Pharmacology · single question
Dexamethasone is best classified as which of the following?
Show answer and explanation
Correct answer: B. A glucocorticoid receptor agonist
- A. An antagonist would BLOCK glucocorticoid effects — mifepristone is an example.
- B. Correct. DEXAMETHASONE is a potent synthetic GLUCOCORTICOID AGONIST with essentially NO mineralocorticoid activity — which is precisely why it is chosen when anti-inflammatory potency is wanted without sodium and water retention. It is roughly 25–30 times more potent than hydrocortisone with a long duration of action, making it the corticosteroid of choice for reducing postoperative oedema and trismus after third molar surgery.
- C. Spironolactone is the mineralocorticoid antagonist, a potassium-sparing diuretic.
- D. Fludrocortisone is the mineralocorticoid agonist, used in adrenal insufficiency for salt retention.