Fludrocortisone is classified as which type of corticosteroid?

• A. Glucocorticoid
• B. Mineralocorticoid
• C. Progestin
• D. Androgen

Answer: (B)

Fludrocortisone is best thought of by its primary action as a mineralocorticoid. It mainly mimics aldosterone, acting on the distal tubules of the kidney to increase sodium reabsorption and potassium excretion, which expands extracellular fluid and helps raise blood pressure. This electrolyte-regulating, water-retaining role is the hallmark of mineralocorticoid activity, distinguishing fludrocortisone from glucocorticoids (which primarily influence metabolism and immune responses) and from progestins or androgens (other hormone classes). In clinical use, fludrocortisone is employed to replace mineralocorticoid activity in conditions like Addison’s disease, underscoring its primary classification as a mineralocorticoid.