What are the symptoms and treatment options for Hyperthyroidism (excessive production of thyroid hormone)?

From the Guidelines

Hyperthyroidism should be treated with antithyroid medications, such as methimazole, or nonreversible thyroid ablation therapy, like radioactive iodine or surgery, particularly in patients with a TSH level that is undetectable or less than 0.1 mIU/L, to improve morbidity, mortality, and quality of life. When managing hyperthyroidism, it is crucial to consider the underlying cause, such as Graves' disease or nodular thyroid disease, as this may influence the treatment approach 1. Key considerations in treatment include:

• Antithyroid medications, like methimazole, which block hormone production
• Beta-blockers, such as propranolol, to manage symptoms like rapid heart rate and tremors
• Radioactive iodine therapy or thyroidectomy for long-term management
• Lifelong levothyroxine replacement after definitive treatment to maintain proper hormone levels Common symptoms of hyperthyroidism, such as weight loss, anxiety, and irregular heartbeat, should be monitored and addressed through treatment 1. The optimal treatment approach may vary depending on the individual patient's condition, and regular monitoring of thyroid function tests is essential to ensure proper hormone levels are maintained and to adjust medication dosages as needed.

From the FDA Drug Label

Thyroid function tests should be monitored periodically during therapy 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. Propylthiouracil is a prescription medicine used to treat people who have Graves’ disease with hyperthyroidism or toxic multinodular goiter.

Hyperthyroidism Treatment:

• Methimazole and propylthiouracil are used to treat hyperthyroidism.
• Thyroid function tests should be monitored periodically during therapy.
• Once clinical evidence of hyperthyroidism has resolved, a lower maintenance dose of the medication should be employed.
• The choice of medication depends on the patient's condition, such as pregnancy or other medical conditions.
• Methimazole and propylthiouracil can cause serious side effects, including liver problems, low white blood cell counts, and vasculitis.
• Patients should be closely monitored and report any symptoms of illness or side effects to their doctor immediately 2, 3, 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.
• 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 4.

Symptoms and Diagnosis of Hyperthyroidism

• Common symptoms of thyrotoxicosis include anxiety, insomnia, palpitations, unintentional weight loss, diarrhea, and heat intolerance 5.
• Patients with Graves disease may have a diffusely enlarged thyroid gland, stare, or exophthalmos on examination 5.
• Patients with toxic nodules may have symptoms from local compression of structures in the neck by the thyroid gland, such as dysphagia, orthopnea, or voice changes 5.
• Etiology can typically be established based on clinical presentation, thyroid function tests, and thyrotropin-receptor antibody status 5.

Treatment Options for Hyperthyroidism

• 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 4.
• Radioactive iodine ablation is the most widely used treatment in the United States 4.
• Methimazole (MMI) and propylthiouracil (PTU) are the main antithyroid drugs used for hyperthyroidism, with MMI being the drug of choice due to its widespread availability, longer half-life, and small number of severe side effects 6.
• Treatment options for overt hyperthyroidism from autonomous thyroid nodules or Graves disease include antithyroid drugs, radioactive iodine ablation, and surgery 5.
• Long-term methimazole (LT-MMI) treatment was found to be superior to radioiodine in patients with post-RAI relapse of hyperthyroidism, with faster achievement of euthyroidism and more sustained control of hyperthyroidism during 60 months of follow-up 7.

Comparison of Treatment Options

• A study comparing MMI 30 mg/d treatment with PTU 300 mg/d and MMI 15 mg/d treatment found that MMI 30 mg/d normalized FT4 in more patients than PTU 300 mg/d and MMI 15 mg/d at 12 weeks 8.
• MMI 15 mg/d was found to be suitable for mild and moderate GD, whereas MMI 30 mg/d was advisable for severe cases 8.
• PTU was not recommended for initial use due to higher adverse effects, especially mild hepatotoxicity 8.