Dose adjustment in hypothyroidism secondary to hypopituitarism
For a patient with hypothyroidism secondary to hypopituitarism, base levothyroxine dose adjustments on symptoms and serum T4 concentration—aim for a serum T4 concentration in the upper half of the reference range. To measure the serum T4 concentration, the sample should be collected before the daily dose of levothyroxine; sampling after the daily dose can spuriously elevate the T4 concentration.
Do not use serum TSH concentration as a basis for dose adjustment in hypopituitarism, as a low serum TSH concentration is an expected finding in hypothyroidism secondary to hypopituitarism.