Examples of Mineralocorticoid and Glucocorticoid Agents
For hormonal replacement therapy in adrenal insufficiency, use fludrocortisone 0.05-0.2 mg once daily as the mineralocorticoid and hydrocortisone 15-25 mg daily (divided into 2-3 doses) as the glucocorticoid.
Mineralocorticoid Replacement
The synthetic mineralocorticoid fludrocortisone (9-fluorocortisol) is the standard and essentially only option for mineralocorticoid replacement 1.
Dosing specifics:
- Adults: 0.05-0.2 mg once daily, typically taken in the morning 1, 2
- The dose relates to individual fluid, electrolyte intake, and losses
- May require 50-100% temporary dose increases in hot climates or with excessive sweating 1
Key monitoring parameters:
- Clinical assessment: salt craving, postural hypotension, peripheral edema 1
- Blood pressure (sitting and standing positions)
- Serum electrolytes (sodium and potassium)
- Plasma renin activity in the upper reference range indicates adequate dosing 1
Glucocorticoid Replacement
Multiple glucocorticoid options exist, with hydrocortisone as the preferred first-line agent 3:
Primary options:
- Hydrocortisone: 15-25 mg daily (physiologic dose equivalent), divided into 2-3 doses 4, 1
- Cortisone acetate: 20-30 mg daily, divided into 2-3 doses 2, 3
Alternative synthetic glucocorticoids (with dose equivalents to 15-25 mg hydrocortisone) 4:
- Prednisone/Prednisolone: 4-6 mg daily
- Methylprednisolone: 3-5 mg daily
- Dexamethasone: 0.25-0.5 mg daily
Critical Interaction Between Glucocorticoid and Mineralocorticoid Therapy
Most glucocorticoids possess some mineralocorticoid activity, which affects fludrocortisone dosing requirements 5, 6:
- Hydrocortisone has inherent mineralocorticoid activity
- Prednisolone has less mineralocorticoid activity than hydrocortisone, requiring higher fludrocortisone doses 1
- Dexamethasone has NO mineralocorticoid activity, requiring full mineralocorticoid replacement 1
The glucocorticoids with minimal mineralocorticoid effects (and thus most selective) include prednisolone, budesonide, beclomethasone, and betamethasone 5. However, synthetic glucocorticoids may have undesirable metabolic long-term effects, making hydrocortisone the preferred first-line treatment 3.
Common Pitfalls to Avoid
Glucocorticoid over-replacement signs: weight gain, insomnia, peripheral edema, hypertension 1
Mineralocorticoid under-replacement signs: salt craving, postural dizziness, lethargy—these symptoms persist in many treated patients, suggesting chronic under-replacement is common 7
Do NOT use plasma ACTH levels to guide glucocorticoid dosing—this leads to over-replacement, as appropriately replaced patients often have elevated ACTH 1
Avoid licorice and grapefruit juice—they potentiate the mineralocorticoid effect of hydrocortisone 1
Phenytoin increases fludrocortisone metabolism, requiring higher replacement doses 1