Does long-term prednisone (corticosteroid) use cause thyroid dysfunction?

From the FDA Drug Label

Corticosteroids can produce reversible hypothalamic-pituitary adrenal (HPA) axis suppression with the potential for corticosteroid insufficiency after withdrawal of treatment. Metabolic clearance of corticosteroids is decreased in hypothyroid patients and increased in hyperthyroid patients. There is an enhanced effect of corticosteroids on patients with hypothyroidism.

The FDA drug label does not directly answer the question of whether long-term prednisone use causes thyroid dysfunction, but it does mention that metabolic clearance of corticosteroids is decreased in hypothyroid patients and that there is an enhanced effect of corticosteroids on patients with hypothyroidism 1, 1. However, this information is not sufficient to conclude that long-term prednisone use causes thyroid dysfunction.

• The label discusses the effect of thyroid status on corticosteroid metabolism, but it does not provide direct evidence of thyroid dysfunction caused by prednisone.
• It mentions hypothyroidism as a condition that may affect corticosteroid therapy, but it does not state that prednisone causes hypothyroidism.
• Therefore, based on the available information, no conclusion can be drawn about the relationship between long-term prednisone use and thyroid dysfunction.

From the Research

Long-term prednisone use does not directly cause thyroid dysfunction in most patients, but it may influence thyroid hormone metabolism and require periodic monitoring of thyroid function. Prednisone, a corticosteroid commonly prescribed for inflammatory and autoimmune conditions, primarily affects the hypothalamic-pituitary-adrenal axis rather than directly impacting the thyroid gland. However, prolonged use (typically months to years) may influence thyroid hormone metabolism by altering the conversion of T4 to T3 (the active thyroid hormone), potentially leading to changes in thyroid function tests without causing true thyroid disease.

Key Considerations

• Patients on long-term prednisone therapy (usually doses above 5-10mg daily for more than 3 months) should have their thyroid function monitored periodically as part of routine care 2.
• The relationship between prednisone and thyroid function is complex - prednisone can sometimes mask symptoms of underlying thyroid disorders or affect the treatment requirements for patients already diagnosed with thyroid conditions.
• If you're on long-term prednisone therapy and experience symptoms like unusual fatigue, weight changes, or temperature sensitivity, discuss thyroid testing with your healthcare provider, as these could indicate thyroid dysfunction requiring evaluation.

Evidence Summary

• A study from 2021 provides an overview of the causes of thyroid function disorders and guidance on management, but does not specifically address the effect of prednisone on thyroid function 2.
• An older study from 1996 found that long-term prednisone treatment is associated with suppressed GH levels and with an increase in total IGF-1 levels, which may have implications for thyroid hormone metabolism 3.
• Another study from 1978 found that prednisone can decrease serum TSH levels without significant changes in levels of serum T4, T3, and thyroxine binding globulin (TBG) in hypothyroid patients 4.
• A study from 2011 found that anti-inflammatory doses of prednisone administered every other day did not interfere with thyroid hormone monitoring in hypothyroid dogs 5.
• A study from 2007 found that lipodystrophy and neuropsychiatric disorders are common adverse events of long-term prednisone therapy, but does not specifically address thyroid dysfunction 6.