What treatment helps hypothyroidism (low thyroid)?

Treatment for Hypothyroidism (Low Thyroid)

Levothyroxine sodium is the primary medication for treating hypothyroidism and should be used as first-line therapy for all patients with low thyroid function. 1

Diagnosis and Assessment

• Hypothyroidism is diagnosed biochemically, with elevated TSH and low free T4 levels indicating overt primary hypothyroidism 2
• Before initiating treatment, confirm elevated TSH with repeat testing after 3-6 weeks, as 30-60% of high TSH levels normalize on repeat testing 3
• Measure both TSH and free T4 to distinguish between subclinical hypothyroidism (normal free T4) and overt hypothyroidism (low free T4) 3

Treatment Algorithm Based on TSH Levels

• For TSH >10 mIU/L (with normal or low T4): Initiate levothyroxine therapy regardless of symptoms 3
• For TSH 4.5-10 mIU/L with normal T4 (subclinical hypothyroidism):
  • Treatment decisions should be individualized based on symptoms, presence of TPO antibodies, and risk factors 3
  • Many persons with mildly elevated TSH (4.5 to 10.0 mIU/L) spontaneously revert to a euthyroid state over time 4

Levothyroxine Dosing Guidelines

• Standard adult dosing: Approximately 1.6 mcg/kg/day for patients <70 years without cardiac disease 3
• For elderly patients (>70 years) or those with cardiac disease: Start with a lower dose of 25-50 mcg/day and titrate gradually 3, 1
• Dosage adjustments should be made in increments of 12.5-25 mcg based on TSH monitoring 3

Monitoring Protocol

• Monitor TSH every 6-8 weeks while titrating hormone replacement 3
• Once adequately treated, repeat testing every 6-12 months or if symptoms change 3
• About 25% of patients on levothyroxine are unintentionally maintained on doses high enough to make TSH undetectable, which could increase risk for osteoporosis, fractures, abnormal cardiac output, or ventricular hypertrophy 4, 3

Special Populations

Pregnancy

• Women with hypothyroidism who are pregnant or planning pregnancy should be treated to normalize TSH 1
• TSH should be monitored every 6-8 weeks during pregnancy as requirements often increase 1, 5
• Untreated maternal hypothyroidism during pregnancy is associated with complications including spontaneous abortion, gestational hypertension, pre-eclampsia, stillbirth, and premature delivery 5

Complications of Untreated Hypothyroidism

• Serious complications include heart failure, myxedema coma, and in pregnant women, increased risk of preeclampsia 1, 2
• Common symptoms include fatigue (68%-83%), weight gain (24%-59%), cognitive issues (45%-48%), cold intolerance, constipation, and dry skin 2, 6
• These conditions are mostly the result of a low metabolic rate in the body 6

Alternative Treatments

• Combined levothyroxine plus liothyronine (T3) treatment has been evaluated in multiple clinical trials 7
• In some studies, patients preferred the combination therapy, but clear advantages have not been consistently demonstrated 7, 8
• Until clear advantages are proven, levothyroxine alone should remain the treatment of choice 7

Common Pitfalls to Avoid

• Overtreatment: Can lead to iatrogenic hyperthyroidism, increasing risk for osteoporosis, fractures, abnormal cardiac output, and ventricular hypertrophy 3
• Undertreatment: Risks include persistent hypothyroid symptoms, adverse effects on cardiovascular function, lipid metabolism, and quality of life 3
• Failure to recognize transient hypothyroidism: May lead to unnecessary lifelong treatment 3

Long-term Management

• Hypothyroidism typically requires lifelong hormone replacement therapy 6
• With appropriate treatment, symptoms can be effectively managed, and most people with the condition can lead normal, healthy lives 6
• Lifestyle modifications like eating healthy food and exercising regularly can help manage symptoms and improve quality of life 6