Initial Treatment for Hyperthyroidism
Beta-blockers (such as atenolol or propranolol) are the initial treatment for hyperthyroidism, particularly for symptomatic relief, while antithyroid medications like methimazole are the primary definitive treatment option. 1
Diagnostic Approach
- Check TSH and Free T4 levels to confirm hyperthyroidism; T3 can be helpful in highly symptomatic patients with minimal FT4 elevations 1
- Consider TSH receptor antibody testing if clinical features suggest Graves' disease (e.g., ophthalmopathy, T3 toxicosis) 1
- Physical examination findings of ophthalmopathy or thyroid bruit are diagnostic of Graves' disease and should prompt early endocrine referral 1
Treatment Algorithm Based on Severity
Grade 1 (Asymptomatic or Mild Symptoms)
- Beta-blockers (e.g., atenolol or propranolol) for symptomatic relief 1
- Close monitoring of thyroid function every 2-3 weeks to detect transition to hypothyroidism 1
- For persistent thyrotoxicosis (>6 weeks), consider endocrine consultation 1
Grade 2 (Moderate Symptoms)
- Consider holding immune checkpoint inhibitors if applicable until symptoms return to baseline 1
- Beta-blockers for symptomatic relief 1
- Hydration and supportive care 1
- Consider endocrine consultation 1
Grade 3-4 (Severe Symptoms)
- Hold immune checkpoint inhibitors if applicable until symptoms resolve 1
- Mandatory endocrine consultation 1
- Beta-blockers, hydration, and supportive care 1
- Consider hospitalization in severe cases 1
- Additional medical therapies may include steroids, potassium iodide (SSKI), or thionamides (methimazole or propylthiouracil) 1
Definitive Treatment Options
Antithyroid Medications
- Methimazole is the drug of choice for most patients 2, 3
- Starting dose should not exceed 15-20 mg/day (dose-dependent risk of agranulocytosis) 2
- Propylthiouracil should be reserved for patients who cannot tolerate methimazole or during the first trimester of pregnancy 4, 2
- WARNING: Propylthiouracil can cause severe liver injury and acute liver failure, sometimes fatal, requiring liver transplantation in some cases 4
Other Treatment Options
- Radioactive iodine ablation (most widely used treatment in the United States) 5
- Antithyroid drugs should be stopped at least one week prior to radioiodine to reduce risk of treatment failure 2
- Surgical thyroidectomy (typically performed as near-total thyroidectomy) 2, 5
Special Considerations
Thyroiditis
- Often self-limited with initial hyperthyroidism resolving in weeks with supportive care 1
- Most commonly transitions to hypothyroidism or occasionally returns to normal 1
- Beta-blockers are the mainstay of treatment during the hyperthyroid phase 1
Graves' Disease
- Antithyroid drugs are preferred initial treatment 6
- Recurrence after 12-18 month course occurs in approximately 50% of patients 6
- Risk factors for recurrence: age <40 years, FT4 ≥40 pmol/L, high TSH-binding inhibitory immunoglobulins, larger goiter size 6
- Long-term treatment (5-10 years) is associated with fewer recurrences (15%) than short-term treatment 6
Toxic Nodular Goiter
- Usually treated with radioiodine or thyroidectomy 6
Common Pitfalls and Caveats
- Failure to recognize thyroiditis as a cause of transient hyperthyroidism 1
- Not monitoring for transition from hyperthyroidism to hypothyroidism in thyroiditis 1
- Using propylthiouracil as first-line therapy (increased risk of severe liver injury) 4, 2
- Not stopping antithyroid drugs before radioiodine therapy (reduces effectiveness) 2
- Inadequate beta-blockade for symptom control while awaiting definitive treatment 1