What are the treatment options for hyperthyroidism?

Treatment Options for Hyperthyroidism

The preferred first-line treatment for hyperthyroidism is methimazole, with radioactive iodine ablation and surgical thyroidectomy as definitive treatment options based on specific clinical scenarios. 1

Diagnosis and Initial Assessment

• Confirm hyperthyroidism with:
  • Suppressed TSH
  • Elevated Free T4 and/or Free T3
  • Determine etiology through clinical presentation, TSH receptor antibodies, thyroid ultrasonography, and thyroid scintigraphy (if nodules present or etiology unclear)

Treatment Options

Pharmacological Management

1. Antithyroid Medications:

   • Methimazole: First-line treatment for most patients

     • Dosing: 10-30 mg daily
     • Standard course: 12-18 months
     • Monitor for side effects: agranulocytosis, skin eruptions, hepatotoxicity 1

   • Propylthiouracil (PTU):

     • Alternative to methimazole
     • Preferred in first trimester of pregnancy
     • Dosing: 100-300 mg divided three times daily
     • Higher risk of severe liver injury, especially in pediatric patients 2
     • FDA indication: for patients intolerant to methimazole or when surgery/radioactive iodine is not appropriate 2

2. Symptomatic Treatment:

   • Beta-blockers (atenolol, propranolol) for all symptomatic patients
   • Addresses palpitations, tremor, anxiety, and tachycardia
   • Monitor for bradycardia, bronchospasm, and hypotension 1

Definitive Treatment Options

1. Radioactive Iodine Ablation:

   • Most widely used treatment in the United States 3
   • Particularly effective for toxic nodular goiter
   • Contraindicated in pregnancy
   • Often requires pre-treatment with antithyroid medications 1

2. Surgical Thyroidectomy:

   • Indicated for:
     • Large goiters causing compressive symptoms
     • Suspicious nodules
     • Patients who decline radioactive iodine
     • Pregnant women who cannot tolerate antithyroid drugs
   • Potential complications: hypoparathyroidism and recurrent laryngeal nerve injury 1

Treatment Selection Based on Etiology

Graves' Disease (70% of cases) 4

• First-line: Antithyroid drugs (methimazole preferred)
• Long-term treatment (5-10 years) associated with fewer recurrences (15%) than short-term treatment (12-18 months, 50% recurrence) 4
• Risk factors for recurrence: age <40 years, high FT4 concentrations (≥40 pmol/L), high TSH-binding inhibitory immunoglobulins, large goiter 4

Toxic Nodular Goiter (16% of cases) 4

• Preferred treatments: Radioactive iodine or thyroidectomy
• Antithyroid drugs not recommended long-term due to high relapse rates 5

Thyroiditis (3% of cases) 4

• Usually self-limiting, requiring only symptomatic treatment
• Beta-blockers for symptom control
• Steroids only in severe cases 4

Subclinical Hyperthyroidism

• TSH 0.1-0.45 mIU/L: Treatment generally not recommended except in elderly due to possible cardiovascular mortality risk 6
• TSH <0.1 mIU/L: Treatment recommended, particularly for patients >60 years or with/at risk for heart disease, osteopenia, or osteoporosis 6, 1

Special Populations

Pregnancy

• First trimester: Propylthiouracil preferred
• Second and third trimesters: Switch to methimazole
• Use lowest effective dose
• Radioactive iodine absolutely contraindicated 1, 2

Elderly (>65 years)

• Treatment recommended even for subclinical hyperthyroidism due to higher risk of cardiovascular complications 1

Monitoring and Follow-up

• Initial monitoring: Every 2-3 weeks until stable
• Once stable: Every 1-3 months
• Adjust medication dose based on thyroid function tests
• Monitor for medication side effects:
  • Agranulocytosis: Sore throat, fever, general malaise
  • Hepatotoxicity: Anorexia, pruritus, jaundice, right upper quadrant pain
  • Skin eruptions 1, 2

Common Pitfalls to Avoid

• Failing to recognize thyroid storm (life-threatening emergency)
• Missing the underlying cause of hyperthyroidism
• Overlooking pregnancy status before treatment selection
• Inadequate monitoring for medication side effects
• Ignoring cardiovascular complications 1

Beta-blockers should be considered in all symptomatic patients regardless of the chosen definitive treatment to provide rapid symptom relief while awaiting the full effect of other therapies.