From the Guidelines
The first line treatment for hypothyroidism is levothyroxine (T4), a synthetic form of thyroid hormone, and patients should follow up with TSH testing every 6-12 months once they are stable on an appropriate dose.
Treatment Details
- Treatment typically begins with a daily dose of 1.6 mcg/kg of body weight, though elderly patients or those with cardiac disease may start at a lower dose of 25-50 mcg daily 1.
- After initiating therapy, TSH levels should be checked 6-8 weeks later to assess if dose adjustment is needed.
- Levothyroxine should be taken on an empty stomach, 30-60 minutes before breakfast or 3-4 hours after the last meal of the day, to ensure optimal absorption.
- Certain medications (calcium supplements, iron, antacids) and foods can interfere with absorption, so these should be separated from levothyroxine intake by at least 4 hours.
Monitoring and Follow-up
- The goal of treatment is to normalize TSH levels, typically to a range of 0.5-4.0 mIU/L for most adults, which restores the body's normal metabolic state by replacing the deficient thyroid hormone.
- Patients should be monitored for symptoms of over-replacement (anxiety, palpitations, insomnia) or under-replacement (persistent fatigue, weight gain, cold intolerance).
- Follow-up TSH testing is recommended every 6-12 months once the patient is stable on an appropriate dose 1.
Special Considerations
- For patients with severe symptoms or life-threatening consequences, hospitalization and urgent intervention may be necessary, and thyroid replacement therapy should be started promptly 1.
- In patients with grade 3 or 4 hypothyroidism, ICI therapy should be held until symptoms resolve to grade 2 or better, and standard thyroid replacement therapy should be initiated 1.
From the FDA Drug Label
The general aim of therapy is to normalize the serum TSH level In adult patients with primary hypothyroidism, monitor serum TSH levels after an interval of 6 to 8 weeks after any change in dosage. In patients on a stable and appropriate replacement dosage, evaluate clinical and biochemical response every 6 to 12 months and whenever there is a change in the patient’s clinical status
The first line treatment for hypothyroidism is levothyroxine sodium tablets. Patients should follow up with their doctor to monitor serum TSH levels after an interval of 6 to 8 weeks after any change in dosage, and then every 6 to 12 months to evaluate clinical and biochemical response. 2
From the Research
First Line Treatment for Hypothyroidism
- The first line treatment for hypothyroidism is monotherapy with levothyroxine (LT4), titrated to maintain the level of thyrotropin within a euthyroid reference range 3, 4, 5, 6.
- Levothyroxine is the drug of choice for the treatment of hypothyroidism, and it is usually taken on an empty stomach 5.
- The current guideline-based management of hypothyroidism recommends monotherapy with levothyroxine (LT4) 3.
Follow-up Schedule
- Follow-up involves regular assessment of levels of TSH and symptom relief 5.
- Patients with hypothyroidism should have their TSH levels checked regularly to ensure that they are within the euthyroid reference range 3, 5.
- The majority of individuals with hypothyroidism can be diagnosed and treated by their outpatient primary care providers, with follow-up involving regular assessment of TSH levels and symptom relief 5.
Combination Therapy
- There is no strong evidence to support the use of combination therapy with levothyroxine (LT4) and liothyronine (LT3) for the treatment of hypothyroidism 7, 4, 6.
- Some studies have suggested that combination therapy may have beneficial effects on mood, quality of life, and psychometric performance, but these findings are not consistent and more research is needed to fully understand the potential benefits and risks of combination therapy 3, 4.