Spironolactone is added as the fourth agent in resistant hypertension. Its blood pressure-lowering effect in this setting is primarily mediated by antagonism of which receptor?
- A Angiotensin II type 1 (AT1) receptor
- B Mineralocorticoid receptor in the distal nephron ✓
- C Alpha-1 adrenergic receptor
- D Endothelin A receptor
Correct answer: B. Mineralocorticoid receptor in the distal nephron
Explanation
Spironolactone competitively antagonizes the mineralocorticoid receptor in the distal convoluted tubule and collecting duct, promoting natriuresis and reducing volume. In resistant hypertension, aldosterone excess is common, and spironolactone at 25-50 mg is the most effective fourth-line agent per PATHWAY-2. AT1 blockade is by ARBs, alpha-1 blockade by prazosin, and endothelin antagonism by bosentan.
Reference: Williams Textbook of Endocrinology, 14th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.