How should glucocorticoid replacement be dosed to mimic normal physiology in Addison's disease?

How should glucocorticoid replacement be dosed to mimic normal physiology in Addison's disease?

• A. Once daily hydrocortisone
• B. Hydrocortisone divided into two or three doses to approximate circadian rhythm, with separate mineralocorticoid if needed
• C. Dexamethasone once daily
• D. Prednisone twice daily

Answer: (B)

The main idea is to reproduce the body’s natural daily cortisol pattern. In healthy people, cortisol rises in the early morning to help wakefulness and energy, then declines throughout the day. To mimic this, hydrocortisone is given in two or three split doses rather than once daily. A larger morning dose provides the early peak, with smaller doses later in the day helping to maintain levels without keeping them elevated overnight. Because aldosterone (a mineralocorticoid) may also be deficient in Addison’s disease, a separate mineralocorticoid replacement (like fludrocortisone) is added when needed to keep blood pressure and electrolytes in balance. Long-acting steroids, such as dexamethasone, aren’t ideal because they don’t reproduce the natural diurnal rhythm and can cause excessive suppression of the pituitary-adrenal axis or Cushing-like effects. Similarly, prednisone or once-daily regimens don’t align with the normal cortisol circadian pattern as well as divided hydrocortisone does. So the best approach is hydrocortisone divided into two or three doses to approximate the circadian rhythm, with separate mineralocorticoid replacement if required.

The main idea is to reproduce the body’s natural daily cortisol pattern. In healthy people, cortisol rises in the early morning to help wakefulness and energy, then declines throughout the day. To mimic this, hydrocortisone is given in two or three split doses rather than once daily. A larger morning dose provides the early peak, with smaller doses later in the day helping to maintain levels without keeping them elevated overnight. Because aldosterone (a mineralocorticoid) may also be deficient in Addison’s disease, a separate mineralocorticoid replacement (like fludrocortisone) is added when needed to keep blood pressure and electrolytes in balance.

Long-acting steroids, such as dexamethasone, aren’t ideal because they don’t reproduce the natural diurnal rhythm and can cause excessive suppression of the pituitary-adrenal axis or Cushing-like effects. Similarly, prednisone or once-daily regimens don’t align with the normal cortisol circadian pattern as well as divided hydrocortisone does.

So the best approach is hydrocortisone divided into two or three doses to approximate the circadian rhythm, with separate mineralocorticoid replacement if required.