What are the treatment options for managing hyperthyroidism?

Management of Hyperthyroidism

All patients with hyperthyroidism should be started immediately on beta-blockers (atenolol or propranolol) for symptomatic relief, particularly for cardiovascular manifestations like tachycardia, while definitive treatment is determined based on the underlying etiology. 1

Immediate Symptomatic Management

• Beta-blockers are the first-line symptomatic treatment and should be initiated immediately in all hyperthyroid patients, especially those with thyrotoxicosis, tachycardia, or hypertension 1, 2
• Non-dihydropyridine calcium channel antagonists (diltiazem or verapamil) serve as alternatives when beta-blockers are contraindicated 1
• Beta-blockers provide essential rate control in patients with concurrent atrial fibrillation 1

Definitive Treatment Selection

The choice of definitive therapy depends on the underlying cause and patient-specific factors:

For Graves' Disease and Toxic Nodular Goiter

Three definitive treatment options exist:

1. Antithyroid Medications (Methimazole or Propylthiouracil)

• Methimazole is FDA-approved for Graves' disease and toxic multinodular goiter when surgery or radioactive iodine is not appropriate, and to ameliorate symptoms before definitive therapy 3
• Methimazole inhibits thyroid hormone synthesis but does not affect existing circulating hormones 3
• Treatment courses typically last 12-18 months for potential remission in Graves' disease 4, 5
• Long-term treatment (5-10 years) is associated with lower recurrence rates (15%) compared to short-term treatment (50% recurrence) 5
• Mandatory monitoring for agranulocytosis, hepatitis, vasculitis, and thrombocytopenia is required 2, 3
• Patients must report immediately any sore throat, skin eruptions, fever, or general malaise 3

2. Radioactive Iodine Ablation

• Radioactive iodine is the most widely used treatment in the United States 6
• This is the treatment of choice for toxic nodular goiter 4
• The only long-term sequela is radioiodine-induced hypothyroidism 4
• Absolutely contraindicated during pregnancy and lactation; pregnancy should be avoided for 4 months following administration 2, 4
• Should not be used in Graves' disease with ophthalmopathy as it may cause deterioration; corticosteroid cover may reduce this risk 4, 7

3. Thyroidectomy

• Indicated for patients who have failed or are intolerant to medical therapy 2
• Specific indications include: concurrent thyroid cancer, pregnancy (when medical therapy fails), compressive symptoms, large goiters causing neck compression, and Graves' disease with ophthalmopathy 4, 7
• Subtotal or near-total thyroidectomy for Graves' disease; thyroid lobectomy for toxic adenomas 7
• Patients must be rendered euthyroid with antithyroid medications preoperatively and maintained on beta-blockers 7

For Destructive Thyroiditis

• Usually mild and self-limited, resolving within weeks with supportive care alone 1
• Beta-blockers provide symptomatic relief 1
• Monitor thyroid function every 2-3 weeks to detect transition to hypothyroidism 1, 2
• Steroids are reserved only for severe cases 5

Special Population Considerations

Pregnancy

• Propylthiouracil is preferred in the first trimester due to lower risk of congenital anomalies 2
• Methimazole can be used after the first trimester 2
• Radioactive iodine is absolutely contraindicated 2
• Thyroidectomy is reserved for women who do not respond to thioamide therapy 2
• Methimazole crosses the placenta and can induce goiter and cretinism in the fetus 3

Hyperthyroidism with Atrial Fibrillation

• Beta-blockers are essential for rate control 1
• Anticoagulation decisions should be guided by CHA2DS2-VASc score, not hyperthyroidism alone 1

Severe/Life-Threatening Hyperthyroidism (Thyroid Storm)

• Hospitalization is necessary 1
• Mandatory endocrine consultation is required 1, 2
• Provide beta-blockers, hydration, and supportive care 1, 2
• Consider additional therapies: steroids, SSKI (saturated solution of potassium iodide), or thionamides (methimazole or propylthiouracil) 1
• Immune checkpoint inhibitors should be held until symptoms resolve if this is the underlying cause 2

Critical Monitoring and Drug Interactions

Laboratory Monitoring

• Prothrombin time should be monitored during methimazole therapy, especially before surgical procedures, as methimazole may cause hypoprothrombinemia 3
• Thyroid function tests should be monitored periodically; rising TSH indicates need for lower maintenance dose 3
• Weekly or biweekly thyroid function monitoring in nursing mothers on methimazole 3

Important Drug Interactions

• Oral anticoagulants (warfarin) may have increased activity; additional PT/INR monitoring is needed 3
• Beta-blocker doses may need reduction when hyperthyroid patients become euthyroid due to decreased clearance 3
• Digitalis glycoside doses may need reduction as serum levels increase when patients become euthyroid 3
• Theophylline clearance decreases and doses may need reduction when patients become euthyroid 3

Common Pitfalls to Avoid

• Do not delay beta-blocker initiation while awaiting definitive diagnosis 1
• Do not use radioactive iodine in Graves' ophthalmopathy without corticosteroid cover 4, 7
• Do not perform thyroidectomy without first achieving euthyroid state with antithyroid medications 7
• Do not overlook the need for frequent monitoring for agranulocytosis in patients on antithyroid drugs 2, 3
• Do not use methimazole in first trimester pregnancy; switch to propylthiouracil 2