What are the treatment options for hyperthyroidism?

Treatment Options for Hyperthyroidism

The primary treatment options for hyperthyroidism include antithyroid medications, radioactive iodine ablation, and surgical thyroidectomy, with the choice depending on the underlying cause, severity of symptoms, and patient-specific factors. 1, 2

Diagnosis and Evaluation

• Hyperthyroidism should be confirmed biochemically with thyroid function tests showing low TSH and elevated free T4 and/or free T3 levels 3
• Further diagnostic workup may include TSH-receptor antibodies, thyroid peroxidase antibodies, thyroid ultrasonography, and scintigraphy to determine the specific etiology 3
• Common causes include Graves' disease (70%), toxic nodular goiter (16%), subacute thyroiditis (3%), and drug-induced hyperthyroidism (9%) 3

Treatment Approaches Based on Etiology

Graves' Disease

• Antithyroid medications are the preferred initial treatment for Graves' disease 3

  • Methimazole (MMI) is the drug of choice due to fewer side effects, once-daily dosing, lower cost, and better availability 4
  • Starting dose is typically 10-30 mg daily as a single dose 4
  • Propylthiouracil (PTU) is indicated for patients intolerant to methimazole or during pregnancy 5, 4
  • PTU dosing is typically 100-300 mg every 6 hours 4
  • Standard treatment course is 12-18 months, with approximately 50% recurrence rate 3
  • Long-term treatment (5-10 years) is associated with fewer recurrences (15%) 3

• Beta-blockers (e.g., propranolol or atenolol) should be used for symptomatic relief, particularly in the initial phase before antithyroid medications take effect 6

• Radioactive iodine ablation is commonly used in the United States, especially for patients with:

  • Recurrent hyperthyroidism after antithyroid drug treatment
  • Contraindications to antithyroid medications
  • Patient preference for definitive treatment 1

• Thyroidectomy is indicated for patients who:

  • Have failed or are intolerant to medical therapy
  • Have large goiters causing compressive symptoms
  • Have suspicious thyroid nodules
  • Prefer surgical management 1, 2

Toxic Nodular Goiter

• Primarily treated with radioactive iodine (131I) or thyroidectomy 3
• Radiofrequency ablation is a newer, less commonly used option 3

Thyroiditis

• Typically self-limited with the hyperthyroid phase resolving within weeks 6
• Treatment is supportive with beta-blockers for symptomatic relief 6
• Monitor for transition to hypothyroidism, which is the most common outcome 6

Management Based on Severity

Mild Hyperthyroidism (Grade 1)

• Continue immune checkpoint inhibitors if that's the cause
• Beta-blockers for symptomatic relief
• Close monitoring of thyroid function every 2-3 weeks 6

Moderate Hyperthyroidism (Grade 2)

• Consider holding immune checkpoint inhibitors until symptoms improve
• Consider endocrine consultation
• Beta-blockers for symptomatic relief
• Hydration and supportive care 6

Severe Hyperthyroidism (Grade 3-4)

• Hold immune checkpoint inhibitors until symptoms resolve
• Mandatory endocrine consultation
• Beta-blockers, hydration, and supportive care
• Consider hospitalization for severe cases
• Additional medical therapies may include steroids, potassium iodide solution (SSKI), or thionamides 6

Special Considerations

Pregnancy

• Propylthiouracil is preferred in the first trimester due to lower risk of congenital anomalies 6, 4
• Methimazole can be used after the first trimester 6
• Goal is to maintain FT4 or FTI in the high-normal range using the lowest possible thioamide dosage 6
• Monitor FT4 or FTI every 2-4 weeks 6
• Radioactive iodine is absolutely contraindicated during pregnancy 6
• Thyroidectomy should be reserved for women who do not respond to thioamide therapy 6

Breastfeeding

• Both methimazole and propylthiouracil are considered safe during breastfeeding 6, 4
• Women should not breastfeed for four months after treatment with radioactive iodine 6

Monitoring and Follow-up

• For patients on antithyroid medications, monitor thyroid function tests regularly to adjust dosing 6
• Watch for side effects of antithyroid medications, including:
  • Agranulocytosis (presents with sore throat and fever)
  • Hepatitis
  • Vasculitis
  • Thrombocytopenia 6
• Monitor for transition from hyperthyroidism to hypothyroidism, especially in thyroiditis 6

Complications of Untreated Hyperthyroidism

• Cardiac arrhythmias and heart failure 2
• Osteoporosis 2
• Adverse pregnancy outcomes 2
• Increased mortality 3, 2
• Thyroid storm (life-threatening emergency) 3

Pitfalls and Caveats

• Single daily dosing of methimazole (15 mg) is more effective than single daily dosing of propylthiouracil (150 mg) in achieving euthyroidism 7
• Thyroiditis is often misdiagnosed as Graves' disease, but treatment approaches differ significantly 6
• Patients with mild subclinical hyperthyroidism may not require treatment unless they are older than 65 years or have persistent TSH levels below 0.1 mIU/L 2
• Always consider the possibility of central hypothyroidism (low TSH with low FT4) which requires different evaluation and management 6