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

Treatment for Graves' Disease

Methimazole is the first-line treatment for Graves' disease due to its superior efficacy and safety profile compared to other options. 1, 2

Initial Evaluation and Diagnosis

• Check TSH, Free T4, and possibly Free T3 for accurate diagnosis
• Consider TSH receptor antibody testing if clinical features suggest Graves' disease
• Physical examination findings of ophthalmopathy or thyroid bruit are diagnostic of Graves' disease

Treatment Algorithm

First-Line Treatment: Methimazole

• Starting dose:
  • For mild to moderate disease: 10-15 mg daily 1, 3
  • For severe disease: 30-40 mg daily 1, 3
• Duration: 12-18 months 1, 4
• Goal: Maintain Free T4 in high-normal range using lowest possible dose

Monitoring

• Check thyroid function tests every 2-3 weeks initially
• Once stable, monitor every 4-6 weeks 1
• Watch for side effects:
  • Agranulocytosis (presents with sore throat and fever)
  • Hepatitis
  • Vasculitis
  • Thrombocytopenia

Second-Line Treatment Options

Propylthiouracil

• Reserved for specific situations:
  • First trimester of pregnancy
  • Patients intolerant to methimazole
  • Severe liver injury from methimazole 1, 5
• Higher risk of severe liver injury compared to methimazole 1

Radioactive Iodine

• Contraindicated in:
  • Pregnancy
  • Breastfeeding
  • Active/severe orbitopathy 1
• Requires steroid prophylaxis in patients with mild/active orbitopathy

Thyroidectomy

• Consider when:
  • Patient has severe hyperthyroidism unresponsive to medications
  • Large goiter causing compressive symptoms
  • Contraindications to antithyroid medications
• Should be performed by experienced high-volume thyroid surgeon
• Preparation with methimazole and potassium iodide solution before surgery 1

Symptom Management

• Beta-blockers (e.g., propranolol or atenolol) for symptomatic relief of:
  • Tachycardia
  • Tremor
  • Anxiety
  • Heat intolerance
• Continue until thyroid hormone levels normalize 1, 6

Special Considerations

Pregnancy

• Propylthiouracil preferred in first trimester
• Can switch to methimazole in second and third trimesters
• Goal: Maintain Free T4 in high-normal range using lowest possible dose
• Close monitoring as thyroid dysfunction may diminish as pregnancy proceeds 1, 6

Severe Thyrotoxicosis/Thyroid Storm

• Requires hospitalization
• Higher doses of antithyroid medications
• Additional therapies including:
  • Steroids
  • Potassium iodide solution (SSKI)
  • Beta-blockers
  • Supportive care 6, 1

Common Pitfalls to Avoid

• Using propylthiouracil as first-line therapy (higher risk of severe liver injury)
• Inadequate monitoring for side effects of antithyroid medications
• Inappropriate use of radioactive iodine in pregnancy or patients with orbitopathy
• Insufficient beta-blocker dosing for symptom control
• Failure to adjust methimazole dose based on disease severity 1, 3, 7

Evidence-Based Outcomes

• Methimazole 30 mg/day normalizes Free T4 more effectively (96.5%) than propylthiouracil 300 mg/day (78.3%) at 12 weeks 3
• Lower doses of methimazole (15 mg/day) have significantly fewer adverse effects compared to higher doses (30 mg/day) 3, 7
• Hyperthyroidism relapses in approximately 50% of patients after antithyroid drug treatment 4