Interaksi Estrogen terkonjugasi dan Levotiroksin dan liotironin

Hypothyroidism Estrogen administration leads to increased thyroid-binding globulin (TBG) levels.

Women with normal thyroid function can compensate for the increased TBG by making more thyroid hormone, thus maintaining free T 4 and T 3 serum concentrations in the normal range.

Women dependent on thyroid hormone replacement therapy who are also receiving estrogens may require increased doses of their thyroid replacement therapy.

These women should have their thyroid function monitored in order to maintain their free thyroid hormone levels in an acceptable range.

Increased thyroid-binding globulin (TBG) leading to increased circulating total thyroid hormone, as measured by protein-bound iodine (PBI), T 4 levels (by column or by radioimmunoassay) or T 3 levels by radioimmunoassay.

Estrogen, Oral Contraceptives — Estrogens tend to increase serum thyroxine-binding globulin (TBg).

In a patient with a nonfunctioning thyroid gland who is receiving thyroid replacement therapy, free levothyroxine may be decreased when estrogens are started thus increasing thyroid requirements.

Therefore, patients without a functioning thyroid gland who are on thyroid replacement therapy may need to increase their thyroid dose if estrogens or estrogen-containing oral contraceptives are given.