What are the treatment options for hyperthyroidism?

Treatment of Hyperthyroidism

The treatment of hyperthyroidism involves three primary modalities—antithyroid drugs, radioactive iodine therapy, and surgery—with methimazole as the preferred first-line antithyroid medication for most patients, beta-blockers for immediate symptom control, and definitive therapy selected based on patient-specific factors including pregnancy status, goiter size, and presence of ophthalmopathy. 1

Immediate Symptomatic Management

• Beta-blockers (atenolol or propranolol) should be initiated immediately for symptomatic relief, particularly in patients with cardiac manifestations such as tachycardia, tremor, and palpitations 1
• Beta-blockers provide rapid symptom control while waiting for antithyroid medications to reduce thyroid hormone levels to therapeutic range, which typically takes several weeks 1
• Continue beta-blocker therapy until thioamide therapy successfully reduces thyroid hormone levels 1

Primary Pharmacological Treatment

First-Line Antithyroid Drug Selection

• Methimazole is the preferred antithyroid drug due to its longer half-life, once-daily dosing convenience, lower cost, better availability, and fewer severe side effects compared to propylthiouracil 2
• Methimazole at 15 mg once daily is significantly more effective than propylthiouracil 150 mg once daily, achieving euthyroidism four times more effectively and reducing T3 and T4 levels more rapidly 3, 4
• Starting doses typically range from 10-30 mg daily as a single dose 5
• Monitor thyroid function tests every 2-3 weeks initially, then every 4-6 weeks once stable, with dose adjustments based on clinical response and laboratory values 1

Propylthiouracil: Limited Indications

• Propylthiouracil is reserved exclusively for patients intolerant to methimazole and for whom surgery or radioactive iodine is not appropriate 6
• Propylthiouracil is also used to ameliorate symptoms before thyroidectomy or radioactive iodine therapy in methimazole-intolerant patients 6
• Typical dosing is 100-300 mg every 6 hours due to its shorter half-life 5

Critical Safety Monitoring

• Immediately discontinue thioamides if agranulocytosis, hepatitis, vasculitis, or thrombocytopenia develop 1
• These represent life-threatening complications requiring urgent alternative management strategies 1

Definitive Treatment Options

Radioactive Iodine Therapy

• Radioactive iodine is increasingly used as first-line definitive therapy and is particularly effective for toxic nodular goiter 7
• Well-tolerated with the primary long-term consequence being development of hypothyroidism requiring lifelong thyroid hormone replacement 1, 7
• Absolutely contraindicated during pregnancy and lactation; pregnancy must be avoided for 4 months following administration 1, 7
• May worsen Graves' ophthalmopathy; consider corticosteroid prophylaxis in patients with significant eye disease 7
• Can be used in all age groups except children 7

Surgical Management

• Near-total or total thyroidectomy is recommended for patients with large goiters causing compressive symptoms, suspicious nodules, or severe ophthalmopathy 1
• Surgery is rarely used for Graves' disease unless radioiodine is refused or contraindicated 7
• Requires lifelong thyroid hormone replacement post-operatively 1
• Goal is to cure underlying pathology while potentially preserving some thyroid function, though this is increasingly uncommon with modern surgical approaches 7

Special Clinical Scenarios

Pregnancy Management

• Propylthiouracil is preferred in pregnancy due to methimazole's association with aplasia cutis and choanal/esophageal atresia 5
• Maintain FT4 or free thyroxine index in the high-normal range using the lowest possible thioamide dosage 1
• Monitor FT4 or FTI every 2-4 weeks throughout pregnancy 1
• Both propylthiouracil and methimazole are safe during breastfeeding 1, 5

Thyroiditis-Induced Hyperthyroidism

• This condition is self-limited and requires only supportive care with beta-blockers, not antithyroid drugs 1
• Typically resolves within weeks 1
• Close monitoring is essential as most patients transition to primary hypothyroidism requiring thyroid hormone replacement 1

Severe Hyperthyroidism/Thyroid Storm

• Mandatory hospitalization with endocrine consultation 1
• Aggressive management includes beta-blockers, high-dose antithyroid drugs, hydration, and supportive care 1
• Consider additional therapies including corticosteroids, saturated solution of potassium iodide (SSKI), or emergency surgery 1

Treatment Algorithm by Severity

Mild Hyperthyroidism

• Continue beta-blockers for symptomatic relief 1
• Initiate methimazole (preferred) with thyroid function monitoring every 2-3 weeks 1

Moderate Hyperthyroidism

• Beta-blockers, hydration, and supportive care 1
• Consider holding immune checkpoint inhibitors if applicable 1
• Endocrine consultation recommended 1

Severe Hyperthyroidism

• Hospitalization mandatory 1
• Endocrine consultation required 1
• Aggressive multimodal therapy as outlined above 1

Long-Term Considerations

• Long-term follow-up is necessary even after successful treatment due to risk of recurrence or development of hypothyroidism 1
• Antithyroid drug therapy for Graves' disease typically continues for 12-18 months to induce long-term remission 7
• Antithyroid drugs will not cure toxic nodular goiter, which requires definitive therapy 7
• Cardiovascular complications are the chief cause of death in patients over 50 years with hyperthyroidism, making prompt recognition and effective management critical 8