From the Guidelines
For a 69-year-old female with a TSH of 5.87, I recommend monitoring her TSH and free T4 levels for 3-4 weeks before initiating treatment to determine whether there is recovery to normal, as elevated TSH can be seen in the recovery phase of thyroiditis, especially if her FT4 remains in the reference range and she is asymptomatic 1. This approach is based on the most recent guideline update from the Journal of Clinical Oncology, which suggests that asymptomatic patients with FT4 in the reference range can be monitored before treating to determine whether there is recovery to normal within 3-4 weeks 1. Some key considerations for this patient include:
- Checking free T4 levels to confirm the diagnosis and rule out other causes of elevated TSH
- Evaluating for symptoms of hypothyroidism such as fatigue, cold intolerance, or constipation
- Considering potential causes of hypothyroidism, including autoimmune thyroiditis by checking thyroid peroxidase antibodies
- If treatment is initiated, starting with a lower dose of levothyroxine, such as 25-50 mcg daily, due to her age and potential sensitivity to thyroid hormone replacement 1
- Schedule follow-up testing in 6-8 weeks to check TSH and free T4 levels, with a target TSH of 1-3 mIU/L for this age group
- Dose adjustments should be made gradually, typically in 12.5-25 mcg increments, to minimize the risk of overtreatment or cardiac effects 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. Failure of the serum T4 to increase into the upper half of the normal range within 2 weeks of initiation of levothyroxine sodium therapy and/or of the serum TSH to decrease below 20 IU per litre within 4 weeks may indicate the patient is not receiving adequate therapy
The next steps for a 69-year-old female with elevated Thyroid-Stimulating Hormone (TSH) levels of 5.87 would be to:
- Initiate levothyroxine therapy to normalize the serum TSH level
- Monitor serum TSH levels after 6 to 8 weeks of therapy to assess the response to treatment
- Adjust the dosage as needed to achieve a normal TSH level, with careful consideration of potential food or drug interactions 2