What is the initial treatment for hyperthyroidism?

Initial Treatment for Hyperthyroidism

The initial treatment for hyperthyroidism should be a beta-blocker (such as atenolol or propranolol) for symptomatic relief, followed by specific therapy based on the severity and cause of hyperthyroidism. 1

Assessment and Diagnosis

• Before initiating treatment, confirm hyperthyroidism with thyroid function tests (low TSH with elevated free T4 and/or T3) 1
• Consider TSH receptor antibody testing if clinical features suggest Graves' disease (e.g., ophthalmopathy, diffuse goiter) 1
• The most common causes of hyperthyroidism are Graves' disease (70%), toxic nodular goiter (16%), thyroiditis (3%), and medication-induced (9%) 2

Treatment Algorithm Based on Severity

Grade 1 (Asymptomatic or Mild Symptoms)

• Continue immune checkpoint inhibitors if that's the cause 1
• Initiate beta-blocker therapy (e.g., atenolol 25-50mg daily or propranolol) for symptomatic relief 1
• Monitor thyroid function every 2-3 weeks to detect transition to hypothyroidism, which is common with thyroiditis 1
• For persistent thyrotoxicosis (>6 weeks), consider endocrine consultation 1

Grade 2 (Moderate Symptoms)

• Consider holding immune checkpoint inhibitors until symptoms return to baseline if that's the cause 1
• Initiate beta-blocker therapy for symptomatic control 1
• Provide hydration and supportive care 1
• Consider endocrine consultation 1
• For persistent thyrotoxicosis (>6 weeks), refer to endocrinology for additional workup and possible medical thyroid suppression 1

Grade 3-4 (Severe Symptoms)

• Hold immune checkpoint inhibitors until symptoms resolve if that's the cause 1
• Mandatory endocrine consultation for all patients 1
• Beta-blocker therapy, hydration, and supportive care 1
• Consider hospitalization in severe cases 1
• Inpatient endocrine consultation can guide additional medical therapies including steroids, potassium iodide (SSKI), or thionamide (methimazole or propylthiouracil) 1

Specific Treatment Options

Antithyroid Medications

• Methimazole is generally the drug of choice due to fewer severe side effects 3
• Propylthiouracil should be reserved for patients who cannot tolerate methimazole or during the first trimester of pregnancy 4
• CAUTION: Propylthiouracil carries a black box warning for severe liver injury and acute liver failure 4

Thyroiditis Management

• Thyroiditis is self-limited and the initial hyperthyroidism generally resolves in weeks with supportive care 1
• The hyperthyroid phase of thyroiditis often transitions to hypothyroidism or returns to normal 1
• Beta-blockers are the mainstay of treatment during the hyperthyroid phase 1
• High-dose corticosteroids are not routinely required for thyroiditis 1

Graves' Disease Management

• Initial treatment with antithyroid drugs (methimazole or propylthiouracil) 2
• Physical examination findings of ophthalmopathy or thyroid bruit are diagnostic of Graves' disease and should prompt early endocrine referral 1
• Definitive treatment options include radioactive iodine ablation (most widely used in the US) or surgical thyroidectomy 5

Important Considerations and Pitfalls

• Monitor for transition to hypothyroidism, which is common after the hyperthyroid phase of thyroiditis 1
• Untreated hyperthyroidism can lead to cardiac arrhythmias, heart failure, osteoporosis, and is associated with increased mortality 6
• In pregnant women, propylthiouracil may be the treatment of choice during the first trimester, but carries risk of liver injury 4
• Beta-blockers provide rapid symptomatic relief while awaiting the effects of definitive therapy 1
• Patients with severe symptoms may require hospitalization for intensive monitoring and treatment 1