What is the initial treatment for a patient with Graves' disease?

Initial Treatment for Graves' Disease

Methimazole is the preferred first-line treatment for patients with newly diagnosed Graves' disease, typically administered for 12-18 months with regular monitoring of thyroid function. 1

Diagnostic Confirmation

• Confirm diagnosis with TSH, Free T4, and consider TSH receptor antibody testing if clinical features suggest Graves' disease 1
• Physical examination findings of ophthalmopathy or thyroid bruit are diagnostic of Graves' disease and should prompt early endocrine referral 2

First-Line Pharmacological Treatment

• Methimazole (MMI) is the preferred antithyroid drug for most patients with Graves' disease 1, 3
• Initial dosing depends on disease severity:
  • For mild to moderate disease: MMI 15 mg/day 4
  • For severe hyperthyroidism: MMI 30 mg/day 4
• Titrate dose based on thyroid function tests, with goal to maintain FT4 in high-normal range using lowest possible dose 1

Adjunctive Therapy

• Beta-blockers (e.g., atenolol or propranolol) should be added for symptomatic relief of tachycardia, tremor, and anxiety 1, 2
• Monitor thyroid function every 2-3 weeks initially after diagnosis to catch transition to hypothyroidism 2, 1

Monitoring During Treatment

• Check thyroid function every 4-6 weeks initially, then every 2-3 months once stable 1
• Standard duration of therapy is 12-18 months for adults 1, 5
• For children with Graves' disease, a longer course of 24-36 months of MMI is recommended 5

Special Populations

• Pregnancy: Switch from MMI to propylthiouracil (PTU) when planning pregnancy and during the first trimester 5
• PTU is indicated for patients who are intolerant of methimazole 6
• After first trimester, consider switching back to methimazole 1

Treatment Failure or Relapse

• If a patient has persistently high TSH-R-Ab at 12-18 months, options include:
  1. Continue MMI treatment with repeat TSH-R-Ab measurement after an additional 12 months 5
  2. Proceed to definitive therapy with radioactive iodine (RAI) or thyroidectomy 5, 1
• For patients who relapse after completing a course of ATD, definitive treatment is recommended, though continued long-term low-dose MMI can be considered 5

Definitive Treatment Options

• Radioactive iodine (RAI) is contraindicated in pregnancy and in patients with active/severe Graves' orbitopathy 5
• Thyroidectomy should be performed by an experienced high-volume thyroid surgeon 5
• Methimazole is indicated to ameliorate symptoms of hyperthyroidism in preparation for thyroidectomy or radioactive iodine therapy 3

Common Pitfalls to Avoid

• Failing to recognize transition from hyperthyroidism to hypothyroidism, which is common with thyroiditis 1
• Using radioactive iodine in pregnant or breastfeeding women 1
• Overlooking ophthalmopathy or thyroid bruit, which are diagnostic of Graves' disease 2