Which are notable adverse effects of spironolactone?

• A. Hyperkalemia; gynecomastia
• B. Hypokalemia; constipation
• C. Hyponatremia; rash
• D. Hypokalemia; tachycardia

Answer: (B)

Spironolactone’s notable adverse effects are hyperkalemia and gynecomastia. It blocks aldosterone’s action in the distal nephron, which reduces potassium excretion and can raise serum potassium, especially in patients with kidney disease, those on ACE inhibitors or ARBs, or those taking NSAIDs. The antiandrogen effects of spironolactone explain gynecomastia and breast tenderness in men and can cause menstrual changes in women. Together, these two effects capture the most clinically important and distinctive risks of this medication. Other potential effects like hypokalemia, tachycardia, hyponatremia, constipation, or rash are less characteristic or less specific to spironolactone’s profile.