التداخل بين ديكساميثازون وليفوثيروكسين

When concomitant administration of corticosteroids and levothyroxine is required, administration of corticosteroid should precede the initiation of levothyroxine therapy to avoid adrenal crisis.

In addition, patients with hypopituitarism, primary adrenal insufficiency, or congenital adrenal hyperplasia, altered thyroid function, or pheochromocytoma may be at risk for adverse endocrine events.

Considerations for Use in Patients with Altered Thyroid Function Metabolic clearance of corticosteroids is decreased in hypothyroid patients and increased in hyperthyroid patients.

Changes in thyroid status of the patient may necessitate a dose adjustment of the corticosteroid.

Failure to do so may precipitate an acute adrenal crisis when thyroid hormone therapy is initiated, due to increased metabolic clearance of glucocorticoids by thyroid hormone.

Androgens/Anabolic Steroids Asparaginase Glucocorticoids Slow-Release Nictonic Acid These drugs may decrease serum TBG concentration.

Glucocorticoids (e.g., Dexamethasone ≥ 4 mg/day) Short-term administration of large doses of glucocorticoids may decrease serum T 3 concentrations by 30% with minimal change in serum T 4 levels.

However, long-term glucocorticoid therapy may result in slightly decreased T 3 and T 4 levels due to decreased TBG production (See above).

Nephrosis, severe hypoproteinemia, severe liver disease, acromegaly, androgens, and corticosteroids decrease TBG concentration.