What are the treatment options for hyperthyroidism?

Treatment Options for Hyperthyroidism

The primary treatment options for hyperthyroidism include antithyroid medications (methimazole or propylthiouracil), radioactive iodine ablation, and surgical thyroidectomy, with the choice depending on the underlying cause, severity of symptoms, and patient-specific factors. 1, 2

Causes of Hyperthyroidism

• Graves' disease (70% of cases), toxic multinodular goiter (16%), subacute thyroiditis (3%), and drug-induced hyperthyroidism (9%) are the most common causes 2
• Diagnosis is confirmed by low TSH with elevated free T4 and/or T3 levels, followed by additional testing to determine the specific etiology 2

Pharmacological Treatment Options

Antithyroid Medications

• Methimazole (MMI):

  • First-line agent for most patients with hyperthyroidism 3
  • Recommended starting dose: 10-30 mg once daily 4
  • Advantages: once-daily dosing, fewer major side effects, more cost-effective 4
  • More effective than propylthiouracil in normalizing thyroid hormone levels when used as a single daily dose 5

• Propylthiouracil (PTU):

  • Not recommended as first-line therapy due to risk of severe liver failure 3
  • Only indicated when:
    • Patient is intolerant to methimazole 6
    • During first trimester of pregnancy 4
    • When surgery or radioactive iodine is not appropriate 6
  • Typical dosing: 100-300 mg every 6 hours 4
  • FDA warning: can cause severe liver problems including liver failure requiring transplantation 6

Beta-Blockers

• Used for symptomatic relief (e.g., tachycardia, tremor) while waiting for antithyroid medications to take effect 7
• Options include atenolol or propranolol 7
• Particularly important in patients with cardiac symptoms related to hyperthyroidism 7

Definitive Treatment Options

Radioactive Iodine (RAI) Therapy

• Most widely used definitive treatment in the United States 1
• Particularly effective for toxic nodular goiter 2
• Contraindicated during pregnancy 7
• Antithyroid drugs should be stopped at least one week prior to RAI to reduce risk of treatment failure 3
• Patients often develop hypothyroidism after treatment, requiring lifelong thyroid hormone replacement 7

Thyroidectomy (Surgical Removal)

• Recommended as near-total or total thyroidectomy 3
• Indications include:
  • Large goiters causing compressive symptoms
  • Suspicious nodules
  • Failure of medical therapy
  • Patient preference
  • Severe ophthalmopathy
• Requires lifelong thyroid hormone replacement post-surgery 7

Treatment Approach Based on Cause

Graves' Disease

• Initial approach: Antithyroid drugs (preferably methimazole) for 12-18 months 2
• Recurrence occurs in approximately 50% of patients after standard course 2
• Risk factors for recurrence: age <40 years, high initial FT4 levels (≥40 pmol/L), high TSH-binding inhibitory immunoglobulins, and large goiter 2
• Long-term antithyroid treatment (5-10 years) associated with fewer recurrences (15%) 2
• Definitive treatment with RAI or thyroidectomy recommended if antibodies against TSH-receptor remain elevated after 6 months of treatment 3

Toxic Nodular Goiter

• Usually treated definitively with radioactive iodine or surgery 2
• Antithyroid drugs may be used for symptom control before definitive treatment 1

Thyroiditis

• Self-limited condition with initial hyperthyroid phase followed by hypothyroid phase 7
• Treatment focuses on symptom management with beta-blockers 7
• Close monitoring of thyroid function every 2-3 weeks to detect transition to hypothyroidism 7
• Typically resolves within weeks with supportive care 7

Special Considerations

Pregnancy

• PTU is preferred during first trimester due to potential risk of methimazole-associated birth defects (aplasia cutis, choanal/esophageal atresia) 4
• Consider switching to methimazole after first trimester due to PTU's risk of liver toxicity 6
• Both medications are compatible with breastfeeding 7, 4

Severe Hyperthyroidism/Thyroid Storm

• Requires hospitalization and aggressive management 7
• Treatment includes:
  • Beta-blockers for symptom control
  • High-dose antithyroid drugs
  • Supportive care (hydration)
  • Possible addition of steroids, potassium iodide solution (SSKI), or other measures 7
  • Endocrinology consultation recommended 7

Monitoring and Follow-up

• Regular monitoring of thyroid function tests (TSH, FT4) every 4-6 weeks initially 7
• Dose adjustments based on clinical response and laboratory values 7
• Monitoring for potential side effects of medications (agranulocytosis, liver dysfunction) 6
• Long-term follow-up even after successful treatment due to risk of recurrence or development of hypothyroidism 7