From the FDA Drug Label
Metabolic clearance of corticosteroids is decreased in hypothyroid patients and increased in hyperthyroid patients. Changes in thyroid status of the patient may necessitate adjustment in dosage
- Prednisone may affect thyroid levels indirectly by altering the metabolic clearance of corticosteroids in patients with hypothyroidism or hyperthyroidism.
- The dosage of prednisone may need to be adjusted in patients with changes in thyroid status 1.
From the Research
Yes, prednisone can affect thyroid levels, as evidenced by its ability to decrease thyroid-stimulating hormone (TSH) levels and alter the conversion of the thyroid hormone T4 to the more active T3, with the most recent and highest quality study suggesting that short-term prednisone treatment may be an alternative strategy for managing subacute thyroiditis 2.
Mechanism of Action
The mechanism behind this interaction involves prednisone's suppression of the hypothalamic-pituitary axis and its influence on peripheral thyroid hormone metabolism, as supported by a study published in 1978, which found that prednisone decreased mean serum TSH levels without significant changes in levels of serum T4, T3, and thyroxine binding globulin (TBG) 3.
Clinical Implications
Patients with existing thyroid conditions or those on long-term prednisone therapy should have their thyroid function monitored regularly, as prednisone may mask symptoms or complicate management of their condition, and the risk of hypothyroidism should be considered in the long-term management of hyperthyroidism and hypothyroidism 4.
Key Points
- Prednisone can decrease TSH levels and alter the conversion of T4 to T3
- The effect is typically dose-dependent, with higher doses and longer treatment durations having more significant impacts
- Patients with underlying thyroid disease should have their thyroid function monitored regularly
- Short-term prednisone treatment may be an alternative strategy for managing subacute thyroiditis
- The mechanism involves suppression of the hypothalamic-pituitary axis and influence on peripheral thyroid hormone metabolism
- Regular assessment of TSH levels and symptom relief is important in the management of hypothyroidism, and outpatient primary care clinicians can use shared decision-making to determine the best initiation method for each individual 5.