What is the initial treatment for hyperthyroidism?

Initial Treatment for Hyperthyroidism

Beta-blockers (atenolol 25-50 mg daily or propranolol) are the initial treatment for symptomatic hyperthyroidism to provide rapid symptom relief while definitive therapy is being planned. 1

Immediate Symptomatic Management

• Start beta-blocker therapy immediately for symptomatic patients presenting with tachycardia, palpitations, anxiety, tremor, or heat intolerance 1
• Titrate atenolol to achieve heart rate <90 bpm if blood pressure allows 1
• Beta-blockers work rapidly to control cardiac symptoms while thyroid hormone levels remain elevated 1

Definitive Treatment Selection (Based on Etiology)

For Thyroiditis (Self-Limited)

• Supportive care with beta-blockers only - do not start antithyroid drugs 1
• Monitor thyroid function every 2-3 weeks to detect transition to hypothyroidism 1
• Hyperthyroid phase typically resolves within weeks, most commonly progressing to hypothyroidism 1

For Graves Disease or Toxic Nodules (Autonomous Production)

Antithyroid drug therapy is the initial definitive treatment, with methimazole as first-line agent 1, 2, 3, 4:

• Methimazole 10-20 mg daily (single dose) is preferred over propylthiouracil 2, 5
• Starting dose should not exceed 15-20 mg/day to minimize risk of agranulocytosis 2
• Propylthiouracil is reserved only for:
  • First trimester of pregnancy or just prior to conception 1, 6, 5
  • Patients who cannot tolerate methimazole 6
  • Critical warning: Propylthiouracil causes severe liver failure requiring transplantation or death 6, 2

Important Clinical Pitfalls

• Do NOT use high-dose corticosteroids routinely for hyperthyroidism - they are not indicated 1
• Distinguish thyroiditis from Graves disease early: TSH receptor antibodies and clinical features (ophthalmopathy, thyroid bruit) indicate Graves disease requiring different management 1
• Stop antithyroid drugs at least one week before radioiodine to reduce treatment failure risk 2
• Monitor for agranulocytosis (fever, sore throat) especially in first 3 months of thionamide therapy 6, 2

Severity-Based Approach

Grade 1-2 (Mild-Moderate Symptoms):

• Continue evaluation while starting beta-blocker 1
• Add antithyroid drug once etiology confirmed (if Graves/toxic nodules) 1

Grade 3-4 (Severe/Life-Threatening):

• Hold immune checkpoint inhibitors if applicable 1
• Hospitalize for severe cases 1
• Endocrine consultation mandatory 1
• Consider additional therapies: steroids, SSKI, or thionamides under specialist guidance 1
• Hydration and supportive care 1