What is the recommended treatment for Hashimoto's Thyroiditis?

Treatment of Hashimoto's Thyroiditis

Levothyroxine (T4) is the standard treatment for Hashimoto's thyroiditis when hypothyroidism develops, with dosing individualized based on age, comorbidities, and TSH targets. 1

Diagnosis and Clinical Presentation

Hashimoto's thyroiditis is the most common autoimmune thyroid disorder characterized by:

• Elevated thyroid peroxidase (TPO) antibodies
• Often presents with a painless goiter
• Progressive development of hypothyroidism
• May initially be euthyroid before developing hypothyroidism

Treatment Approach

When to Initiate Treatment

• Treatment is indicated when patients develop overt hypothyroidism
• Consider treatment when TSH > 10 mIU/L even if asymptomatic 1
• Consider treatment in subclinical hypothyroidism (TSH 4-10 mIU/L) with:
  • Positive anti-thyroid peroxidase antibodies
  • Presence of goiter
  • Symptomatic patients
  • Pregnant women or women planning pregnancy 1

Medication Selection

• Levothyroxine is the first-line treatment 1, 2
• Liothyronine (T3) can be used in patients allergic to levothyroxine or desiccated thyroid 3

Dosing Guidelines

Starting doses for levothyroxine:

• Patients under 70 years without cardiac disease: 1.6 mcg/kg/day 1
• Elderly patients or those with cardiac conditions: 25-50 mcg/day 1
• Pregnant women: Adjust to maintain trimester-specific TSH reference range 1, 2

Monitoring and Follow-up

• Check TSH 6-8 weeks after initiating therapy or changing dose 1
• Once stable, monitor every 6-12 months 1
• Target TSH ranges:
  • General population: 0.5-2.0 mIU/L 1
  • Elderly patients: 1.0-4.0 mIU/L 1
  • Pregnant women: Trimester-specific reference ranges 1, 2

Special Considerations

Pregnancy

• Pregnant women require close monitoring with TSH checks every 4 weeks until stable 1, 2
• Maintain TSH in trimester-specific reference range 2
• May need dose increases of 12.5-25 mcg/day during pregnancy 2
• Return to pre-pregnancy dose immediately after delivery 2

Elderly Patients

• Start with lower doses (25-50 mcg/day) 1
• Target higher TSH range (1.0-4.0 mIU/L) 1
• Treatment decisions for patients over 80-85 years should consider potential risks of treatment 1

Prophylactic Treatment

Some evidence suggests that prophylactic levothyroxine in euthyroid Hashimoto's thyroiditis may:

• Reduce thyroid volume 4
• Decrease antibody levels 4
• However, this is not standard practice and requires further research

Potential Risks and Side Effects

• Overtreatment can increase risk of atrial fibrillation and osteoporosis, particularly in elderly patients 1
• Excessive thyroid hormone replacement should be avoided 1
• Undertreatment may result in persistent hypothyroid symptoms

Clinical Pearls

• Hashimoto's thyroiditis typically follows a progressive course, often requiring lifelong thyroid hormone replacement 5, 6
• Unlike other forms of thyroiditis (postpartum, subacute), Hashimoto's rarely resolves spontaneously 6
• Levothyroxine may reduce goiter size in addition to treating hypothyroidism 5
• Medication absorption can be affected by food, coffee, calcium supplements, and certain medications - advise taking on empty stomach 1