent in the treatment of Graves' disease during pregnancy, due to a possible association between methimazole and fetal anomalies 6
Special Considerations
- In pregnant women, propylthiouracil is often preferred over methimazole due to concerns about methimazole's potential effects on the fetus 6
- In patients with severe hyperthyroidism, higher doses of methimazole (30 mg/d) may be more effective than lower doses (15 mg/d) or propylthiouracil (300 mg/d) 5
- Treatment choices should be individualized and patient-centered, taking into account the patient's specific needs and circumstances 2