What is the initial management approach for Graves' disease?

Initial Management of Graves' Disease

The initial management of Graves' disease should be antithyroid drug therapy with methimazole (MMI) as the preferred medication for a 12-18 month course, using the lowest possible dosage that maintains free T4 or free T4 index in the high-normal range. 1, 2

Diagnosis and Initial Evaluation

• Initial laboratory testing should include TSH and free T4 or free T4 index (FTI) to confirm thyrotoxicosis 1
• TSH receptor antibodies (TRAb) testing is recommended for accurate diagnosis and differential diagnosis of Graves' disease 2
• Thyroid ultrasound showing a hypervascular and hypoechoic thyroid gland supports the diagnosis 2
• Physical examination should assess for signs of ophthalmopathy or thyroid bruit, which are diagnostic of Graves' disease 1

Antithyroid Drug Therapy

First-line Treatment:

• Methimazole (MMI) is the preferred antithyroid drug for initial treatment 1, 2
  • Starting dose typically 10-30 mg daily as a single dose 3
  • Lower doses (15 mg daily) may be as effective as higher doses (30 mg daily) in controlling thyroid hormone levels 4
  • Goal is to maintain free T4 or FTI in the high-normal range using the lowest possible dosage 1

Monitoring:

• Measure free T4 or FTI every 2-4 weeks initially to adjust medication dosage 1
• After stabilization, monitor thyroid function regularly throughout the 12-18 month treatment course 2
• TSH-R-Ab measurement is recommended prior to stopping antithyroid drug treatment 2

Special Considerations:

• For women planning pregnancy or in first trimester: switch from MMI to propylthiouracil (PTU) due to potential teratogenic effects of MMI 2, 3
• For children with Graves' disease: a longer course (24-36 months) of MMI is recommended 2

Symptomatic Management

• Beta-blockers (e.g., propranolol, atenolol) can be used for symptomatic relief until antithyroid therapy reduces thyroid hormone levels 1
• Hydration and supportive care should be provided for patients with moderate to severe symptoms 1

Monitoring for Adverse Effects

• Monitor for potential side effects of antithyroid drugs, particularly within the first 90 days of therapy 5:
  • Agranulocytosis (presents with sore throat and fever; requires CBC and drug discontinuation) 1
  • Hepatitis 1
  • Vasculitis 1
  • Thrombocytopenia 1

Treatment Decisions After Initial Course

• If TSH-R-Ab remains high at 12-18 months, options include 2:

  1. Continue MMI treatment with repeat TSH-R-Ab measurement after an additional 12 months
  2. Proceed to definitive therapy with radioactive iodine (RAI) or thyroidectomy

• For patients who relapse after completing a course of antithyroid drugs:

  • Definitive treatment (RAI or thyroidectomy) is recommended 2
  • Alternatively, continued long-term low-dose MMI can be considered 2

Definitive Treatment Options

Radioactive Iodine (RAI):

• Contraindicated in patients with active/severe orbitopathy 2
• Steroid prophylaxis is warranted in patients with mild/active orbitopathy receiving RAI 2
• Contraindicated during pregnancy 1
• Patients should not breastfeed for four months after RAI treatment 1

Surgery (Near-total Thyroidectomy):

• Should be performed by an experienced high-volume thyroid surgeon 2
• Preferred for patients with concomitant suspicious thyroid nodules, large goiters, or moderate to severe thyroid eye disease 5
• Potential complications include hypoparathyroidism and vocal cord paralysis 5

Special Situations

Thyroid Storm

• Presents with fever, tachycardia out of proportion to fever, altered mental status, vomiting, diarrhea, and cardiac arrhythmia 1
• Requires immediate treatment with multiple medications including antithyroid drugs (propylthiouracil or methimazole) and potassium iodide solutions 1
• Hospitalization is necessary for severe cases 1

Pregnancy

• Women with Graves' disease should be monitored during pregnancy for normal heart rate and appropriate fetal growth 1
• The newborn's physician needs to be aware of maternal Graves' disease due to risk of neonatal thyroid dysfunction 1