What are the treatment options for hyperthyroidism?

Treatment Options for Hyperthyroidism

The three main treatment options for hyperthyroidism are antithyroid medications (methimazole or propylthiouracil), radioactive iodine ablation, and surgical thyroidectomy, with the choice depending on the underlying cause, patient factors, and contraindications to specific treatments. 1, 2

Causes of Hyperthyroidism

• Graves' disease (70% of cases) - autoimmune condition
• Toxic nodular goiter (16% of cases) - autonomous functioning nodules
• Thyroiditis (3% of cases) - inflammation causing release of stored thyroid hormone
• Medication-induced (9% of cases) - amiodarone, tyrosine kinase inhibitors, immune checkpoint inhibitors 3

Antithyroid Medications

Methimazole (Preferred First-Line)

• Dosing: Can be given once daily
• Efficacy: More effective than propylthiouracil in normalizing thyroid levels
• Starting dose: 15-30 mg daily depending on severity 4
• Target: Maintain free T4 or FTI in high-normal range using lowest possible dose 5

Propylthiouracil (PTU)

• Indications:
  • Patients intolerant to methimazole
  • First trimester of pregnancy
  • Preparation for thyroidectomy or radioactive iodine therapy 6
• Dosing: Usually taken 3 times daily (every 8 hours)
• Starting dose: 100-150 mg three times daily 6, 4

Treatment Regimens

• Titration method: Use lowest dose to maintain euthyroidism for 12-18 months
• Block-and-replace method: Higher dose of antithyroid drug plus thyroid hormone replacement
• Monitoring: Measure free T4 or FTI every 2-4 weeks initially 5, 7
• Duration: Standard course is 12-18 months, with 50% risk of recurrence
• Long-term option: Extended treatment (5-10 years) reduces recurrence rate to 15% 3

Side Effects of Antithyroid Drugs

• Common: Rash, urticaria, arthralgia, fever
• Serious:
  • Agranulocytosis (presents with sore throat and fever)
  • Severe liver problems (can lead to liver failure)
  • Vasculitis 5, 6
• Monitoring: Complete blood count if symptoms develop; discontinue medication if abnormal 5

Radioactive Iodine (RAI) Ablation

• Most widely used treatment in the United States 1
• Best for: Toxic nodular goiter, recurrent Graves' disease after medication failure
• Contraindications: Pregnancy, breastfeeding 5, 3
• Outcome: Often results in permanent hypothyroidism requiring lifelong thyroid hormone replacement

Surgical Thyroidectomy

• Indications:
  • Large goiters causing compressive symptoms
  • Suspicious thyroid nodules
  • Patients who fail or cannot tolerate other treatments
  • Pregnant women who cannot tolerate antithyroid drugs 3, 2
• Preparation: Patients should be rendered euthyroid with antithyroid drugs before surgery 1

Adjunctive Treatments

• Beta blockers (e.g., propranolol): Control symptoms like tachycardia, tremor, and anxiety until definitive treatment reduces thyroid hormone levels 5, 8
• Supportive care: For thyroiditis-induced thyrotoxicosis, which is usually self-limiting 2

Special Populations

Pregnancy

• First-line treatment: Propylthiouracil in first trimester, can switch to methimazole after
• Goal: Use lowest possible dose to maintain free T4 in high-normal range
• Monitoring: Regular thyroid function tests and fetal monitoring 5

Thyroid Storm (Thyrotoxic Crisis)

• Emergency treatment includes:
  • Propylthiouracil or methimazole
  • Beta blockers (propranolol 60-80 mg every 4-6 hours)
  • Saturated solution of potassium iodide
  • Dexamethasone
  • Supportive care (oxygen, antipyretics) 8
• Alternative: Calcium channel blockers (diltiazem, verapamil) when beta blockers are contraindicated 8

Treatment Selection Considerations

• Patient age: Elderly patients may benefit from definitive treatment (RAI or surgery)
• Cardiac status: Higher risk of complications in patients with pre-existing heart disease
• Pregnancy status: Medication is first-line during pregnancy
• Disease severity: More severe hyperthyroidism may require combination therapy initially
• Patient preference: Long-term medication vs. definitive treatment 8, 2

Remember that untreated hyperthyroidism can lead to serious complications including cardiac arrhythmias, heart failure, osteoporosis, and increased mortality, making prompt and effective treatment essential 2.